A geometric model processing method for airflow organization simulation

Abstract

This invention provides a geometric model processing method for airflow organization simulation, belonging to the field of geometric model processing technology, to solve one of the technical problems of difficulty in detecting defects in geometric models through manual inspection, low processing efficiency, and unreliable subsequent mesh generation quality. The method includes: automatically filtering and retaining target graphics and information, and deleting other irrelevant geometry; when the geometric model is two-dimensional, performing surface region repair on the two-dimensional model; when the geometric model is three-dimensional, diagnosing and repairing sharp corners, small gaps, small spacing between surfaces, and intersections between volumes in the geometric model that have a small impact on the flow field but affect the number and quality of subsequent meshes; checking the repair quality of the geometric model item by item, and if the coordinate information of the target graphics and the geometric parameters of the geometric model do not meet the preset conditions, adjusting the repair threshold or iteration parameters for iterative repair until the geometric model meets the preset conditions. This method improves model processing efficiency and model quality.

Description

Technical Field

[0001] This invention relates to the field of geometric model processing technology, and in particular to a geometric model processing method for airflow organization simulation. Background Technology

[0002] Airflow organization simulation technology has become an important tool for environmental quality analysis in industries such as electronics, aerospace, and biopharmaceuticals. Some equipment models include various small connectors, tiny holes, and machined chamfers. While the flow field influence of these elements is negligible for airflow simulation in large spaces, they severely affect the mesh generation quality, leading to simulation failure or non-convergence.

[0003] Commercial modeling software in related technologies has the function of partially repairing geometric models, but it requires manual inspection and repair of each geometric model one by one. Some geometric defects are difficult to detect and the cost of remodeling is very high. Summary of the Invention

[0004] The purpose of this invention is to provide a geometric model processing method for airflow organization simulation, so as to solve one of the technical problems of difficulty in detecting defects by manual inspection of geometric models, low processing efficiency, and unreliable quality of subsequent mesh generation.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a geometric model processing method for airflow organization simulation, comprising:

[0007] Based on the feature information of the geometric model, the target graphics and information are automatically filtered and retained, while other irrelevant geometry is deleted.

[0008] When the geometric model is a two-dimensional model, the two-dimensional model is repaired by surface repair; when the surface is not closed, if there is only one pair of unbalanced points in the surface, the endpoints are merged and connecting segments are added to repair the surface; if there are multiple pairs of unbalanced points in the surface, the principle of minimum chain length is used, and the nearest paired vertex is found for each vertex in order of vertex distance from the origin from near to far to repair the surface.

[0009] When a region is self-intersecting, identify the self-intersecting line segments within the region and divide them at the intersection points to form sub-segments, then extract simple closed loops to repair the region.

[0010] When regions intersect, if there are collinear regions, merge the regions to repair them; if there are regions sharing a common area, calculate the intersection area between the regions and merge the intersection area into either of the two intersecting regions, or merge the two intersecting regions as a whole.

[0011] The quality of the repair of the geometric model is checked item by item. If the coordinate information of the target graphic and the geometric parameters of the geometric model do not meet the preset conditions, the repair threshold or iteration parameters are adjusted to carry out iterative repair until the geometric model meets the preset conditions.

[0012] According to at least one embodiment of the present invention, the merging of endpoints and the addition of connecting segments to repair the surface region includes:

[0013] Keeping the slope of the line segment containing the in-degree imbalance point unchanged, calculate the coordinates of the intersection point of the two line segments based on the coordinates of the in-degree imbalance point and the slope of the line segment. Combine a pair of in-degree imbalance points at the intersection point of the two line segments and construct a line segment to perform region closure repair.

[0014] When two line segments have no intersection in the direction of the imbalance point or the intersection point is outside the boundary region, the supplementary line segment connects a pair of in-degree imbalance points to perform surface closure repair; if the length of the supplementary line segment is less than the preset length threshold, one of the pair of in-degree imbalance points is fixed and the two points are merged.

[0015] According to at least one embodiment of the present invention, the method further includes performing line segment repair on the two-dimensional model; when the angle between the line segment and the horizontal or vertical direction is less than a first angle threshold, the endpoint of the line segment closer to the origin is fixed, and the other endpoint is moved until the line segment is horizontal or vertical.

[0016] When the difference between the included angle of the two line segments and 90° is less than the first included angle threshold, fix one of the two line segments and move the endpoint of the other line segment until the two line segments are perpendicular.

[0017] When there are multiple approximately parallel line segments within the same surface region, select multiple line segments whose slope difference is less than a preset slope difference threshold, and use the average slope of the multiple line segments as the final repair value.

[0018] According to at least one embodiment of the present invention, the method further includes distance repair of the two-dimensional model; when the distance between two points is less than a first distance threshold, merging is performed using the midpoint between the two points, or the intersection of the extension lines of the line segments containing the two points, as the merging point; or...

[0019] Keeping other points fixed, move two points or one of them along the extension of the line between them; or keep the slope of the line segment containing the two points fixed, move the two points or one of them parallel to each other until the distance between the two points is greater than or equal to a first distance threshold; or...

[0020] When there is no wireless segment connection between two points within the same area, the midpoint between the two points or one of the points is used as the merging point, and the redundant line segments formed by the merging are deleted after merging.

[0021] According to at least one embodiment of the present invention, when the distance between a point and a line is less than a second distance threshold, a first auxiliary line perpendicular to the line is drawn through the point to be repaired. When the point and the line are in the same area, the point or line is moved along the first auxiliary line until the distance between them is greater than or equal to the second distance threshold.

[0022] When a point and a line are in different areas, move the point or line along the direction of the first auxiliary line until they merge.

[0023] According to at least one embodiment of the present invention, the method further includes repairing the included angle between line segments of the two-dimensional model; when the included angle between two line segments is less than a second included angle threshold, under the condition that the second included angle threshold, the preset length threshold and the triangle side angle relationship are satisfied, the two line segments forming the included angle are cut off by the second auxiliary line to form a new line segment and included angle, and the original included angle less than the second included angle threshold and the line segment connected to the included angle are deleted.

[0024] According to at least one embodiment of the present invention, the geometric model further includes a three-dimensional model, and the method further includes:

[0025] When the length of a line segment is less than a preset length threshold, it is defined as a short line. When the coordinates of the short line are located on or outside the outer contour line of the 3D model, the short line is deleted. If the line segments of the outer contour line are missing after the short line is deleted and a surface cannot be generated, surface non-closure repair is performed.

[0026] When the coordinates of the short line are located inside the outer contour of the 3D model, the surfaces containing the short line are repaired between each other.

[0027] According to at least one embodiment of the present invention, the method further includes: when the distance between the surfaces is less than a preset surface distance threshold, moving the smaller of the two surfaces along a preset direction to merge with the other surface to form a coplanar surface, wherein the preset direction refers to the distribution direction from one surface to another.

[0028] According to at least one embodiment of the present invention, it further includes: when two faces intersect and the included angle is less than a third included angle threshold, and there is a gap between the two faces, drawing the angle bisector of the included angle of the two faces and a third auxiliary line perpendicular to the angle bisector, wherein the two ends of the third auxiliary line intersect the two faces respectively and the length is greater than or equal to a preset length threshold.

