A front edge embedded distributed ducted fan power wing and integrated design optimization method

Abstract

The application discloses a front edge embedded distributed ducted fan power wing and an integrated design optimization method, and belongs to the technical field of aircraft design. The method comprises the following steps: according to the influence range and intensity of the embedded ducted jet on the wing surface flow field, classifying the sections at different positions along the wing span, and establishing a differentiated section deformation strategy; establishing a performance collaborative optimization model of aerodynamic fusion configuration, carrying out integrated iterative design optimization of the ducted propulsion system and the wing aerodynamic shape based on the differentiated section deformation strategy, and obtaining the optimized aerodynamic fusion configuration. The application can fully exploit the beneficial coupling effect between the ducted jet and the wing flow field, improve the overall aerodynamic efficiency of the wing and the comprehensive performance of the propulsion system while taking into account the lift characteristics, drag characteristics and pitching moment characteristics, and provides a new technical approach for the design of distributed electric propulsion aircraft and aerodynamic propulsion integrated aircraft.

Description

Technical Field

[0001] This invention belongs to the field of aircraft design technology, specifically relating to a leading-edge embedded distributed ducted fan powered wing and an integrated design optimization method. Background Technology

[0002] Against the backdrop of the global aviation industry's transformation towards green, electrified, and intelligent technologies, Distributed Electric Propulsion (DEP) technology is widely recognized as a core technology supporting next-generation aircraft design due to its enormous potential in terms of high safety, high efficiency, low noise, and optimized aerodynamic performance. Distributed Electric Ducted Fans (DEDFs), as an efficient implementation of DEP, strategically arrange multiple miniaturized electric ducted fans along wings or other aerodynamic surfaces, bringing new degrees of freedom to aircraft design. Compared to traditional open propellers, ducted fans offer higher static thrust efficiency, better noise suppression characteristics, and greater physical safety. More importantly, when DEDFs are tightly integrated with lifting surfaces such as wings, a strong aerodynamic / propulsion coupling effect is generated between them. This is no longer an interference problem that traditional aircraft design must avoid, but rather a potential advantage that can be actively utilized to improve overall performance. Therefore, it is necessary to develop an integrated design methodology for distributed ducted fan wings.

[0003] Using distributed ducted fans to improve wing aerodynamic characteristics is a current hot technology approach, but most existing technologies use trailing-edge ducted fans to achieve lift enhancement. Furthermore, most designs are direct combinations of the wing and ducted fans without integrated design and optimization.

[0004] Currently, no design can fully leverage the advantages of the coupling effect between wing aerodynamics and ducted propulsion, and there is no suitable integrated optimization method for ducted fans and wings. Therefore, it is necessary to develop a novel integrated design and optimization method for a ducted wing with a leading-edge embedded distributed ducted fan power, which fully utilizes the advantages of aerodynamic / propulsion coupling characteristics. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a leading-edge embedded distributed ducted fan powered wing and an integrated design optimization method, which can effectively solve the above problems.

[0006] The technical solution adopted in this invention is as follows:

[0007] In a first aspect, the present invention provides a leading-edge embedded distributed ducted fan powered wing, comprising a wing and an embedded duct; the wing includes a ducted section wing and outer wing sections arranged along the spanwise direction of the ducted section wing on both the inner and outer sides of the ducted section wing; the embedded ducts are arranged in an array along the spanwise direction of the ducted section wing in the leading-edge region of the ducted section wing, and adjacent embedded ducts are closely spaced without gaps, and the inlet region of each embedded duct is embedded inside the leading edge of the ducted section wing, forming a continuous distributed ducted propulsion system.

[0008] Secondly, the present invention provides an integrated design optimization method for a leading-edge embedded distributed ducted fan powered wing, used for the integrated design optimization of such a wing, the method comprising the following steps:

[0009] Step S1: Establish a parameterized model of the aerodynamic blended configuration including the ducted wing section, the outer wing section, and each embedded duct. The parameterized model includes a parameterized model of the wing composed of the ducted wing section and the outer wing section, and a parameterized model of the ducted propulsion system composed of each embedded duct.

[0010] Step S2: Based on the influence range and intensity of the embedded ducted jet on the wing surface flow field, the cross-sections at different positions along the wing span are classified, and a differentiated cross-section deformation strategy is established:

[0011] For each section located on the outer wing segment, the airfoil shape at the section is kept unchanged to maintain the overall lift distribution characteristics of the wing. For the section located at the center of each embedded duct, a joint parametric deformation strategy is established, and the airfoil geometry parameters of the duct section and the inner wall geometry parameters of the embedded duct are parametrically controlled to achieve coordinated deformation. For the section located at the duct junction where the embedded duct meets the wing, a separate parametric deformation strategy is established, and the airfoil geometry parameters of the duct section are parametrically controlled only at the section.

