Design method of thrust chamber with an inclined helical channel

Abstract

This application belongs to the field of liquid rocket engine thrust chamber design, and relates to a design method for a thrust chamber constant-angle helical channel. The method includes: obtaining the helical inclination angle, initial coordinates of the helical line, and generatrix data of the thrust chamber; establishing a three-dimensional coordinate system and determining the solution accuracy; obtaining several thrust chamber micro-elements based on the initial coordinates of the helical line and the solution accuracy; using the initial coordinates of the helical line as the starting coordinates of the first thrust chamber micro-element, and solving for the ending coordinates of the first thrust chamber micro-element based on the helical inclination angle; using the ending coordinates of the first thrust chamber micro-element as the starting coordinates of adjacent thrust chamber micro-elements, and solving for the ending coordinates of adjacent thrust chamber micro-elements; until the starting and ending coordinates of all thrust chamber micro-elements are obtained; and designing the constant-angle helical channel of the thrust chamber based on the initial coordinates of the helical line and the ending coordinates of all thrust chamber micro-elements. This method enables a simple and rapid design of the thrust chamber constant-angle helical channel.

Description

Technical Field

[0001] This application relates to the field of liquid rocket engine thrust chamber design technology, and in particular to a design method for a thrust chamber with an equal-angle helical channel. Background Technology

[0002] Currently, regenerative cooling is widely used in high-thrust liquid rocket engines. Regenerative cooling refers to the process where the coolant (usually carried fuel or oxidizer) absorbs energy from the inner walls of the cooling channels after flowing through the collection chamber and cooling channels, and then is injected into the combustion chamber, achieving energy "regeneration." Generally, there are two main types of thrust chamber channels using regenerative cooling: straight channels and spiral channels. While straight channels have a simpler structure, their cooling effect is inferior to spiral channels, and they are generally used when the coolant flow rate is high. For situations with lower coolant flow rates, spiral channels are typically used to improve the cooling effect.

[0003] An equal-angle spiral, also known as a slanted course or slanted driving line. There are currently two methods for solving equal-angle spiral channels:

[0004] (1) The most direct method is to solve the analytical equation of the helical channel and then process it. However, since the thrust chamber generatrix is ​​generally quite complex, or even does not have an analytical equation, it is generally difficult to solve the analytical equation of the helical line.

[0005] (2) Given a known three-dimensional model of the thrust chamber, 3D printing technology can accurately manufacture the engine's thrust chamber. However, this technology can only be realized if we have already established a three-dimensional model of the thrust chamber. For nozzles with arbitrary generatrices, a three-dimensional model of an equal-angle helical channel must be established in order to build a thrust chamber model with cooling channels. However, the coordinates of the helical channels on the surface of an arbitrary generatrice gyroscope are difficult to determine. Summary of the Invention

[0006] Therefore, it is necessary to provide a design method for a thrust chamber constant-angle helical channel to address the above-mentioned technical problems, which can simply and quickly design the thrust chamber constant-angle helical channel.

[0007] The design method for the constant-angle helical channel of the thrust chamber includes:

[0008] Obtain the helix parameters and generatrix data of the thrust chamber; the helix parameters include: helix inclination angle and helix initial coordinates;

[0009] Establish a three-dimensional coordinate system, and determine the solution accuracy based on the three-dimensional coordinate system and the generatrix data;

[0010] Based on the initial coordinates of the helix and the solution accuracy, several thrust chamber micro-elements are obtained;

[0011] Using the initial coordinates of the spiral as the starting coordinates of the first thrust chamber micro-element, the ending coordinates of the first thrust chamber micro-element are solved according to the inclination angle of the spiral; using the ending coordinates of the first thrust chamber micro-element as the starting coordinates of the adjacent thrust chamber micro-element, the ending coordinates of the adjacent thrust chamber micro-element are solved; until the starting coordinates and ending coordinates of all thrust chamber micro-elements are obtained.

[0012] Based on the initial coordinates of the helix and the endpoint coordinates of all thrust chamber micro-elements, the constant-angle helical channel of the thrust chamber is designed.

[0013] In one embodiment, based on the initial coordinates of the helix and the solution accuracy, a plurality of thrust chamber micro-elements are obtained, including:

[0014] The plane containing the initial coordinates of the spiral is the plane where the thrust chamber outlet is located.