[0029] When the two faces have the same height, an auxiliary face is generated by the third auxiliary line and the intersection line of the two intersecting faces and filled to the included angle. The filled area is merged with the original 3D model.

[0030] When the heights of the two faces are not the same, an auxiliary face is generated on the lower face using the third auxiliary line and the intersection line of the two intersecting faces, and filled to the included angle. The filled area is merged with the original 3D model.

[0031] When two faces intersect and the included angle is less than the third included angle threshold, and there is a solid between the two faces, draw the angle bisector of the included angle between the two faces and a third auxiliary line perpendicular to the angle bisector. The two ends of the third auxiliary line intersect the two faces respectively and the length is greater than or equal to the preset length threshold. Generate an auxiliary surface with the intersection of the third auxiliary line and the intersection line of the two intersecting faces. Cut and delete the included angle portion of the solid along the direction perpendicular to the auxiliary surface.

[0032] According to at least one embodiment of the present invention, the method further includes: when bodies intersect and are embedded, merging the bodies using a combination method to form a new body; or,

[0033] After dividing the two bodies using their intersecting surfaces as dividing planes, three new bodies are formed. The embedded parts of the two bodies are deleted from the newly formed bodies, and the other two newly formed bodies are retained.

[0034] According to at least one embodiment of the present invention, when there are multiple approximately parallel line segments in the same area, the endpoint closer to the origin of the coordinate system is taken as the fixed point and the other endpoint is taken as the moving endpoint, and the parallelism of the multiple approximately parallel line segments is repaired in order of increasing distance between the fixed point and the origin of the coordinate system.

[0035] According to at least one embodiment of the present invention, when there are multiple geometric relationships to be repaired on the surface, the repair is performed in the order of surface repair, line segment repair, distance repair, and included angle repair.

[0036] According to at least one embodiment of the present invention, for geometric relationships of the same type to be repaired, the interior of the surface domain is repaired first, and then the inter-surface domains are repaired; among the points to be repaired, the point closest to the origin of the coordinate system is taken as the starting point, and each point to be repaired is repaired in a clockwise order; when repairing the surface domain, the surface domain is not closed first, and then the surface domains intersect; when repairing the distance, the distance between points is repaired first, and then the distance between points and lines is repaired.

[0037] In one or more technical solutions provided in the exemplary embodiments of the present invention, at least one of the following beneficial effects can be achieved.

[0038] The geometric model processing method for airflow organization simulation provided by the exemplary embodiment of the present invention first performs automated cleaning of the geometric model to remove irrelevant geometric details and minor features, thereby improving model processing efficiency and enhancing the quality of the model used for airflow organization simulation.

[0039] Then, the two-dimensional model is automatically checked and repaired, including surface region non-closure repair and surface region intersection repair. Surface region intersection repair is further subdivided into surface region self-intersection repair and surface region intersection repair. Surface region non-closure repair is further subdivided into closure repair with only one pair of in-degree imbalance points within the surface region and closure repair with multiple pairs of in-degree imbalance points.

[0040] For cases with only one pair of in-degree imbalance points, closure repair is achieved by merging endpoints and adding connecting segments. For cases with multiple pairs of in-degree imbalance points, global path planning is performed based on the minimum chain length principle. For each vertex, the nearest paired vertex is found and a connecting segment is added to repair the region, following the order of vertex distance from the origin from near to far. When regions self-intersect, the self-intersecting segments within the region are identified and segmented at the intersection point to form sub-segments. Simple closed loops are extracted to repair the region. When regions intersect, if collinear regions exist, they are merged to repair the region. If shared regions exist, the intersection area between regions is calculated and merged into either of the two intersecting regions, or the two intersecting regions are merged entirely. Based on the above region repair methods, the problems of mesh generation failure or computational non-convergence caused by region defects in the geometric model are effectively solved.

[0041] Finally, the quality of the repaired geometric model is checked item by item. If the coordinate information of the target graphic and the geometric parameters of the geometric model do not meet the preset conditions, the repair threshold or iteration parameters are adjusted for iterative repair until the geometric model meets the preset conditions. Only after the geometric model meets the preset conditions can it proceed to the subsequent mesh generation process. At this point, the accuracy and integrity of the geometric model are fully guaranteed, significantly improving the success rate of mesh generation and the reliability of the calculation results. This method achieves adaptive optimization of the geometric model through a closed-loop feedback mechanism, effectively solving the technical problems of low efficiency and unreliable quality caused by reliance on manual intervention in traditional modeling. It improves the automation level and model quality of preprocessing for airflow organization simulation, and is particularly suitable for high-precision simulation needs in complex scenarios such as clean rooms. Attached Figure Description

[0042] The accompanying drawings illustrate exemplary embodiments of the invention and, together with the description thereof, serve to explain the principles of the invention. These drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification.

[0043] Figure 1 This is a diagram illustrating the area closure repair process according to an embodiment of the present invention;

[0044] Figure 2 This is a diagram illustrating the self-intersection repair process of a surface region according to an embodiment of the present invention;

[0045] Figure 3This is a diagram illustrating the process of inter-regional intersection repair according to an embodiment of the present invention;

[0046] Figure 4 This is a diagram illustrating the process of merging and repairing the distance between two points according to an embodiment of the present invention;

[0047] Figure 5 This is one of the diagrams illustrating the moving and repairing process of the distance between two points according to an embodiment of the present invention;

[0048] Figure 6 This is the second diagram illustrating the process of moving and repairing the distance between two points according to an embodiment of the present invention;

[0049] Figure 7 This is a diagram illustrating the merging-deletion repair process of the distance between two points according to an embodiment of the present invention;

[0050] Figure 8 This is a diagram illustrating the process of repairing the distance between points and lines within a surface region according to an embodiment of the present invention;

[0051] Figure 9 This is a diagram illustrating the process of repairing the distance between points and lines between areas according to an embodiment of the present invention;

[0052] Figure 10 This is a diagram illustrating the process of repairing included angles within a surface region according to an embodiment of the present invention;

[0053] Figure 11 This is a diagram illustrating the process of repairing the angle between surface regions according to an embodiment of the present invention;

[0054] Figure 12 This is a diagram illustrating various geometric repair processes within a surface region according to an embodiment of the present invention;

[0055] Figure 13 This is one of the diagrams illustrating various geometric repair processes between surface regions according to an embodiment of the present invention;

[0056] Figure 14 This is the second diagram of multiple geometric repair processes between surface regions according to an embodiment of the present invention;

[0057] Figure 15 This is a diagram illustrating the process of repairing the distance between surfaces according to an embodiment of the present invention;

[0058] Figure 16 This is one of the diagrams illustrating the process of repairing the angle between surfaces according to an embodiment of the present invention;

[0059] Figure 17 This is the second diagram illustrating the process of repairing the angle between surfaces according to an embodiment of the present invention.