[0012] Step S3: Establish a performance synergistic optimization model for the aerodynamic blending configuration. Use the ducted section wing airfoil geometry parameters, embedded duct inner wall geometry parameters, and embedded duct fan position parameters as design variables. Use the optimal comprehensive performance of the aerodynamic blending configuration calculated based on the comprehensive evaluation function as the optimization objective. Use the lift coefficient and pitching moment coefficient as optimization constraints. Based on the differentiated cross-section deformation strategy, carry out integrated iterative design optimization of the ducted propulsion system and the wing aerodynamic shape to obtain the optimized aerodynamic blending configuration.

[0013] The leading-edge embedded distributed ducted fan powered wing and integrated design optimization method provided by the present invention have the following advantages: The present invention can fully exploit the beneficial coupling effect between the ducted jet and the wing flow field, and improve the overall aerodynamic efficiency of the wing and the comprehensive performance of the propulsion system while taking into account the lift characteristics, drag characteristics and pitch moment characteristics, providing a new technical approach for the design of distributed electric propulsion aircraft and aerodynamic propulsion integrated aircraft. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 A flowchart illustrating the integrated design optimization method for a leading-edge embedded distributed ducted fan powered wing provided by the present invention;

[0016] Figure 2 A schematic diagram of the overall design of a leading-edge embedded distributed ducted fan powered wing provided in an embodiment of the present invention;

[0017] Figure 3 A schematic diagram of the ducted section wing provided in an embodiment of the present invention;

[0018] Figure 4 This is a schematic diagram of the cross-section at the center of the culvert provided in an embodiment of the present invention;

[0019] Figure 5 This is a schematic diagram of the FFD frame arrangement at the center of the culvert provided in an embodiment of the present invention;

[0020] Figure 6 This is a schematic diagram of the FFD frame arrangement at the culvert intersection provided in an embodiment of the present invention.

[0021] Among them: 1. Duct section wing; 2. One side outer wing section; 3. The other side outer wing section; 4. Embedded duct; 5. Embedded duct inner wall section; 6. Duct section wing airfoil section. Detailed Implementation

[0022] To make the technical problems solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the invention.

[0023] This invention provides a leading-edge embedded distributed ducted fan powered wing, comprising a wing and embedded ducts; the wing is a straight wing, including a ducted section wing and outer wing sections arranged along the spanwise direction of the ducted section wing on both the inner and outer sides of the ducted section wing; the embedded ducts are arranged in an array along the spanwise direction of the ducted section wing in the leading-edge region of the ducted section wing, with adjacent embedded ducts tightly packed without gaps, and the inlet region of each embedded duct is embedded inside the leading edge of the ducted section wing, forming a continuous distributed ducted propulsion system. Please refer to [link to relevant documentation]. Figure 2 and Figure 3 The diagram shows the layout of the ducted wing 1, one outer wing section 2, the other outer wing section 3, and the embedded duct 4.

[0024] The lower surface of the lip of the embedded duct is continuously fused with the upper surface of the leading edge of the duct section wing.

[0025] In this invention, the leading edge upper surface of the ducted section wing is partially fused and modified according to the shape of the lower surface of the lip of the embedded duct, so that the leading edge upper surface of the ducted section wing and the lower surface of the lip of the embedded duct form a continuous curvature transition. For the specific local fusion and modification method, please refer to the detailed description of the following step S1.

[0026] The shape of the duct wall of the embedded duct is continuously integrated with the local curved surface of the duct section wing, and forms a continuous aerodynamic shape through the transition section between the upper and lower wings to form an integrated duct intake structure.

[0027] The outer wing sections are arranged on both sides of the ducted wing section. They are formed by extending the initial airfoil along the spanwise direction. Their airfoil shape remains unchanged. They are used to maintain the overall lift distribution characteristics and aerodynamic efficiency of the wing and together with the ducted wing section, they form a complete wing aerodynamic layout.

[0028] The embedded duct adopts an axisymmetric flow channel structure similar to that of a conventional ducted fan. The embedded ducts are arranged in an array along the spanwise direction of the duct section of the wing, with adjacent embedded ducts closely spaced without gaps. This allows multiple embedded ducts to form a continuous distributed propulsion configuration in the leading edge region of the duct section of the wing, thereby reducing the additional drag caused by the gaps between the ducts and improving the space utilization and propulsion system integration in the leading edge region of the duct section of the wing.

[0029] In this invention, the inlet region of the embedded duct is embedded inside the leading edge of the duct section wing, and its inlet lip shape is continuously integrated with the local curved surface of the duct section wing to form an integrated duct intake structure. The duct section wing, the outer wing section, and the embedded duct together form a duct-embedded aerodynamic integration configuration, enabling the duct propulsion system and the wing aerodynamic shape to be integrated into a single design, thereby balancing propulsion efficiency and wing aerodynamic performance.

[0030] Please see Figure 1 The present invention also provides an integrated design optimization method for a leading-edge embedded distributed ducted fan powered wing, the method comprising the following steps:

[0031] Step S1: Establish a parameterized model of the aerodynamic blended configuration including the ducted wing section, the outer wing section, and each embedded duct. The parameterized model includes a parameterized model of the wing composed of the ducted wing section and the outer wing section, and a parameterized model of the ducted propulsion system composed of each embedded duct.