[0015] Using the solution accuracy as the interval, several parallel intermediate planes are set between the plane where the thrust chamber outlet is located and the plane where the thrust chamber inlet is located;

[0016] The infinitesimal element of the thrust chamber, which is cut between any two adjacent planes, is called the thrust chamber element.

[0017] In one embodiment, taking the initial coordinates of the helix as the starting coordinates of the first thrust chamber micro-element, and determining the ending coordinates of the first thrust chamber micro-element based on the helix inclination angle includes:

[0018] The first thrust chamber micro-element is the thrust chamber micro-element intercepted between the plane where the thrust chamber outlet is located and the adjacent intermediate plane; a cylindrical micro-element corresponding to the first thrust chamber micro-element is established with the circular cross-section of the thrust chamber outlet as the base and the solution accuracy as the highest.

[0019] Starting from the initial coordinates of the spiral, draw a first spiral line with an inclination angle equal to the inclination angle of the spiral on the cylindrical micro-element; connect the end point of the first spiral line with the center of the top surface of the cylindrical micro-element to form a first line segment; connect the projection point of the initial coordinates of the spiral on the top surface of the cylindrical micro-element with the center of the top surface of the cylindrical micro-element to form a second line segment.

[0020] Based on the height of the cylindrical micro-element and the inclination angle of the spiral, the included angle between the first line segment and the second line segment is determined.

[0021] Using the initial coordinates of the spiral as the starting coordinates of the first thrust chamber micro-element, the ending coordinates of the first thrust chamber micro-element are calculated based on the starting coordinates of the first thrust chamber micro-element, the ending coordinates of the first spiral, and the included angle.

[0022] In one embodiment, taking the initial coordinates of the spiral as the starting coordinates of the first thrust chamber micro-element, the solution to the ending coordinates of the first thrust chamber micro-element based on the starting coordinates of the first thrust chamber micro-element, the ending coordinates of the first spiral, and the included angle includes:

[0023]

[0024]

[0025] z c =z b =z a +Δz

[0026] Δx=x b -x a =R×(cos(θ+Δθ)-cos(θ))

[0027] Δy=y b -y a =R×(sin(θ+Δθ)-sin(θ))

[0028] Δz=z b -z a

[0029] R1=f(z a )

[0030] R2=f(z c )

[0031] In the formula, (x a ,y a ,z a (x) represents the starting coordinates of the first thrust chamber micro-element. b ,y b ,z b (x) represents the coordinates of the endpoint of the first spiral. c ,y c ,z c R is the coordinate of the endpoint of the first thrust chamber micro-element, R1 is the radius of the bottom surface of the cylindrical micro-element, R2 is the radius of the top surface of the cylindrical micro-element, R is the radius of the bottom cross-section circle R1, Δθ is the angle between the projections of the lines connecting the starting point to the origin and the ending point to the origin on the xOy plane, and θ is the minimum angle of the x-axis rotating counterclockwise around the origin to the point passing through the initial position of the spiral.

[0032] In one embodiment, establishing a three-dimensional coordinate system includes:

[0033] The origin O of the coordinate system is the center of the circular cross-section at the thrust chamber outlet.

[0034] Taking the circular cross-section at the thrust chamber outlet as the xOy plane, any straight line coinciding with the diameter of the circular cross-section is selected in this plane as the x-axis, and the y-axis perpendicular to the x-axis is determined; the positive direction of the z-axis is the straight line perpendicular to the circular cross-section at the thrust chamber outlet, passing through the origin O, and pointing towards the inside of the thrust chamber; the x-axis, y-axis, and z-axis satisfy the right-hand screw rule;

[0035] Based on the above principles, a three-dimensional coordinate system is established.

[0036] In one embodiment, determining the solution accuracy based on the three-dimensional coordinate system and the generatrix data includes:

[0037] Based on the xyz three-dimensional coordinate system, an rz two-dimensional coordinate system is established, and the set of busbar coordinates of the busbar data in the rz two-dimensional coordinate system is obtained;

[0038] The solution accuracy is determined based on the coordinates of two adjacent busbars in the busbar coordinate set.

[0039] In one embodiment, the design of the constant-inclination helical channel of the thrust chamber, based on the initial coordinates of the helix and the endpoint coordinates of all thrust chamber micro-elements, includes:

[0040] Based on the initial coordinates of the helix and the endpoint coordinates of all thrust chamber micro-elements, the line connecting these coordinates forms the constant-angle helical channel of the thrust chamber.