[0060] Figure 18 This is the third diagram illustrating the process of repairing the angle between surfaces according to an embodiment of the present invention;

[0061] Figure 19 This is one of the body-to-body intersection repair process diagrams according to an embodiment of the present invention;

[0062] Figure 20 This is the second diagram of the body-to-body intersection repair process according to an embodiment of the present invention;

[0063] Figure 21A This is one of the diagrams illustrating the complex model repair process according to an embodiment of the present invention;

[0064] Figure 21B This is the second diagram of the complex model repair process according to an embodiment of the present invention;

[0065] Figure 21C This is the third diagram of the complex model repair process according to an embodiment of the present invention;

[0066] Figure 21D This is the fourth diagram of the complex model repair process according to an embodiment of the present invention;

[0067] Figure 22A This is one of the pipeline model repair process diagrams according to an embodiment of the present invention;

[0068] Figure 22B This is the second diagram of the pipeline model repair process according to an embodiment of the present invention;

[0069] Figure 22C This is the third diagram of the pipeline model repair process according to an embodiment of the present invention;

[0070] Figure 23 This is a diagram illustrating the civil engineering model repair process according to an embodiment of the present invention;

[0071] Figure 24A This is a pre-cleaning view of a fan filter unit model according to an embodiment of the present invention;

[0072] Figure 24B This is a cleaned model of a fan filter unit according to an embodiment of the present invention;

[0073] Figure 25A This is a view of the three-dimensional geometric model before cleaning, according to an embodiment of the present invention;

[0074] Figure 25B This is a diagram of the cleaned three-dimensional geometric model according to an embodiment of the present invention;

[0075] Figure 26 This is a logic block diagram of the geometric feedback adjustment module according to an embodiment of the present invention. Detailed Implementation

[0076] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0077] Example 1

[0078] This embodiment provides a geometric model processing method for airflow organization simulation, including the following steps:

[0079] Step S100: Based on the feature information of the geometric model, automatically filter and retain the target graphics and information, and delete other irrelevant geometry.

[0080] The geometric model can be two-dimensional or three-dimensional. For two-dimensional geometry, only the target layer or model information is retained, while dimensions, text, and redundant points / lines / surfaces / volumes are deleted; the retained target layer or model information can be used to diagnose and repair lines and surfaces.

[0081] like Figure 24A As shown, the fan filter unit model includes the building outline 10, columns 20, fan filter units 30, return air duct 40, labeled text 50, and labeled elevation 60. Based on the environmental airflow organization simulation requirements, the supply air needs to retain the geometric shapes of the building outline 10 and fan filter units 30. By identifying the attributes and position coordinates of the building outline 10 and fan filter units 30, the system automatically identifies and retains the target objects, deleting other irrelevant geometry. After cleaning, as shown... Figure 24B As shown.

[0082] For 3D geometry, the main problems in the geometric model that have little impact on the flow field but seriously affect the number and quality of meshes in the later stages, such as sharp corners, small gaps, small spacing between surfaces, perpendicularity of intersecting surfaces, and intersection of volumes, are diagnosed and repaired.

[0083] like Figure 25A As shown, the 3D geometric model includes civil engineering model T10, pipes T20, equipment T30, rainproof shelter T40, etc. Based on the filtering parameters, such as filtering based on target system attributes, only civil engineering model T10 and pipes T20 are retained. After filtering and retaining the target model, the others are deleted. Then, based on the pipe size information, the filter is set to retain pipes with a diameter greater than or equal to 1500mm. After cleaning, as shown... Figure 25B As shown.

[0084] Step S200: Repair the retained target geometry.

[0085] For two-dimensional geometry, the main repair methods include surface repair, line segment repair, distance repair, and angle repair.

[0086] Step S201, Region Repair, includes automatically identifying and repairing issues such as unclosed regions and intersecting regions.

[0087] Step S2011: Repairing unclosed regions.

[0088] A non-closed region refers to a region where the endpoints do not coincide, there are gaps between line segments, or there is overlap between adjacent line segments. First, flux component analysis, vertex in-degree balance check, and endpoint geometric coincidence check are performed on the geometric model, and points with in-degree imbalance are marked.

[0089] It should be noted that an unbalanced point in in-degree refers to a vertex in a directed graph in graph theory where the in-degree and out-degree values ​​are not equal.

[0090] (1) If there is only one pair of in-degree imbalance points in the region, merge the endpoints and add connecting segments to repair the region.

[0091] Specifically, keeping the slope of the line segment containing the pair of unbalanced points unchanged, the coordinates of the intersection point of the line segment are automatically calculated based on the coordinates of the unbalanced points and the slope of the line segment. The pair of in-degree and out-degree unbalanced points are merged at the intersection point, and a line segment is constructed to repair the unclosed surface region.

[0092] If the line segments have no intersection in the direction of the imbalance point, or the intersection point is outside the boundary area, the two points are repaired by adding a new line segment to connect them. When the length of the added line segment is less than the preset length threshold, one of the points is selected as the fixed point and the two points are merged.

[0093] For example, Figure 1 This is a diagram illustrating the region closure repair process according to an embodiment of the present invention, as shown below. Figure 1 As shown, the in-degree and out-degree of points E and D in the geometric model are unbalanced. Based on the coordinates of E and D and the slopes of AE and CD, the intersection point F is automatically calculated as the merging point. Figure 1 (The intermediate image), merge E and D at point F, and after repair, form a closed region ( Figure 1 (The right side of the image).

[0094] Unless otherwise specified, in the attached diagrams with arrows, the direction of the arrows usually indicates the process diagrams presented sequentially in the repair process. Typically, the first diagram (left or upper left) is the original diagram, the third diagram (right) or the fourth diagram (lower left) is the final repair result diagram, and the middle diagram is an intermediate state diagram of the repair process.

[0095] (2) When there are multiple pairs of vertices with unbalanced in-degree and out-degree in the geometric model, the nearest pair of vertices is found for each vertex to supplement line segments in order of the vertex distance from the origin to the nearest distance, based on the principle of minimum chain length, in order of the vertex distance from the origin to the nearest distance, in order to repair the surface region.

[0096] For neighboring point pairs whose distance is less than the first distance threshold, they are merged first. If the points with unbalanced in-degree and out-degree are scattered, global path planning is required. Specifically, based on the principle of minimum chain length, the nearest paired vertex is found for each vertex in ascending order of distance from the origin, and line segments are added to satisfy the following conditions: the length of the line segment is greater than or equal to a preset length threshold, and the included angle of the line segment is greater than or equal to a second included angle threshold.

[0097] Step S2012: Area intersection repair.

[0098] Step S2012A: When the surface region is self-intersecting, identify the self-intersecting line segments within the surface region and divide them at the intersection points to form sub-segments, extracting simple closed loops to repair the surface region.

[0099] In practical applications, flux component analysis is performed on the geometric model to separate independent surface regions. Simultaneous detection of line segment sets within a single surface region is then conducted. A combination of the Bentley-Ottmann algorithm, bounding box filtering, and parametric equation method is used to filter and mark self-intersecting line segments within the surface region. Finally, surface region repair is performed by segmenting intersecting line segments at their intersection points and extracting simple closed loops based on the segmented sub-segments.