[0032] The aerodynamic blending configuration, which includes the ducted wing section, the outer wing section, and each embedded duct, is an aerodynamic blending configuration obtained by partially blending and modifying the upper leading edge of the ducted wing section according to the shape of the lower surface of the lip of the embedded duct. The method of partial blending and modification is expressed as follows:

[0033] (1)

[0034] in: This indicates the leading edge surface of the wing with integrated modification of the front duct section; This indicates the leading edge surface of the wing with integrated and modified duct section; Indicates the normal direction of the wing leading edge; This represents the modification factor, used to control the modification range;

[0035] The deformation displacement, calculated based on the distance from the duct lip to the duct section of the wing before the integrated deformation, is expanded as follows:

[0036] (2)

[0037] This indicates the curved surface of the lower surface of the embedded duct lip;

[0038] The local modification weight function, distributed along the wing chord, can be expanded as follows:

[0039] (3) Among them: The dimensionless distance coordinate along the chord direction of the wing is defined as:

[0040] (4)

[0041] in: This indicates the actual coordinates of the wing's chordal position; This indicates the center of the fusion area between the duct lip and the wing; Indicates the chord length of a portion of the wing; This indicates the control parameter for the influence range of the shaping, used to adjust the range of influence of the fusion region along the chord direction; The range of values ​​is This is used to define the shaping area, so that the shaping amount continuously decreases from the fusion area to the surrounding area; when At that time, it corresponds to the integration of the regional center; when At this time, corresponding to the non-fusion region, the ducted section wing shape remains unchanged;

[0042] Furthermore, the ducted section of the wing's leading edge surface, after integration and modification, and the lower surface of the embedded duct lip meet at the connection boundary. Geometric continuity is satisfied at the location ,in, This indicates the leading edge surface of the ducted section of the wing at the junction boundary. The curved surface at that point; This indicates the curved surface of the lower surface of the embedded duct lip at the connection boundary. The surface at that point satisfies the curvature continuity relation: ; and These represent the curvatures of the leading edge of the ducted section of the wing after the fusion modification and the lower surface of the embedded duct lip at the connection boundary, respectively.

[0043] By using the aforementioned partial fusion modification method, the shape of the embedded duct lip is used as a geometric constraint to partially reconstruct the leading edge of the duct section of the wing. This allows the upper surface of the leading edge of the duct section of the wing to form a continuous and smooth transition surface with the lower surface of the embedded duct lip. This reduces airflow separation and local drag in the connection area between the duct and the wing, improves the airflow quality in the duct inlet area, and achieves an integrated design of the duct propulsion system and the wing aerodynamic shape.

[0044] Step S2: Based on the influence range and intensity of the embedded ducted jet on the wing surface flow field, the cross-sections at different positions along the wing span are classified, and a differentiated cross-section deformation strategy is established:

[0045] For each section located on the outer wing segment, the airfoil shape at the section is kept unchanged to maintain the overall lift distribution characteristics of the wing. For the section located at the center of each embedded duct, a joint parametric deformation strategy is established, and the airfoil geometry parameters of the duct section and the inner wall geometry parameters of the embedded duct are parametrically controlled to achieve coordinated deformation. For the section located at the duct junction where the embedded duct meets the wing, a separate parametric deformation strategy is established, and the airfoil geometry parameters of the duct section are parametrically controlled only at the section.

[0046] For the cross-section at the center of the duct, including the duct section airfoil cross-section and the embedded duct inner wall cross-section, a first FFD control frame covering the duct section airfoil cross-section and a second FFD control frame covering the embedded duct inner wall cross-section are constructed respectively. By coordinating the control point positions of the first FFD control frame and the second FFD control frame, the coordinated deformation of the geometry of the duct section airfoil and the embedded duct inner wall is achieved.

[0047] For the section at the junction of the duct, a third FFD control frame is constructed to cover the airfoil section of the duct segment at the section. By controlling the position of each control point in the third FFD control frame, the geometry of the airfoil section of the duct segment is deformed.

[0048] As one implementation method, a differentiated cross-sectional deformation strategy is constructed using the free deformation (FFD) method, specifically including:

[0049] The expression for FFD is:

[0050]

[0051] in: This indicates the position coordinates of the FFD control points before the transformation. These represent the three directions in the FFD control point space; This indicates the position coordinates of the FFD control points after the transformation; These represent the dimensionless local coordinate parameters in three directions within the FFD control space; These represent the order of the FFD control box in the three directions, respectively; These are Bernstein basis functions.

[0052] In this step, based on the influence range of the embedded ducted jet on the wing flow field, different spanwise sections are divided into regions, and a differentiated section deformation strategy is established, expressed by the following formula:

[0053] Let the set of sections along the wing span be... ; Indicates the first A cross section, Indicates the number of cross sections.