[0041] The aforementioned design method for the thrust chamber's constant-angle helical channel establishes a three-dimensional coordinate system and determines the solution accuracy based on the helical parameters and generatrix data of the thrust chamber. The thrust chamber is divided into several micro-elements. The endpoint coordinates of the helical line within the first micro-element are solved, and the endpoint coordinates of the current micro-element are used as the starting coordinates of the next micro-element. This process is repeated for all micro-elements to obtain the coordinates of the helical line within each micro-element, thus obtaining the trajectory of the helical line and consequently, the constant-angle helical channel. Using this design method for the constant-angle helical line and constant-angle helical channel, the solution accuracy can be determined based on the existing thrust chamber geometry and manufacturing process. By introducing the method of micro-elements and combining it with the mathematical concept of differential limits, the coordinates of the constant-angle helical line can be numerically solved. This allows the curve to be straightened, yielding the trajectory of the helical channel on the thrust chamber wall. This method does not require solving the analytical equations of the helical channel or establishing a three-dimensional model of the constant-angle helical channel; it is ingeniously conceived and highly practical. Attached Figure Description

[0042] Figure 1 This is a flowchart illustrating the design method of the thrust chamber constant-angle spiral channel in one embodiment;

[0043] Figure 2 This is a schematic diagram of the thrust chamber system in one embodiment;

[0044] Figure 3 This is a schematic diagram of the initial position of the spiral in one embodiment;

[0045] Figure 4 This is a schematic diagram of the rz coordinate system in one embodiment;

[0046] Figure 5 This is a schematic diagram of a thrust chamber micro-element in one embodiment;

[0047] Figure 6 This is a schematic diagram showing the detailed geometric features of a thrust chamber micro-element in one embodiment;

[0048] Figure 7 This is a diagram showing the spiral development of the surface of a thrust chamber micro-element in one embodiment;

[0049] Figure 8 This is a top view of a thrust chamber micro-element in one embodiment. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0051] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0052] Furthermore, the use of terms such as "first," "second," etc., in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this application, "multiple sets" means at least two sets, such as two sets, three sets, etc., unless otherwise explicitly specified.

[0053] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0054] Furthermore, the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0055] This application provides a design method for a thrust chamber constant-angle helical channel, such as... Figure 1 As shown, in one embodiment, it includes:

[0056] Step 102: Obtain the helix parameters and generatrix data of the thrust chamber; the helix parameters include: helix inclination angle and helix initial coordinates.

[0057] In this step, the helix angle refers to the angle between the helix and the z-axis.

[0058] The initial coordinates of the helix are the positions of the intersection points of the helix and the thrust chamber outlet cross-section circle.

[0059] The helical parameters also include the number of helices. The number of helices refers to the number of equally spaced helical channels distributed on a thrust chamber of a specific geometry, according to cooling requirements.

[0060] Since the thrust chamber is a rotating body, the geometric characteristics of the thrust chamber can be obtained simply by determining the generatrix data, that is, the geometric characteristics of the generatrix of the thrust chamber.

[0061] Step 104: Establish a three-dimensional coordinate system and determine the solution accuracy based on the three-dimensional coordinate system and the generatrix data.

[0062] Specifically:

[0063] The origin O of the coordinate system is set at the center of the circular cross-section at the thrust chamber outlet. The xOy plane is the circular cross-section at the thrust chamber outlet. A straight line arbitrarily chosen within this plane, coinciding with the diameter of the circular cross-section, is taken as the x-axis (since the thrust chamber is a spun solid). The y-axis is then determined to be perpendicular to the x-axis. The positive direction of the z-axis is defined as a straight line perpendicular to the circular cross-section at the thrust chamber outlet, passing through the origin O, and pointing towards the interior of the thrust chamber. The x, y, and z axes satisfy the right-hand screw rule. Based on these principles, a three-dimensional coordinate system is established.

[0064] Based on the xyz three-dimensional coordinate system, an rz two-dimensional coordinate system is established, and the set of bus coordinates of the bus data in the rz two-dimensional coordinate system is obtained; the solution accuracy is determined based on the coordinates of two adjacent bus in the set of bus coordinates.

[0065] In this step, establishing a coordinate system means creating a coordinate system that facilitates problem-solving based on the geometric characteristics of the object being solved. For the problem of drawing the helix of a liquid rocket engine thrust chamber, a three-dimensional Cartesian coordinate system is established, such as... Figure 2 As shown.