[0100] For example, Figure 2 This is a diagram illustrating the self-intersection repair process of a surface region according to an embodiment of the present invention, as shown below. Figure 2 As shown, AD and BC in region a are self-intersecting. A new dividing point E is added at the intersection point to divide AD and BC respectively, forming new regions b and c. Figure 2 (Right side image).

[0101] Step S2012B: When regions intersect, merge regions to repair them if collinear regions exist.

[0102] Step S2012C: When the regions intersect, if there are regions sharing a common area, calculate the intersecting region between the regions and merge the intersecting region into either of the two intersecting regions, or merge the two intersecting regions as a whole.

[0103] For example, Figure 3 This is a diagram illustrating the inter-regional intersection repair process according to an embodiment of the present invention, such as... Figure 3 As shown, regions a and b intersect. When regions a and b are not allowed to be merged, the intersection region c is calculated based on geometric information. Figure 3 (Second image in the middle) Merge region c with region a, and the repaired result is as follows. Figure 3 As shown in the third image; when merging regions a and b is allowed, merge regions a and b as a whole, and the result after repair is as follows. Figure 3 As shown in the fourth picture.

[0104] Step S202, line segment repair includes horizontal / vertical line segment repair, vertical line segment repair, and parallel line segment repair.

[0105] Step S2021, Line segment horizontal / vertical repair includes: when the angle between the line segment and the horizontal or vertical direction is less than the first angle threshold, fix the endpoint of the line segment that is closer to the origin of the coordinates, and move the other endpoint until the line segment is horizontal or vertical.

[0106] Step S2022, line segment perpendicularity repair includes: when the difference between the included angle of two line segments and 90° is less than the first included angle threshold, fix one of the two line segments and move the endpoint of the other line segment until the two line segments are perpendicular.

[0107] Step S2023, Parallel line segment repair includes: when there are multiple approximately parallel line segments in the same area, select multiple line segments whose slope difference is less than a preset slope difference threshold, and use the average slope of the multiple line segments as the final repair value.

[0108] In practical applications, line segment parallelism repair involves forcibly constraining two approximately parallel line segments within the same surface region to be parallel. The slope of each line segment is calculated separately, and multiple line segments with a slope difference less than a threshold are selected. The average slope of these multiple line segments is used as the final repair value. The distance from the endpoints of the line segments to be repaired to the origin is calculated sequentially. The endpoint closer to the origin is designated as a fixed point, and the other endpoint as a moving endpoint. The parallelism of multiple sets of line segments is repaired in order of increasing distance from the fixed point to the origin.

[0109] Step S203, Distance Repair includes: repairing the distances between points and between points and lines within the selected computational domain.

[0110] Step S2031: When the distance between two points is less than the first distance threshold, perform point-to-point distance repair.

[0111] Step S2031A: Merge the points by using the midpoint between the two points, or the intersection of the line segments extending from one of the points, or the intersection of the line segments containing the two points.

[0112] For example, Figure 4 This is a diagram illustrating the process of merging and repairing the distance between two points according to an embodiment of the present invention, as shown below. Figure 4 As shown, the distance between two points C and D within the region is less than the first distance threshold. Point D is used as the merging point to repair the point-to-point distance. The repaired distance is as follows: Figure 4 The image on the right.

[0113] Step S2031B: Keeping the other points fixed, move two points or one of the points along the extension line between the two points.

[0114] For example, Figure 5This is one of the diagrams illustrating the movement and repair process of the distance between two points according to an embodiment of the present invention, such as... Figure 5 As shown, if the distance between two points E and F within the region is less than the first distance threshold, keep other points within the region fixed, and simultaneously move points E and F in the opposite direction until the distance between the two points is greater than or equal to the first distance threshold, the repaired geometric model is as follows. Figure 5 As shown in the diagram on the right.

[0115] Step S2031C: Keep the slope of the line segment containing the two points fixed, and move the two points or one of the points in parallel until the distance between the two points is greater than or equal to the first distance threshold.

[0116] For example, Figure 6 This is the second diagram illustrating the process of moving and repairing the distance between two points according to an embodiment of the present invention, as shown below. Figure 6 As shown, the distance between point C in region a and point D in region b is less than the first distance threshold. Using the moving point and fixed slope / curvature method, point E is moved along the auxiliary line BE, keeping the slope of line segment DE constant. Simultaneously, point D moves accordingly. The repaired geometric model is as follows. Figure 6 As shown in the diagram on the right.

[0117] Step S2031D: When there is no wireless segment connection between two points in the same area, the midpoint between the two points or one of the points is used as the merging point, and the redundant line segments formed by the merging are deleted after merging.

[0118] For example, Figure 7 This is a diagram illustrating the merging-deletion repair process for the distance between two points according to an embodiment of the present invention. Figure 7 As shown, the distance between points D and E within the same area is less than the first distance threshold, and there is no line segment connection between D and E. A merging method is used to merge the two points into point D. Then, the redundant line segment DF resulting from the merging is deleted. The repaired geometric model is as follows. Figure 7 As shown in the diagram on the right.

[0119] Step S2032: Distance repair when the distance between a point and a line is less than the second distance threshold.

[0120] Step S2032A: Draw a first auxiliary line perpendicular to the line through the point to be repaired. When the point and the line are in the same area, move the point or line along the first auxiliary line until the distance between them is greater than or equal to the second distance threshold.

[0121] For example, Figure 8 This is one of the point and line distance repair process diagrams according to an embodiment of the present invention, such as... Figure 8As shown, the perpendicular distance between line segment AE and point C within the region is less than the second distance threshold. An auxiliary line l perpendicular to AE is drawn through point C, and point C is moved away from AE along this auxiliary line until its distance from AE is greater than or equal to the second distance threshold. The repaired geometric model is as follows. Figure 8 As shown in the diagram on the right.

[0122] Step S2032B: When the point and the line are in different areas, move the point or line along the direction of the first auxiliary line until they merge.

[0123] For example, Figure 9 This is a second diagram illustrating the point-to-line distance repair process according to an embodiment of the present invention, as shown below. Figure 9 As shown, the perpendicular distance between line segment CB in region a and point F in region b is less than the second distance threshold. An auxiliary line l perpendicular to CB is drawn through point F, and point F is moved onto line segment CB along the direction of l. The repaired geometric model is as follows. Figure 9 As shown in the diagram on the right.

[0124] Step S204: When the included angle between two line segments is less than the second included angle threshold, under the condition that the second included angle threshold, the preset length threshold and the triangle side angle relationship are satisfied, the two line segments forming the included angle are cut off by the second auxiliary line to form a new line segment and included angle, and the original included angle less than the second included angle threshold and the line segments connected to the included angle are deleted.

[0125] For example, Figure 10 This is a diagram illustrating the process of repairing included angles within a surface region according to an embodiment of the present invention, as shown below. Figure 10 As shown, the angle α formed by line segment BC and line segment CA within the region is less than the second included angle threshold. By introducing an auxiliary line l that meets the preset conditions, line segments BC and AC are cut at points D and E respectively, forming new line segments BD, DE, and AE. These new line segments must meet the preset length threshold, and both included angles β and γ must meet the second included angle threshold requirement. Subsequently, the original included angle α and the connected line segments DC and EC are deleted. The repaired geometric model is as follows. Figure 10 As shown in the diagram on the right.