[0054] Establish a classification function based on cross-section type. :

[0055]

[0056] Based on the cross-section classification results, different FFD parameterization strategies are applied to different cross-sections:

[0057] Let each FFD control frame have a set of FFD control points. ; Indicate the coordinates of each control point; This indicates the number of FFD control points in a single FFD control box;

[0058] The control point update method during optimization is as follows: ;in, ; This indicates that the FFD control points of the ducted section wing have been adjusted. This indicates the adjustment of the FFD control points on the inner wall of the embedded duct. This indicates the control step size. This indicates the overall adjustment amount of the FFD control points; Indicates the first The set of FFD control points of the FFD control box at the next iteration; Indicates the first The set of FFD control points of the FFD control box at the next iteration;

[0059] Its transformation operator is expressed as:

[0060]

[0061] in: This represents the combined deformation strategy of the cross-section at the center of the duct, while simultaneously adjusting the airfoil of the duct section and the geometric parameters of the embedded duct inner wall surface; This represents a separate deformation strategy for the section at the duct junction, adjusting only the airfoil geometry parameters of the duct section. By employing different FFD deformation operators, differentiated parametric design of aerodynamic shapes in different spanwise regions can be achieved. and These represent the set of FFD control points for the duct section airfoil section and the set of FFD control points for the embedded duct inner wall section, respectively.

[0062] Furthermore, for areas directly affected by the ducted jet, the airfoil shape is adjusted by localized strengthening deformation; for areas less affected by the jet or not affected by the jet, conventional deformation is used for adjustment, thereby achieving differentiated aerodynamic shape design for different areas.

[0063] The local strengthening deformation strategy based on the intensity of the duct jet influence is expressed as:

[0064] (19)

[0065] (20)

[0066] in: Representing the cross section The FFD deformation of the airfoil or embedded duct inner wall of the duct section; Indicates the deformation amount of a standard FFD; The local intensification coefficient is defined as the area directly affected by the duct jet, specifically the cross-section at the center of the duct. Areas less affected by duct jets ; Indicates the intensity of the jet's influence; Representing the cross section The average axial velocity at that location; This indicates the velocity of the free flow.

[0067] Step S3: Establish a performance synergistic optimization model for the aerodynamic blend configuration. Select parameters characterizing the aerodynamic shape of the wing and the layout of the propulsion system as design variables. Specifically, use the ducted section wing airfoil geometry parameters, the embedded duct inner wall geometry parameters, and the embedded duct fan position parameters as design variables. Take the optimal comprehensive performance of the aerodynamic blend configuration calculated based on the comprehensive evaluation function as the optimization objective, and use the lift coefficient and pitching moment coefficient as optimization constraints. Based on the differentiated cross-section deformation strategy, carry out integrated iterative design optimization of the ducted propulsion system and the wing aerodynamic shape to obtain the optimized aerodynamic blend configuration.

[0068] As one implementation method, design variables are represented as ; This indicates the geometric parameters of the ducted section airfoil. Indicates the geometric parameters of the inner wall of the embedded duct. This represents the position parameters of the embedded ducted fan. The design variables are applied to the FFD control points, and the geometric update of the corresponding area is achieved by changing the position of the FFD control points.

[0069] This step is specifically implemented through steps S31 to S33:

[0070] Step S31: At the beginning of each optimization round, obtain the adjustment amount of each design variable determined in the previous optimization round at each cross section;

[0071] Step S32: Based on the FFD control frame at each section, the design variable adjustment amount is mapped to the control point position change amount of the corresponding FFD control frame, so as to achieve the coordinated deformation of the geometry of the duct section airfoil and the embedded duct inner wall at the duct center section, as well as the deformation of the geometry of the duct section airfoil at the duct junction section, to obtain the updated aerodynamic blending configuration.

[0072] Step S33: Conduct a comprehensive aerodynamic performance analysis on the updated aerodynamic fusion configuration. Evaluate the comprehensive aerodynamic performance of the aerodynamic fusion configuration based on the comprehensive evaluation function. If the change in the comprehensive aerodynamic performance of this optimization round relative to the comprehensive aerodynamic performance of the previous optimization round is less than a set threshold, stop the iterative optimization and output the updated aerodynamic fusion configuration; otherwise, based on the change in comprehensive aerodynamic performance and by introducing a local strengthening deformation strategy based on the influence intensity of the duct jet, set the adjustment amount of each design variable at each cross section, and return to step S31 for iterative optimization.

[0073] In this step, the comprehensive evaluation function is expressed as:

[0074] (5)

[0075] in: This represents the comprehensive evaluation function; This represents the function for evaluating the aerodynamic performance of the ducted section of the wing. A wing aerodynamic performance evaluation function representing coupled propulsion performance; This represents the propulsion performance evaluation function of the propulsion system; This represents the function for evaluating the flow field quality at the duct inlet; This represents the geometric smoothing penalty term; These are the weight coefficients for each evaluation item, and they satisfy the following: .

[0076] The evaluation items are represented as follows:

[0077] Evaluation function of ducted section wing aerodynamic performance :

[0078] (6)

[0079] in: This indicates the lift-to-drag ratio of the ducted section of the wing. This indicates the lift coefficient of the ducted section of the wing. This indicates the drag coefficient of the ducted section of the wing; This indicates the pitch moment penalty coefficient for the ducted section of the wing; This indicates the pitching moment coefficient of the ducted section of the wing;

[0080] Aerodynamic performance evaluation function for airfoil with coupled propulsion performance :

[0081] (7)

[0082] in: Indicates the lift-to-drag ratio of the wing; Indicates the wing lift coefficient; Indicates the wing drag coefficient; This represents the weighting coefficient. This indicates the lift generated by the ducted jet stream; This indicates the wing pitch moment penalty coefficient; Indicates the wing pitching moment coefficient;

[0083] Propulsion system propulsion performance evaluation function :

[0084] Specifically, in order to evaluate the contribution of the propulsion system to the aerodynamic performance of the wing, a propulsion performance evaluation function of the propulsion system is established.