[0066] Assume the initial position of the i-th spiral is P. i Since the thrust chamber wall is symmetrical about the z-axis and the spirals are equidistant, the initial position of the first spiral can be arbitrarily selected on the exit section circle, and then the relative positions of the other initial points can be ensured to be correct.

[0067] For ease of calculation, the initial position P1 of the first helix is ​​chosen as the intersection point (R0,0,0) of the x-axis and the thrust chamber wall. The remaining n-1 points are selected at equal intervals on the circumference of the thrust chamber outlet section, such as... Figure 3 As shown.

[0068] The coordinates of the i-th point can be expressed as:

[0069] P i =(R0×cos(i×Δα),R0×sin(i×Δα))

[0070] In the formula, Δα is the angle between the initial positions of two adjacent helices on the thrust chamber outlet cross section circle, which is the circumferential angle 360° divided by the number of helices.

[0071] The generatrix is ​​the moving line that can form a curved surface through motion. It is necessary to determine the two-dimensional geometric characteristics of the generatrix, that is, the thrust chamber radius corresponding to different z-axis.

[0072] Establish a two-dimensional rz coordinate system, such as Figure 4 As shown. For busbar data, a set of arithmetic z-coordinate arrays and corresponding r-coordinate values ​​need to be input. The minimum value of each element in the z-coordinate array is 0, and the maximum value is the total length of the thrust chamber, meaning it needs to cover the entire thrust chamber length.

[0073] Its mathematical expression is as follows: Assume that the coordinate set of the thrust chamber generatrix in the rz coordinate system is M, where the i-th element is M. i =(r i ,z i If the total length of the thrust chamber is h, then M must satisfy:

[0074] (1)z i+1 -z i =const;

[0075] (2)z min =0,z max =h;

[0076] (3)r i For z = z i The radius of the corresponding thrust chamber is the distance between the generatrix and the z-axis in the z-coordinate.

[0077] After obtaining the information of the thrust chamber generatrix, the difference in the z-axis coordinates is z. i+1 -z i This refers to the accuracy of the solution. Theoretically, the higher the accuracy, the more accurate the spiral solution will be and the smoother the curve will be. However, considering the accuracy of 3D printing and the difficulty of the solution, an accuracy of 1mm is generally considered to meet the accuracy requirements.

[0078] Generally, when the analytical equations of the thrust chamber busbar are known and solvable, the r-coordinate values ​​under different z-coordinates can be directly calculated, with an accuracy of 1 mm. When the analytical equations of the thrust chamber busbar are unknown or unsolvable, a 3D scanner can be used to obtain thrust chamber busbar information with an accuracy of 1 mm. Alternatively, if higher accuracy is required but higher-precision busbar information cannot be obtained, the existing busbar information can be used to fit a function equation of the busbar based on a polynomial fitting function or other fitting functions to obtain higher-precision busbar information. However, this method needs to consider the influence of fitting bias.

[0079] Step 106: Based on the initial coordinates of the helix and the solution accuracy, several thrust chamber micro-elements are obtained.

[0080] Specifically:

[0081] The plane containing the initial coordinates of the spiral is the plane containing the thrust chamber outlet; with the solution accuracy as the interval, several parallel intermediate planes are set between the plane containing the thrust chamber outlet and the plane containing the thrust chamber inlet; the micro-element of the thrust chamber intercepted between any two adjacent planes is the thrust chamber micro-element.

[0082] In this step, the initial point P of the spiral is used. iThe plane perpendicular to the z-axis is the plane containing the lower base. The plane is parallel to the lower base, above it (in the positive z-direction), and at a distance Δh = z from the lower base. i+1 -z i The plane at which the position is located is the plane containing the upper bottom surface. The infinitesimal element of the thrust chamber, obtained by cutting through the two planes, is the thrust chamber element, such as... Figure 5 As shown.

[0083] Step 108: Using the initial coordinates of the helix as the starting coordinates of the first thrust chamber micro-element, solve for the ending coordinates of the first thrust chamber micro-element based on the inclination angle of the helix; using the ending coordinates of the first thrust chamber micro-element as the starting coordinates of the adjacent thrust chamber micro-element, solve for the ending coordinates of the adjacent thrust chamber micro-element; until the starting coordinates and ending coordinates of all thrust chamber micro-elements are obtained.