[0126] Figure 11 This is a diagram illustrating the process of repairing the angle between surfaces according to an embodiment of the present invention, as shown below. Figure 11 As shown, the angle α formed by line segment GC in region a and line segment GA in region b is less than the second included angle threshold. By introducing an auxiliary line l that meets the preset conditions, line segments GC and GA are cut at points H and J respectively. The newly formed line segments HC, AJ, and JH must meet the preset length threshold, and the included angles β and γ must both meet the second included angle threshold requirement. Then, the original included angle α and the connected line segments HG and JG are deleted. The repaired geometric model is as follows. Figure 11 As shown in the diagram on the right.

[0127] The above repair process ensures the compliance of geometric relationships between and within regions, while improving the overall topological consistency and geometric accuracy of the model, providing qualified geometric input for subsequent simulation analysis or manufacturing processes. Through a closed-loop feedback mechanism, the system automatically verifies the repair results after each step, ensuring that no new defective structures are introduced, and can dynamically adjust the repair strategy according to actual needs, thus solving the problems of repair efficiency and success rate.

[0128] Step S205: When there are multiple geometric relationships that need to be repaired within the surface, process them in the order of surface repair, line segment repair, distance repair, and angle repair, and build a closed-loop feedback system to ensure that the model status is automatically detected after each repair and the parameters are adjusted or the strategy is switched in time.

[0129] For repairing geometric relationships of the same type, following the principle of repairing the interior of a region first, then the regions between them, the process begins by calculating the distance from the origin to each point to be repaired (points with unbalanced in-degree for region non-closure repair, intersection points for region intersection repair, endpoints for line segment repair, points to be repaired for distance repair, and vertices of included angle repair). The minimum distance is taken as the starting point, and repairs are performed sequentially in a clockwise direction. In region repair, non-closure repair is performed first, followed by intersection repair; in distance repair, point-to-point distance repair is performed first, followed by point-to-line distance repair. This repair order effectively reduces conflicts and redundant interventions between different repair operations, ensuring the systematic nature and stability of the processing flow. Through unified priority rules and spatial traversal strategies, the model maintains high robustness in repairing complex and varied geometric conditions, while simultaneously improving automation and computational efficiency. This provides reliable technical support for intelligent preprocessing of large-scale engineering drawings and solves the problem of defects being difficult to detect manually.

[0130] For example, Figure 12 These are diagrams illustrating various geometric repair processes within a surface region according to embodiments of the present invention, such as... Figure 12 As shown, points M and L, C and D, and I and H within the region have distances less than the first distance threshold, requiring repair at three points. The minimum distance between the point to be repaired and the origin O is calculated as point M. Starting from M, repairs are performed sequentially in a clockwise direction for points M and L, C and D, and I and H. The repair process generates the following... Figure 12 The second to fourth images.

[0131] Figure 13 This is one of the diagrams illustrating various geometric repair processes between surface regions according to an embodiment of the present invention. For example... Figure 13As shown, there are three regions a, b, and c in the computational domain. The distance between points A and B in region a is less than the first distance threshold, the distance between points F and G in region b is less than the first distance threshold, the distance between point C in region a and point D in region c is less than the first distance threshold, the distance between point N in region a and point M in region c is less than the first distance threshold, and the distance between point J in region b and point K in region c is less than the first distance threshold.

[0132] First, the point-to-point distances within the region are repaired, and the result is as follows. Figure 13 The second image shows the process of repairing the distances between points in different regions. Based on the distance of the point to be repaired from the origin, the repair order is NM, CD, and KJ. Since CN is parallel to DM, a moving point method is used to repair NM and CD simultaneously. The repaired result is shown below. Figure 13 As shown in the third image; finally, KJ is repaired, and the repaired version looks like... Figure 13 As shown in the fourth picture.

[0133] Figure 14 This is a second diagram illustrating various geometric repair processes between surface regions according to an embodiment of the present invention. For example... Figure 14 As shown, the distance between point E in region a and point C in region b is less than the first distance threshold, and the angle α between line segment DE in region a and line segment DC in region b is less than the second angle threshold.

[0134] First, the distance between E and C is repaired using a moving point method. After repair, as shown... Figure 14 As shown in the middle image, the included angle α is then repaired, and the result is as follows. Figure 14 As shown in the diagram on the right.

[0135] Step S206: Check the repair quality of the geometric model item by item. If the coordinate information of the target graphic and the geometric parameters of the geometric model do not meet the preset conditions, adjust the repair threshold or iteration parameters to perform iterative repair until the geometric model meets the preset conditions.

[0136] It should be noted that although Example 1 involves processing a two-dimensional model, it serves as the foundation for forming a three-dimensional model. After the two-dimensional model is formed, a three-dimensional model can be generated through stretching, rotation, and other methods. In other words, the quality of the two-dimensional model processing directly affects the geometric accuracy and simulation reliability of the three-dimensional model. It can reduce the number of defects in the generated three-dimensional model, improve the modeling efficiency and simulation stability, especially in complex industrial scenarios, significantly reducing mesh distortion and computational divergence caused by geometric flaws. Through the technical solution of this invention, automated and batch repair is achieved, greatly improving the efficiency of model preprocessing.

[0137] Example 2

[0138] Example 2 addresses the repair of 3D geometric models. Similar to Example 1, it employs a method to delete irrelevant geometry, diagnose and repair the geometric model, and perform item-by-item checks on the repair quality until preset conditions are met. Figure 26 As shown. The repair of the 3D model includes:

[0139] Step S300: Diagnose and address the main problems affecting the number and quality of meshes in the later stages, such as sharp corners, small gaps, face-to-face intersections, small gaps between faces, and volume-to-volume intersections in the 3D model.

[0140] Step S301: When the length of a line segment is less than a preset length threshold, it is defined as a short line. When the coordinates of the short line are located on or outside the outer contour line of the 3D model, the short line is deleted. If the line segment of the outer contour line is missing after deleting the short line and a surface cannot be generated, surface non-closure repair is performed. When the coordinates of the short line are located inside the outer contour line of the 3D model, the surface containing the short line is diagnosed and repaired between surfaces.

[0141] In practical applications, the coordinate information of the outer contour line of the 3D model is first extracted. If the coordinates of the short line part are on or outside the outer contour line, the short line can be directly deleted. If the outer contour line is missing after deleting the short line and a surface cannot be generated, the surface region non-closed method as in Example 1 can be used for processing. If the coordinates of the short line part are inside the outer contour line, the surface containing the short line is automatically identified and filtered to perform diagnosis and processing between the surfaces of the 3D model.

[0142] Step S302: When the distance between two faces is less than the preset face distance threshold, the smaller face is moved along the preset direction to merge with the other face to form a coplanar surface. The preset direction refers to the distribution direction from one face to another.

[0143] In practical applications, the smaller face can refer to the face with the smaller area among two faces. The smaller face is filled or cut along a preset direction and merged with the larger face, thereby eliminating the geometric defects caused by the small distance between the faces.