[0085] ① Ducted jet flow coefficient Represented as:

[0086] (8)

[0087] Where: ducted jet flow coefficient This is used to characterize the degree of influence of the embedded ducted jet on the airfoil flow field relative to the free flow rate. Indicates the number of embedded ducts; Indicates the first Jet mass flow rate at the outlet of an embedded duct; Indicates the first Average axial velocity of the outlet section of the embedded duct; Indicates the free flow density; Indicates the velocity of the free flow; Indicates the wing reference area;

[0088] ② Propulsion system efficiency Represented as:

[0089] (9)

[0090] in: Indicates the input power of the propulsion system; express The total thrust generated by the embedded duct , Indicates the first The thrust generated by the embedded duct; With total thrust coefficient The relation is:

[0091] (10)

[0092] ③ Change in wing drag Represented as:

[0093] (11)

[0094] in: This indicates the wing drag coefficient when the ducted jet is activated; This represents the wing drag coefficient under ductless jet flow conditions.

[0095] ④ Establish aerodynamic and propulsion coupling benefit index :

[0096] (12)

[0097] in: Weighting coefficients representing changes in wing drag; Weighting coefficients representing the change in wing pitching moment; This indicates the change in wing pitching moment;

[0098] ⑤ Propulsion system propulsion performance evaluation function Represented as:

[0099] (13) Among them: This represents the coupling benefit weighting coefficient;

[0100] Duct inlet flow field quality evaluation function :

[0101] Specifically, in order to evaluate the flow field quality at the duct inlet, an evaluation function for the flow field quality at the duct inlet is established.

[0102] ① Average normal velocity at duct inlet Represented as:

[0103] (14)

[0104] in: This represents the cross-sectional area of ​​the culvert inlet; ① Local normal velocity at the culvert inlet section; ② Culvert inlet velocity distortion index Represented as: (15) ③ Total pressure recovery coefficient at culvert inlet Represented as:

[0105] (16)

[0106] in: This represents the average total pressure at the culvert inlet section; Indicates the total pressure of the free flow;

[0107] ④ Evaluation function of flow field quality at duct inlet Represented as:

[0108] (17)

[0109] in: and These represent the weighting coefficients corresponding to the duct inlet velocity distortion and the duct inlet total pressure recovery coefficient, respectively.

[0110] Geometric smoothness penalty Represented as:

[0111] (18) Among them: This indicates the wing surface after integration and modification. Indicates the area to be fused and modified; This represents the Laplace operator, used to describe the second-order spatial variation characteristics of a surface;

[0112] Geometric smoothing penalty This ensures that the wing, after integration and modification, has a continuous and smooth geometric shape.

[0113] The design variables are iteratively adjusted according to the optimization objective. The next optimization is: ;until This resulted in an optimized configuration of the distributed leading-edge embedded ducted fan airfoil that met design requirements. , respectively representing the first The values ​​of the design variables during the second optimization, the first The values ​​of the design variables during the second optimization, and the values ​​of the third optimization variables. Changes in design variables during the second optimization; and , respectively representing the first The second optimization and the first The value of the comprehensive evaluation function during the second optimization; This is a preset threshold.

[0114] Therefore, the present invention has the following design features:

[0115] In this invention, different parametric deformation methods and deformation amplitudes are adopted for different spanwise cross sections, including the cross section at the center of the duct and the cross section at the duct junction. The airfoil deformation in the region affected by the duct jet focuses on adjusting the duct embedding area, the duct jet outlet area, and the thickness distribution to improve the matching relationship between the duct jet and the airfoil surface flow field.

[0116] In the comprehensive evaluation function of this invention, Used to evaluate the aerodynamic efficiency of local airfoils. This invention is used to evaluate the synergistic lift enhancement effect between the ducted jet and the wing, thereby achieving unified optimization of local aerodynamic characteristics and overall aerodynamic performance. By establishing a collaborative optimization design framework for airfoils and wings, this invention integrates airfoil optimization with the wing aerodynamic / propulsion coupling optimization process, realizing the collaborative optimization design of a distributed leading-edge embedded ducted fan wing.

[0117] The present invention will now be described in further detail with reference to the accompanying drawings.

[0118] This embodiment describes an overall configuration of a leading-edge embedded distributed ducted fan powered wing, such as... Figure 2 As shown, the wing consists of a ducted section wing 1, an outer wing section, and embedded ducts 4. The ducted section wing 1 is located in the central region of the wing, and multiple embedded ducts 4 are closely arranged along the span of the wing and embedded inside the leading edge of the ducted section wing 1. The outer wing sections are located on both sides of the ducted section wing 1, formed by extending the initial airfoil along the span, and together with the ducted section wing 1, they constitute a complete wing aerodynamic layout. The wing span is designed to be 6 m, and the ducted section wing 1 has a designed span of 2 m.