[0084] Specifically:

[0085] The first thrust chamber micro-element is the thrust chamber micro-element intercepted between the plane where the thrust chamber outlet is located and the adjacent intermediate plane; a cylindrical micro-element corresponding to the first thrust chamber micro-element is established with the circular cross-section of the thrust chamber outlet as the base and the solution accuracy as the highest.

[0086] Starting from the initial coordinates of the spiral, draw a first spiral line with an inclination angle equal to the inclination angle of the spiral on the cylindrical micro-element; connect the end point of the first spiral line with the center of the top surface of the cylindrical micro-element to form a first line segment; connect the projection point of the initial coordinates of the spiral on the top surface of the cylindrical micro-element with the center of the top surface of the cylindrical micro-element to form a second line segment.

[0087] Based on the height of the cylindrical micro-element and the inclination angle of the spiral, the included angle between the first line segment and the second line segment is determined.

[0088] Using the initial coordinates of the spiral as the starting coordinates of the first thrust chamber micro-element, the ending coordinates of the first thrust chamber micro-element are calculated based on the starting coordinates of the first thrust chamber micro-element, the ending coordinates of the first spiral, and the included angle.

[0089] More specifically, such as Figures 6 to 8 As shown, a cylindrical element with a height of Δh is constructed using the circular cross-section of the lower surface of the obtained thrust chamber element as the base.

[0090] Let the initial position of the helix (i.e., the starting coordinates of the first thrust chamber element) be A = (x a ,y a ,z a The termination position of the helix (i.e., the endpoint coordinates of the first thrust chamber element) is C = (x c ,y c ,z cStarting from point A, draw a helix with an inclination angle of α (helix inclination angle) on the cylindrical element. Let the ending position of the helix on the cylindrical element (i.e., the coordinates of the endpoint of the first helix) be B = (x... b ,y b ,z b ).

[0091] Since the inclination angle of the helix on both the thrust chamber micro-element and the cylindrical micro-element is α, it can be assumed that the helix on the surface of the thrust chamber micro-element is obtained by projecting the helix on the surface of the cylindrical micro-element onto the z-axis onto the surface of the thrust chamber. Therefore, points O, C, and B are on a straight line.

[0092] Let R1 be the radius of the lower base cross-section of the cylindrical element (i.e., the radius of the bottom surface of the cylindrical element), and R2 be the radius of the upper base cross-section (i.e., the radius of the top surface of the cylindrical element). Draw AA′ perpendicular to the lower base through point A, intersecting the upper surface of the cylindrical element at point A′. Let ∠A′OB be Δθ, where Δθ is the angle between the projections of the lines connecting the starting point to the origin and the ending point to the origin onto the xOy plane, θ is the minimum angle of the x-axis rotating counterclockwise around the origin to the initial position of the spiral, and the length of the arc A′B is ΔL.

[0093] Solve for Δθ:

[0094]

[0095]

[0096] In the formula, R is taken as the radius R1 of the lower bottom cross-section circle.

[0097] Find the coordinates of point C:

[0098] Δx=x b -x a =R×(cos(θ+Δθ)-cos(θ))

[0099] Δy=y b -y a =R×(sin(θ+Δθ)-sin(θ))

[0100] Δz=z b -z a

[0101]

[0102] Since points O, C, and B lie on a straight line, we obtain the following relationship:

[0103]

[0104]

[0105] z c =z b =z a +Δz

[0106] Where R1 and R2 are functions of z, and different z coordinates correspond to different R values, that is:

[0107] R1=f(z a )

[0108] R2=f(z c )

[0109] In this step, after obtaining the coordinates of point C, which is the endpoint coordinate of the helix in the first thrust chamber micro-element, the endpoint coordinates are set as the starting coordinates for the next solution. That is, the endpoint coordinates of the helix in the next thrust chamber micro-element, which is the adjacent thrust chamber micro-element, are solved until all thrust chamber micro-elements are traversed and the endpoint coordinates of the helix in each thrust chamber micro-element are obtained.

[0110] Step 110: Based on the initial coordinates of the helix and the endpoint coordinates of all thrust chamber micro-elements, design the constant-angle helical channel of the thrust chamber.

[0111] Specifically:

[0112] Based on the initial coordinates of the helix and the endpoint coordinates of all thrust chamber micro-elements, the line connecting these coordinates forms the constant-angle helical channel of the thrust chamber.