[0144] For example, Figure 15 This is a diagram illustrating the process of repairing the distance between surfaces according to an embodiment of the present invention. Figure 15 As shown, if the minimum distance h between surfaces F1 and F2 is less than a preset surface spacing threshold, a filling method is used. This involves moving the smaller surface F1 along a preset direction to fill the affected area and merging it with the previous surface F2. The repaired 3D model is shown below. Figure 15 As shown in the diagram on the right.

[0145] Step S303: Processing of two intersecting surfaces with an included angle less than the third included angle threshold.

[0146] Step S3031: When two faces intersect and the included angle is less than the third included angle threshold, and there is a gap between the two faces, draw the angle bisector of the included angle of the two faces and a third auxiliary line perpendicular to the angle bisector. The two ends of the third auxiliary line intersect the two faces respectively and the length is greater than or equal to the preset length threshold. When the two faces have the same height, generate an auxiliary surface with the intersection line of the third auxiliary line and the two intersecting faces and fill it to the included angle. The filled area is merged with the original 3D model.

[0147] In practical applications, if faces intersect and the angle between them is less than the third angle threshold, auxiliary lines and auxiliary faces are added for filling or cutting. If there is a gap between two faces, the coordinates of their endpoints are used to determine if their heights are the same. If they are the same, an auxiliary line is generated using the midline of the angle between the two faces. The auxiliary line is perpendicular to the midline and its length is greater than a preset length threshold. An auxiliary face is generated using the auxiliary line and the intersection line of the two intersecting faces and filled to the bottom. The filled area is then merged with the original 3D geometry. After processing one area, similar problems in other areas of the entire geometry are automatically processed.

[0148] Specifically Figure 16 This is one of the process diagrams illustrating the repair of the angle between surfaces according to an embodiment of the present invention. For example... Figure 16 As shown, the system first determines whether the heights of Face1 and Face2 are consistent by using the endpoint coordinates of the two faces. If the heights of Face1 and Face2 are consistent and there is a gap between the two faces, the included angle θ between the two faces is less than a third included angle threshold. An auxiliary line Lf is generated using the angle bisector Lz of the included angle between the two faces. The auxiliary line Lf is perpendicular to Lz and its length is greater than a preset length threshold. An auxiliary face Ff is generated using the intersection line of the auxiliary line Lf and the two intersecting faces and filled to the bottom. The filled area is merged with the original 3D geometry. After processing one area, the system automatically processes similar problems in other areas of the entire geometry.

[0149] Step S3032: When two faces intersect and the included angle is less than the third included angle threshold, and there is a gap between the two faces, draw the angle bisector of the included angle of the two faces and a third auxiliary line perpendicular to the angle bisector. The two ends of the third auxiliary line intersect the two faces respectively and the length is greater than or equal to the preset length threshold. When the heights of the two faces are inconsistent, generate an auxiliary face on the lower face of the two faces with the third auxiliary line and the intersection line of the two intersecting faces and fill it to the included angle. The filled area is merged with the original 3D model.

[0150] For example, Figure 17 This is the second diagram illustrating the process of repairing the angle between surfaces according to an embodiment of the present invention. Figure 17As shown, the two faces, Face1 and Face2, have different heights, with Face2 being lower than Face1. A third auxiliary line, Lf, is generated using the angle bisector Lz of the angle between the two faces. The third auxiliary line Lf is perpendicular to Lz and its length is greater than or equal to a preset length threshold. On the lower face, Face2, an auxiliary face Ff is generated using the intersection of the third auxiliary line Lf and the intersection line of the two intersecting faces and is filled to the bottom. The filled area is merged with the original 3D geometry. After processing one area, the system automatically processes similar problems in other areas of the entire geometry.

[0151] Step S3033: When two faces intersect and the included angle is less than the third included angle threshold, and there is a solid between the two faces, draw the angle bisector of the included angle of the two faces and a third auxiliary line perpendicular to the angle bisector. The two ends of the third auxiliary line intersect the two faces respectively and the length is greater than or equal to the preset length threshold. Generate an auxiliary surface with the intersection of the third auxiliary line and the intersection line of the two intersecting faces, and cut and delete the included angle part of the solid along the direction perpendicular to the auxiliary surface.

[0152] For example, Figure 18 This is the third diagram illustrating the process of repairing the angle between surfaces according to an embodiment of the present invention. Figure 18 As shown, the angle θ between two faces, Face1 and Face2, is less than the third angle threshold, and there is a solid between the two faces. The angle bisector Lz of the angle between the two faces is used to generate the third auxiliary line Lf. The third auxiliary line Lf is perpendicular to Lz and its length is greater than or equal to the preset length threshold. The intersection line of the third auxiliary line Lf and the two intersecting faces is used to generate the auxiliary face Ff. The small angle portion of the solid is cut and deleted along the direction perpendicular to the auxiliary face.

[0153] Step S304: Geometric processing of intersecting and embedding volumes.

[0154] Based on the 3D coordinate information of the geometric model, the intersecting situation of the bodies is diagnosed and analyzed. If the bodies intersect and are embedded, there are two processing methods depending on the airflow organization simulation requirements. One method is to use the combination method to select the target body object and automatically merge it. After merging, the two bodies form a 3D geometric model. The other method is to identify the lines, surfaces and volumes of the overlapping geometry, use the intersection surface of the two bodies as the dividing surface to divide the two entities, and automatically delete the newly formed overlapping part of the entity after the division.

[0155] Step S3041: When bodies intersect and embed, use the combination method to merge the bodies to form a new body.

[0156] For example, Figure 19 This is one of the body-to-body intersection repair process diagrams according to an embodiment of the present invention, such as... Figure 19 As shown, Body1 and Body2 intersect and are embedded. Using a combination method, the target objects Body1 and Body2 are selected and merged. After merging, a new body is formed, as shown below. Figure 19 As shown in the diagram on the right.

[0157] Step S3042: When two bodies intersect and are embedded, the intersecting surface of the two bodies is used as the dividing surface to divide them into three new bodies. The embedded parts of the two bodies are deleted and the newly formed bodies are retained.

[0158] For example, Figure 20 This is the second diagram illustrating the body-to-body intersection repair process according to an embodiment of the present invention. Figure 20 As shown, Body1 and Body2 intersect and are embedded. The system identifies the lines, surfaces, and volumes of the overlapping geometry. The intersection face (Face-jiao) of the two bodies is used as the dividing plane to separate Body1 and Body2. After separation, three entities are formed: Body1, Body2-1, and the overlapping part, Body2-2. The newly formed overlapping part, Body2-2, is automatically deleted, retaining Body1 and Body2-1. The processed 3D model is shown below. Figure 20 As shown in the diagram on the right.

[0159] Example 3

[0160] Based on Embodiment 1 and / or Embodiment 2, the geometric model processing method of this embodiment is specifically used for processing complex models of airflow organization simulation.

[0161] Step S400: The geometric model processing methods of Embodiment 1 and Embodiment 2 are comprehensively applied to process complex three-dimensional models such as process equipment, electromechanical, and civil engineering systems.

[0162] Step S401: Processing the three-dimensional model of the process equipment.