[0119] This embodiment illustrates the ducted section wing layout structure used in this invention, such as... Figure 3 As shown, multiple embedded ducts 4 are arranged in an array along the spanwise direction of the ducted wing section 1, with adjacent ducts closely spaced. The diameter of the ducts is designed to be 0.3m. The leading edge of the ducted wing section 1 is shaped to blend with the shape of the embedded ducts 4, so that the upper surface of the leading edge of the ducted wing section 1 and the lower surface of the lip of the embedded duct 4 form a continuous transition surface, thereby forming an integrated aerodynamic propulsion configuration.

[0120] This embodiment illustrates the airfoil cross-section structure at the center of the duct used in this invention, such as... Figure 4 As shown, the embedded duct 4 is located in the leading edge region of the airfoil. The inner wall section 5 of the embedded duct and the airfoil section 6 of the duct section together form the aerodynamic shape at the center of the duct. The leading edge of the airfoil section 6 of the duct section is locally modified according to the shape of the duct, so that a continuous curvature transition relationship is formed between the leading edge of the airfoil and the outer wall of the duct. This design can improve the flow field quality in the duct inlet region, reduce local flow separation, and enhance the aerodynamic coupling between the duct jet and the airfoil flow field.

[0121] This embodiment illustrates the leading-edge embedded distributed ducted fan powered wing cooperative optimization method employed in this invention, such as... Figure 5 and Figure 6 As shown, a parametric model of the ducted section of the airfoil is first established, and the airfoil parametric control frame is constructed using the free deformation (FFD) method. Based on the degree of influence of the ducted jet on the airfoil flow field, differentiated deformation strategies are established for sections at different spanwise positions.

[0122] like Figure 5 As shown, an FFD control frame is established at the center section of the duct. Since this region includes the embedded duct 4 and its surrounding wing aerodynamic shape, it is the main area where the duct jet and wing flow field directly couple. Therefore, two FFD control frames are used to cover the embedded duct inner wall section 5 and the duct section wing airfoil section 6, respectively. By adjusting the positions of the FFD control points, the airfoil camber and thickness distribution of the duct section wing 1, as well as the inner wall shape of the embedded duct 4, are parametrically controlled. This achieves coordinated deformation of the aerodynamic shape in the duct-wing fusion region, thereby improving the matching relationship between the duct jet and the wing surface flow field and enhancing aerodynamic / propulsion coupling performance.

[0123] like Figure 6 As shown, an FFD control frame for the duct junction section is established at the duct junction section. This region adopts a different parametric deformation strategy than the section at the duct center. Only one FFD control frame is established covering the duct section airfoil section 6. By adjusting the local camber, thickness distribution, and leading edge shape of the airfoil, a smooth transition between the duct-affected area and the non-duct-affected area is achieved, thereby improving the overall aerodynamic performance of the wing and ensuring the continuity of the spanwise aerodynamic load distribution.

[0124] This embodiment illustrates the collaborative optimization process for a leading-edge embedded distributed ducted fan powered wing used in this invention, such as... Figure 1 As shown, a distributed leading-edge embedded ducted wing parametric model is first established, and a parametric control frame is constructed using the free deformation (FFD) method. Specifically, the cross-section at the duct center parametrically controls both the ducted section airfoil and the inner wall of the embedded duct, while the cross-section at the duct junction only parametrically controls the ducted section airfoil. Based on whether the cross-section includes the embedded duct and the degree of influence of the duct jet, the wing spanwise cross-sections are classified, and differentiated parametric deformation strategies are established.

[0125] For the section at the center of the duct, a combined deformation approach of the wing and duct is adopted. This involves adjusting the position of the FFD control points to achieve coordinated deformation of the wing airfoil within the duct section and the embedded inner wall of the duct. For the section at the duct junction, a separate wing deformation approach is used, parametrically adjusting the geometric characteristics of the wing airfoil within the duct section. Through these differentiated deformation strategies, targeted optimization design is achieved for both the jet flow impact area and the non-jet flow impact area.

[0126] After completing parametric modeling, aerodynamic performance analysis was conducted on different configurations using the ducted airfoil geometry, embedded duct inner wall geometry, and embedded ducted fan position parameters as design variables. Simultaneously, airfoil aerodynamic performance and wing aerodynamic / propulsion coupling performance were evaluated, with lift coefficient and pitching moment coefficient used as constraints for iterative optimization. Ultimately, an optimized configuration for a leading-edge embedded distributed ducted fan powered wing was obtained, balancing local airfoil aerodynamic characteristics with overall aerodynamic / propulsion coupling performance.