[0113] In this step, based on the coordinate information of the helix from the thrust chamber outlet section to the thrust chamber inlet section obtained by the solution, the coordinate set of the helix based on the existing thrust chamber configuration is obtained. Since the helix is ​​decomposed into several parts distributed in different thrust chamber micro-elements and solved one by one, based on the solution accuracy, it can be considered that, under the condition of meeting manufacturing accuracy, the broken line formed by the connection between the initial and final coordinate points of the helix in each micro-element can be approximated as a curve, that is, the connection of the coordinate points is considered to be the helix with an equal inclination angle. Furthermore, based on each initial point, the coordinate set of each helix is ​​obtained iteratively, and the connection of the elements in the coordinate set of each helix can be obtained. The equal inclination angle helical channel of the thrust chamber can be designed based on all coordinate sets.

[0114] Thrust Chamber: The thrust chamber of a liquid rocket engine generally consists of an injector, a combustion chamber, and a nozzle. The injector is the device that injects fuel and oxidizer into the combustion chamber, which is where the oxidizer and fuel mix and burn. The nozzle is the converging and expanding nozzle that can accelerate subsonic gases to supersonic speeds.

[0115] Regenerative cooling: A cooling method for liquid rocket engines. Liquid rocket engines typically carry cryogenic propellants, which are used to cool the thrust chamber walls to maximize energy utilization. Specifically, the cryogenic propellant exchanges heat with the high-temperature exhaust gases through cooling channels on the thrust chamber surface.

[0116] Cooling channels: Channels through which coolant flows on the outer surface of the thrust chamber.

[0117] Equal-angle helix: A helix whose angle with the centerline of the thrust chamber (around which the generatrix rotates) is a constant.

[0118] In this embodiment, the coolant flow channel on the outer surface of the liquid rocket engine thrust chamber is called the cooling channel. When the cooling channel is an equal-angle spiral channel, the trajectory of the equal-angle spiral channel is a number of equal-angle spirals. An equal-angle spiral is a spiral with a fixed angle between the spiral and the center line of the thrust chamber (the generatrix rotates around it).

[0119] The helix on the thrust chamber surface can be considered as a projection of a cylindrical surface onto the thrust chamber surface. Therefore, the endpoint of the cylindrical helix can be projected onto the thrust chamber to obtain the endpoint coordinates of the helix on the thrust chamber. The endpoint coordinates of the helix obtained in this solution are set as the initial coordinates for the next iteration, and this process is repeated iteratively to solve for the coordinate set of the entire helix on the thrust chamber surface. Connecting the points in the obtained coordinate set, and considering the idea of ​​straightening curves into straight lines, the resulting broken line is considered to be the helix we are looking for.

[0120] The aforementioned design method for the thrust chamber's constant-angle helical channel establishes a three-dimensional coordinate system and determines the solution accuracy based on the helical parameters and generatrix data of the thrust chamber. The thrust chamber is divided into several micro-elements. The endpoint coordinates of the helical line within the first micro-element are solved, and the endpoint coordinates of the current micro-element are used as the starting coordinates of the next micro-element. This process is repeated for all micro-elements to obtain the coordinates of the helical line within each micro-element, thus obtaining the trajectory of the helical line and consequently, the constant-angle helical channel. Using this design method for the constant-angle helical line and constant-angle helical channel, the solution accuracy can be determined based on the existing thrust chamber geometry and manufacturing process. By introducing the method of micro-elements and combining it with the mathematical concept of differential limits, the coordinates of the constant-angle helical line can be numerically solved. This allows the curve to be straightened, yielding the trajectory of the helical channel on the thrust chamber wall. This method does not require solving the analytical equations of the helical channel or establishing a three-dimensional model of the constant-angle helical channel; it is ingeniously conceived and highly practical.