[0163] Step S4011: Based on the coordinate information of the short line and the coordinate information of the outline of the 3D model, if there is no line segment outside the outline, determine whether the length of the line segment in the model is less than the preset length threshold. If it is less than the preset length threshold, automatically identify and filter the face containing the short line, and perform diagnosis and processing between the faces.

[0164] Step S4012 Figure 21A This is one of the diagrams illustrating the complex model repair process according to an embodiment of the present invention. For example... Figure 21A As shown, if the distance between surfaces within the selected area is less than the preset surface spacing threshold (the preset surface spacing threshold can be adjusted according to the area, complexity, and other requirements of the airflow simulation area), the smaller surface moves along the preset direction (the distribution direction from one surface to another) to fill or cut the part and merge with another surface.

[0165] Specifically, based on the coordinate information, if the smaller face is a concave face B10 or B30, the filling method is used; if the smaller face is a convex face B40 or B60, the cutting method is used. If the two faces B20 and B50 are the same size, either face can be selected, and the selected face is filled along the preset direction and merged with the other face.

[0166] Step S4013: Perform a face-to-face angle diagnosis.

[0167] If the angle between two faces is less than the third angle threshold, such as Figure 21B The B100 area in the middle, Figure 21B This is the second diagram of the complex model repair process according to an embodiment of the present invention. The angle processing method in step S303 is used to perform cutting processing using auxiliary lines and auxiliary surfaces.

[0168] When the arc angle of a curve on a 3D model is equal to 90° and the arc radius is less than a preset radius threshold, the area is determined to be a rounded surface. Figure 21B The area within the B200 box is shown. For this type of rounded corner surface, the two endpoints of the curve at its end are taken as the starting points of two straight lines. These two lines are extended in a direction perpendicular to the curve and intersect to form a third point. The two endpoints of the curve and this third point form a triangular auxiliary surface. This auxiliary surface fills along the thickness direction of the solid containing the surface and merges with the original solid (forming the right-angled side of the solid). The processed model is shown below. Figure 21D As shown, Figure 21D This is the fourth diagram of the complex model repair process according to an embodiment of the present invention.

[0169] Step S4014: After completing the surface-to-surface processing, perform volume-to-volume diagnostic analysis.

[0170] Figure 21C This is the third diagram illustrating the complex model repair process according to an embodiment of the present invention. Figure 21C As shown, firstly, the points, lines, and surfaces contained in each entity are analyzed based on the 3D coordinate information. If the entity contains curves or surfaces, they are identified based on the curve's arc angle and radius. If a surface is composed of two curves with an arc angle of 180°, or if a curve is composed of a single curve with an arc angle of 360°, and the curve's arc radius is less than a preset radius threshold, then... Figure 21C If Body10 is selected, then that part of the entity will be deleted.

[0171] If no entities as described above exist, further diagnosis is needed to determine whether there are intersections or embeddings between the entities. Figure 21CIf Body20 has intersecting entities, then according to the needs of airflow organization simulation, the two intersecting entities can be merged or the intersecting surfaces can be used to segment and delete the embedded entities. This process equipment model uses entity merging. The processed model is as follows: Figure 21D As shown.

[0172] Step S402: Three-dimensional geometry processing of the electromechanical system.

[0173] Taking the pipe model in an electromechanical system as an example, Figure 22A This is one of the pipeline model repair process diagrams according to an embodiment of the present invention. For example... Figure 22A As shown, the piping system includes pipe G-10, fitting G-20, and pipe accessories G-30. First, line segment diagnosis is performed. If there are no line segments outside the model outline, it is automatically determined whether the length of the line segment or the radius of the circle in the model is less than the preset length threshold. If it is less than the preset length threshold, the face containing the short line is automatically identified and filtered, and the diagnosis and processing between the faces are performed.

[0174] Continue as Figure 22A As shown, pipe G-10 and fitting G-20 are usually connected by pipe accessory G-30. If the distance between the inner and outer surfaces of pipe accessory G-30 is less than the preset surface distance threshold, a circular surface is generated according to the circular curve on one side of the inner curved surface of pipe accessory G-30. The circular surface is filled in the extension direction of pipe accessory G-30 to form a cylinder. The diameter of the cylinder is the same as that of pipe G-10 and fitting G-20. Then pipe accessory G-30 is deleted.

[0175] Subsequently, the method in step S304 is used to process the entities, and the model after processing without merging entities is as follows: Figure 22B As shown, the processing model after merging entities is as follows: Figure 22C As shown, Figure 22B This is the second diagram of the pipeline model repair process according to an embodiment of the present invention; Figure 22C This is the third diagram of the pipeline model repair process according to an embodiment of the present invention.

[0176] Step S403: Three-dimensional geometric processing of the civil engineering system.

[0177] Figure 23 This is a diagram illustrating the civil engineering model repair process according to an embodiment of the present invention. Figure 23 As shown, the civil engineering system takes beam and column models as an example. For horizontal beams L10, vertical beams L20, and inclined beams L30, line segment diagnosis is performed first. If there are no line segments outside the model, it automatically determines whether the length of the line segment or the radius of the circle in the model is less than the preset length threshold. If it is less, it automatically identifies and filters the face containing the short line, and performs diagnosis and processing between the faces.

[0178] The beams are H-beams, such as Figure 23 As shown in the upper right figure, the distance between faces within the selected area is less than the preset face spacing threshold. A filling method is used, based on the model's 3D coordinate information, with the maximum and minimum values ​​in the X, Y, and Z directions serving as boundary points. These boundary points are then used as the endpoints of the hexahedron for filling. After all beams are filled... Figure 23 As shown in the lower right image.

[0179] Then, after the beam is filled, the surface-to-surface diagnostic analysis in the model is carried out. Surfaces in the model whose spacing between surfaces is less than the preset surface spacing threshold are repaired according to the surface-to-surface processing methods in steps S302 and S303.

[0180] Next, the method in step S304 is used to process the entities, and the model after merging the entities is as follows: Figure 23 As shown in the lower left image.

[0181] Step S404, as follows Figure 26 As shown, the repair quality of the geometric model is checked item by item. If the coordinate information of the target graphic and the geometric parameters of the geometric model do not meet the preset conditions, the repair threshold or iteration parameters are adjusted to carry out iterative repair until the geometric model meets the preset conditions.

[0182] Step S405: Using airflow organization simulation software, the model that meets the preset conditions for geometric repair is meshed. Geometric repair threshold parameters or iteration parameters are set according to the specific model mesh quality to meet the high quality requirements of the model mesh.

[0183] Based on actual simulation verification, the geometric model processing method of this invention can effectively improve the accuracy and efficiency of cleanroom airflow organization simulation, and solve the problems of mesh distortion and calculation errors caused by geometric model defects. Actual project verification shows that some equipment models contain various small connectors, tiny holes, and machined chamfers, etc. While these have negligible impact on the flow field for airflow simulation in large spaces, they severely affect the mesh generation quality, making simulation calculations impossible.