[0127] The proposed leading-edge embedded distributed ducted fan powered wing integrates multiple ducts closely along the wing's leading edge spanwise, achieving deep integration of the propulsion system with the wing's aerodynamic shape. Compared to traditional externally mounted distributed propulsion layouts, this invention embeds the propulsion system within the wing, reducing additional interference from the propulsion device on the external flow field and the extra drag from structural installation, while improving the space utilization and propulsion system integration in the wing's leading edge region. Compared to trailing-edge distributed propulsion layouts, this invention places the propulsion device in the wing's leading edge region, enabling active control of the flow field before the airflow enters the wing body. This allows the ducted jet to couple with the wing's flow field over a longer distance, generating a significant "Conrad effect," thus more fully leveraging the jet lift enhancement and aerodynamic propulsion synergy.

[0128] This invention, through the continuous integration design of the duct lip and the wing surface, forms a smooth intake channel that matches the duct inlet. This improves the uniformity of the flow field at the duct inlet, reduces inlet air distortion and local flow separation, and enhances the operational stability of the propulsion system. Simultaneously, the continuous curved surface configuration formed between the ducted wing section and the embedded duct effectively mitigates boundary layer losses caused by geometrical abrupt changes, achieving organic unity between the wing's aerodynamic shape and the propulsion system's shape, and providing a new configuration scheme for integrated aerodynamic and propulsion design.

[0129] This invention establishes a collaborative optimization design method applicable to aerodynamic / propulsion coupled airfoils, unifying and integrating airfoil optimization with airfoil optimization processes. During optimization, both airfoil aerodynamic characteristics and aerodynamic coupling characteristics under the influence of ducted jets are considered simultaneously, overcoming the limitations of traditional optimization methods that only perform single-level optimization for airfoils or the entire airfoil. Addressing the significant differences in flow mechanisms and aerodynamic characteristics across different spanwise regions of the airfoil under ducted jet influence, this invention proposes a parametric optimization method based on a differentiated cross-section deformation strategy. Different deformation methods and optimization strategies are applied to different cross-sections according to the degree of jet influence, enabling the jet-affected and non-jet-affected regions to evolve towards their respective optimal aerodynamic forms, achieving collaborative optimization of local flow field characteristics and overall aerodynamic / propulsion coupling performance.

[0130] Through the above-mentioned configuration design and optimization methods, this invention can fully exploit the beneficial coupling effect between the ducted jet and the wing flow field, and improve the overall aerodynamic efficiency of the wing and the comprehensive performance of the propulsion system while taking into account lift characteristics, drag characteristics and pitch moment characteristics. This provides a new technical approach for the design of distributed electric propulsion aircraft and aerodynamic propulsion integrated aircraft.

[0131] The most significant feature of the distributed ducted fan wing of this invention is its leading-edge embedded layout. The most significant feature of the optimization method for the leading-edge embedded distributed ducted fan powered wing of this invention is the integration of airfoil and wing optimization modules, employing a parameterized method with a differentiated cross-section deformation strategy. Currently, no similar leading-edge embedded distributed ducted fan powered wing design scheme or optimization method has been publicly disclosed; this invention fills that gap.

[0132] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A leading-edge embedded distributed ducted fan powered wing, characterized in that, The system includes a wing and an embedded duct; the wing includes a ducted wing section and outer wing sections arranged along the spanwise direction of the ducted wing section on both the inner and outer sides of the ducted wing section; the embedded ducts are arranged in an array along the spanwise direction of the ducted wing section in the leading edge region of the ducted wing section, and adjacent embedded ducts are closely spaced without gaps, with the entrance region of each embedded duct embedded inside the leading edge of the ducted wing section, forming a continuous distributed ducted propulsion system.

2. The leading-edge embedded distributed ducted fan powered wing according to claim 1, characterized in that, The lower surface of the lip of the embedded duct is continuously fused with the upper surface of the leading edge of the duct section wing.

3. The leading-edge embedded distributed ducted fan powered wing according to claim 1, characterized in that, The upper leading edge surface of the ducted section wing is partially fused and modified according to the shape of the lower lip surface of the embedded duct, so that the upper leading edge surface of the ducted section wing and the lower lip surface of the embedded duct form a continuous curvature transition.

4. The leading-edge embedded distributed ducted fan powered wing according to claim 1, characterized in that, The shape of the duct wall of the embedded duct is continuously integrated with the local curved surface of the duct section wing, and forms a continuous aerodynamic shape through the transition section between the upper and lower wings to form an integrated duct intake structure.