[0121] It should be understood that, although Figure 1The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0122] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0123] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A design method for a thrust chamber constant-angle helical channel, characterized in that, include: Obtain the helix parameters and generatrix data of the thrust chamber; the helix parameters include: helix inclination angle and helix initial coordinates; Establish a three-dimensional coordinate system, and determine the solution accuracy based on the three-dimensional coordinate system and the generatrix data; Based on the initial coordinates of the helix and the solution accuracy, several thrust chamber micro-elements are obtained; Using the initial coordinates of the spiral as the starting coordinates of the first thrust chamber micro-element, the ending coordinates of the first thrust chamber micro-element are solved according to the inclination angle of the spiral; using the ending coordinates of the first thrust chamber micro-element as the starting coordinates of the adjacent thrust chamber micro-element, the ending coordinates of the adjacent thrust chamber micro-element are solved; until the starting coordinates and ending coordinates of all thrust chamber micro-elements are obtained. Based on the initial coordinates of the helix and the endpoint coordinates of all thrust chamber micro-elements, the constant-angle helical channel of the thrust chamber is designed. Using the initial coordinates of the helix as the starting coordinates of the first thrust chamber micro-element, and based on the inclination angle of the helix, the ending coordinates of the first thrust chamber micro-element are determined as follows: The first thrust chamber micro-element is the thrust chamber micro-element intercepted between the plane where the thrust chamber outlet is located and the adjacent intermediate plane; a cylindrical micro-element corresponding to the first thrust chamber micro-element is established with the circular cross-section of the thrust chamber outlet as the base and the solution accuracy as the highest. Starting from the initial coordinates of the spiral, draw a first spiral line with an inclination angle equal to the inclination angle of the spiral on the cylindrical micro-element; connect the end point of the first spiral line with the center of the top surface of the cylindrical micro-element to form a first line segment; connect the projection point of the initial coordinates of the spiral on the top surface of the cylindrical micro-element with the center of the top surface of the cylindrical micro-element to form a second line segment. Based on the height of the cylindrical micro-element and the inclination angle of the spiral, the included angle between the first line segment and the second line segment is determined. Using the initial coordinates of the spiral as the starting coordinates of the first thrust chamber micro-element, the ending coordinates of the first thrust chamber micro-element are calculated based on the starting coordinates of the first thrust chamber micro-element, the ending coordinates of the first spiral, and the included angle. Taking the initial coordinates of the spiral as the starting coordinates of the first thrust chamber micro-element, the solution to the ending coordinates of the first thrust chamber micro-element based on the starting coordinates of the first thrust chamber micro-element, the ending coordinates of the first spiral, and the included angle includes: In the formula, The coordinates of the starting point of the first thrust chamber micro-element are given. The coordinates of the endpoint of the first spiral are... Let these be the coordinates of the endpoint of the first thrust chamber micro-element. Let the radius of the base of the cylindrical infinitesimal element be . Let the radius of the top surface of the cylindrical infinitesimal element be . R The value is taken as the radius of the bottom surface cross-section circle. , The lines connecting the starting point to the origin and the ending point to the origin are in The angle between the projections on the plane for The axis rotates counterclockwise around the origin to the minimum angle passing through the initial position point of the helix.

2. The method according to claim 1, characterized in that, Based on the initial coordinates of the helix and the solution accuracy, several thrust chamber micro-elements are obtained, including: The plane containing the initial coordinates of the spiral is the plane where the thrust chamber outlet is located. Using the solution accuracy as the interval, several parallel intermediate planes are set between the plane where the thrust chamber outlet is located and the plane where the thrust chamber inlet is located. The infinitesimal element of the thrust chamber, which is cut between any two adjacent planes, is called the thrust chamber element.

3. The method according to claim 1 or 2, characterized in that, Establishing a three-dimensional coordinate system includes: The origin of the coordinate system is the center of the circular cross-section at the thrust chamber outlet. O point; Taking the circular cross-section of the thrust chamber outlet as xOy A plane, in which any straight line coinciding with the diameter of the cross-section circle is selected. x Axis, and determine with x Axis perpendicular y Axis; with a circular cross-section perpendicular to the thrust chamber outlet, passing through the origin. O Point, and the straight line pointing towards the inside of the thrust chamber is z The positive direction of the axis; x axis, y shaft and z The axis satisfies the right-hand screw rule; Based on the above principles, a three-dimensional coordinate system is established.

4. The method according to claim 3, characterized in that, Determining the solution accuracy based on the three-dimensional coordinate system and the generatrix data includes: according to xyz Establish a three-dimensional coordinate system rz A two-dimensional coordinate system is used to obtain the bus data. rz Generatrix coordinate set in a two-dimensional coordinate system; The solution accuracy is determined based on the coordinates of two adjacent busbars in the busbar coordinate set.

5. The method according to claim 1 or 2, characterized in that, Based on the initial coordinates of the helix and the endpoint coordinates of all thrust chamber micro-elements, the design of the constant-inclination helical channel of the thrust chamber includes: Based on the initial coordinates of the helix and the endpoint coordinates of all thrust chamber micro-elements, the line connecting these coordinates forms the constant-angle helical channel of the thrust chamber.

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