[0184] Furthermore, in real-world projects, human error has led to discrepancies of up to 0.001mm between the two endpoints of a line segment in the drawing. This results in highly distorted and substandard meshes during the later stages of 3D modeling, rendering calculations impossible. Manual inspection is often insufficient to detect these issues, and remodeling is costly. This invention, through an automated diagnosis and repair mechanism, effectively identifies and addresses minute redundant features and topological errors in the geometric model. While preserving key structural features, it significantly improves the model's quality and reliability, achieving efficient and stable preprocessing for airflow organization simulation. This provides a reliable foundation for digital simulation in complex industrial scenarios and solves the problem of poor mesh quality or meshing failure in later simulation stages. This method is not only applicable to the electronics and information field but can also be extended to simulation fields in high-precision manufacturing, such as aerospace, biopharmaceuticals, and advanced laser scientific facilities. It significantly shortens the preprocessing cycle, reduces reliance on modeler experience, and improves overall simulation efficiency, demonstrating broad application prospects in the industrial digitalization process.

[0185] Those skilled in the art should understand that the above embodiments are merely for illustrating the present invention and are not intended to limit the scope of the invention. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present invention.

Claims

1. A geometric model processing method for airflow organization simulation, characterized in that, include: Based on the feature information of the geometric model, the target graphics and information are automatically filtered and retained, while other irrelevant geometry is deleted. When the geometric model is a two-dimensional model, the two-dimensional model is repaired by surface repair; when the surface is not closed, if there is only one pair of unbalanced points in the surface, the endpoints are merged and connecting segments are added to repair the surface; if there are multiple pairs of unbalanced points in the surface, the principle of minimum chain length is used, and the nearest paired vertex is found for each vertex in order of vertex distance from the origin from near to far to repair the surface. When a region is self-intersecting, identify the self-intersecting line segments within the region and divide them at the intersection points to form sub-segments, then extract simple closed loops to repair the region. When regions intersect, if there are collinear regions, merge the regions to repair them; if there are regions sharing a common area, calculate the intersection area between the regions and merge the intersection area into either of the two intersecting regions, or merge the two intersecting regions as a whole. When the angle between the line segment and the horizontal or vertical direction is less than the first angle threshold, fix the endpoint of the line segment that is closer to the origin of the coordinates, and move the other endpoint until the line segment is horizontal or vertical. When the difference between the included angle of the two line segments and 90° is less than the first included angle threshold, fix one of the two line segments and move the endpoint of the other line segment until the two line segments are perpendicular. When there are multiple approximately parallel line segments within the same surface region, select multiple line segments whose slope difference is less than a preset slope difference threshold, and use the average slope of the multiple line segments as the final repair value. When the distance between two points is less than a first distance threshold, the midpoint between the two points, or the intersection of the extensions of the line segments containing the two points, is used as the merging point; or... Keeping other points fixed, move two points or one of them along the extension of the line between them; or keep the slope of the line segment containing the two points fixed, move the two points or one of them parallel to each other until the distance between the two points is greater than or equal to a first distance threshold; or... When there is no wireless segment connection between two points in the same area, the midpoint between the two points or one of the points is used as the merging point, and the redundant line segments formed by the merging are deleted after merging. When the included angle between two line segments is less than the second included angle threshold, under the condition that the second included angle threshold, the preset length threshold and the triangle side angle relationship are satisfied, the two line segments forming the included angle are cut off by the second auxiliary line to form a new line segment and included angle, and the original included angle less than the second included angle threshold and the line segments connected to the included angle are deleted; when there are multiple geometric relationships to be repaired within the surface, repair is performed in the order of surface repair, line segment repair, distance repair and included angle repair. The quality of the repair of the geometric model is checked item by item. If the coordinate information of the target graphic and the geometric parameters of the geometric model do not meet the preset conditions, the repair threshold or iteration parameters are adjusted to carry out iterative repair until the geometric model meets the preset conditions.

2. The geometric model processing method according to claim 1, characterized in that, The merging of endpoints and the addition of connecting segments to repair the region include: Keeping the slope of the line segment containing the in-degree imbalance point unchanged, calculate the coordinates of the intersection point of the two line segments based on the coordinates of the in-degree imbalance point and the slope of the line segment. Combine a pair of in-degree imbalance points at the intersection point of the two line segments and construct a line segment to perform region closure repair. When two line segments have no intersection in the direction of the imbalance point or the intersection point is outside the boundary region, the supplementary line segment connects a pair of in-degree imbalance points to perform surface closure repair; if the length of the supplementary line segment is less than the preset length threshold, one of the pair of in-degree imbalance points is fixed and the two points are merged.

3. The geometric model processing method according to claim 2, characterized in that, When the distance between a point and a line is less than the second distance threshold, draw a first auxiliary line perpendicular to the line through the point to be repaired. When the point and the line are in the same area, move the point or line along the first auxiliary line until the distance between them is greater than or equal to the second distance threshold. When a point and a line are in different areas, move the point or line along the direction of the first auxiliary line until they merge.

4. The geometric model processing method according to claim 1, characterized in that, The geometric model further includes a three-dimensional model, and the method further includes: When the length of a line segment is less than a preset length threshold, it is defined as a short line. When the coordinates of the short line are located on or outside the outer contour line of the 3D model, the short line is deleted. If the line segments of the outer contour line are missing after the short line is deleted and a surface cannot be generated, surface non-closure repair is performed. When the coordinates of the short line are located inside the outer contour of the 3D model, the surfaces containing the short line are repaired between each other.

5. The geometric model processing method according to claim 4, characterized in that, Also includes: When the distance between two faces is less than a preset face distance threshold, the smaller face is moved along a preset direction to merge with the other face to form a co-surface. The preset direction refers to the distribution direction from one face to another.

6. The geometric model processing method according to claim 5, characterized in that, Also includes: When two faces intersect and the included angle is less than the third included angle threshold, and there is a gap between the two faces, draw the angle bisector of the included angle between the two faces and a third auxiliary line perpendicular to the angle bisector. The two ends of the third auxiliary line intersect the two faces respectively and the length is greater than or equal to the preset length threshold. When the two faces have the same height, an auxiliary face is generated by the third auxiliary line and the intersection line of the two intersecting faces and filled to the included angle. The filled area is merged with the original 3D model. When the heights of the two faces are not the same, an auxiliary face is generated on the lower face using the third auxiliary line and the intersection line of the two intersecting faces, and filled to the included angle. The filled area is merged with the original 3D model. When two faces intersect and the included angle is less than the third included angle threshold, and there is a solid between the two faces, draw the angle bisector of the included angle between the two faces and a third auxiliary line perpendicular to the angle bisector. The two ends of the third auxiliary line intersect the two faces respectively and the length is greater than or equal to the preset length threshold. Generate an auxiliary surface with the intersection of the third auxiliary line and the intersection line of the two intersecting faces. Cut and delete the included angle portion of the solid along the direction perpendicular to the auxiliary surface.

7. The geometric model processing method according to claim 6, characterized in that, Also includes: When volumes intersect and embed, a combination method is used to merge the volumes into a new volume; or... After dividing the two bodies using their intersecting surfaces as dividing planes, three new bodies are formed. The embedded parts of the two bodies are deleted from the newly formed bodies, and the other two newly formed bodies are retained.

Images