5. An integrated design optimization method for a leading-edge embedded distributed ducted fan powered airfoil, characterized in that, The method for integrated design optimization of a leading-edge embedded distributed ducted fan powered wing according to any one of claims 1 to 4 includes the following steps: Step S1: Establish a parameterized model of the aerodynamic blended configuration including the ducted wing section, the outer wing section, and each embedded duct. The parameterized model includes a parameterized model of the wing composed of the ducted wing section and the outer wing section, and a parameterized model of the ducted propulsion system composed of each embedded duct. Step S2: Based on the influence range and intensity of the embedded ducted jet on the wing surface flow field, the cross-sections at different positions along the wing span are classified, and a differentiated cross-section deformation strategy is established: For each section located on the outer wing segment, the airfoil shape at the section is kept unchanged to maintain the overall lift distribution characteristics of the wing. For the section located at the center of each embedded duct, a joint parametric deformation strategy is established, and the airfoil geometry parameters of the duct section and the inner wall geometry parameters of the embedded duct are parametrically controlled to achieve coordinated deformation. For the section located at the duct junction where the embedded duct meets the wing, a separate parametric deformation strategy is established, and the airfoil geometry parameters of the duct section are parametrically controlled only at the section. Step S3: Establish a performance synergistic optimization model for the aerodynamic blending configuration. Use the ducted section wing airfoil geometry parameters, embedded duct inner wall geometry parameters, and embedded duct fan position parameters as design variables. Use the optimal comprehensive performance of the aerodynamic blending configuration calculated based on the comprehensive evaluation function as the optimization objective. Use the lift coefficient and pitching moment coefficient as optimization constraints. Based on the differentiated cross-section deformation strategy, carry out integrated iterative design optimization of the ducted propulsion system and the wing aerodynamic shape to obtain the optimized aerodynamic blending configuration.

6. The integrated design optimization method for a leading-edge embedded distributed ducted fan powered wing according to claim 5, characterized in that, The aerodynamic blending configuration, which includes the ducted wing section, the outer wing section, and each embedded duct, is an aerodynamic blending configuration obtained by partially blending and modifying the upper leading edge of the ducted wing section according to the shape of the lower surface of the embedded duct lip. The method of partial blending and modification is expressed as follows: （1） in: This indicates the leading edge surface of the wing with integrated modification of the front duct section; This indicates the leading edge surface of the wing with integrated and modified duct section; Indicates the normal direction of the wing leading edge; This represents the modification factor, used to control the modification range; The deformation displacement, calculated based on the distance from the duct lip to the duct section of the wing before the integrated deformation, is expanded as follows: （2） This indicates the curved surface of the lower surface of the embedded duct lip; The local modification weight function, distributed along the wing chord, can be expanded as follows: (3) Among them: The dimensionless distance coordinate along the chord direction of the wing is defined as: （4） in: This indicates the actual coordinates of the wing's chordal position; This indicates the center of the fusion area between the duct lip and the wing; Indicates the chord length of a portion of the wing; This indicates the control parameter for the influence range of the shaping, used to adjust the range of influence of the fusion region along the chord direction; The range of values ​​is This is used to define the shaping area, so that the shaping amount continuously decreases from the fusion area to the surrounding area; when At that time, it corresponds to the integration of the regional center; when At this time, corresponding to the non-fusion region, the ducted section wing shape remains unchanged; By using a local fusion and reshaping method, the shape of the embedded duct lip is used as a geometric constraint to locally reconstruct the leading edge of the duct section of the wing, so that the upper surface of the leading edge of the duct section of the wing and the lower surface of the embedded duct lip form a continuous and smooth transition surface.

7. The integrated design optimization method for a leading-edge embedded distributed ducted fan powered wing according to claim 5, characterized in that, Differentiated cross-sectional deformation strategies are constructed using the free deformation (FFD) method, specifically including: For the cross-section at the center of the duct, including the duct section airfoil cross-section and the embedded duct inner wall cross-section, a first FFD control frame covering the duct section airfoil cross-section and a second FFD control frame covering the embedded duct inner wall cross-section are constructed respectively. By coordinating the control point positions of the first FFD control frame and the second FFD control frame, the coordinated deformation of the geometry of the duct section airfoil and the embedded duct inner wall is achieved. For the section at the junction of the duct, a third FFD control frame is constructed to cover the airfoil section of the duct segment at the section. By controlling the position of each control point in the third FFD control frame, the geometry of the airfoil section of the duct segment is deformed.

8. The integrated design optimization method for a leading-edge embedded distributed ducted fan powered wing according to claim 7, characterized in that, Based on the aforementioned differentiated cross-section deformation strategy, an integrated iterative design optimization of the ducted propulsion system and the wing aerodynamic shape is carried out, specifically including: Step S31: At the beginning of each optimization round, obtain the adjustment amount of each design variable determined in the previous optimization round at each cross section; Step S32: Based on the FFD control frame at each section, the design variable adjustment amount is mapped to the control point position change amount of the corresponding FFD control frame, so as to achieve the coordinated deformation of the geometry of the duct section airfoil and the embedded duct inner wall at the duct center section, as well as the deformation of the geometry of the duct section airfoil at the duct junction section, to obtain the updated aerodynamic blending configuration. Step S33: Conduct a comprehensive aerodynamic performance analysis on the updated aerodynamic fusion configuration. Evaluate the comprehensive aerodynamic performance of the aerodynamic fusion configuration based on the comprehensive evaluation function. If the change in the comprehensive aerodynamic performance of this optimization round relative to the comprehensive aerodynamic performance of the previous optimization round is less than a set threshold, stop the iterative optimization and output the updated aerodynamic fusion configuration; otherwise, based on the change in comprehensive aerodynamic performance and by introducing a local strengthening deformation strategy based on the influence intensity of the duct jet, set the adjustment amount of each design variable at each cross section, and return to step S31 for iterative optimization.

9. The integrated design optimization method for a leading-edge embedded distributed ducted fan powered wing according to claim 8, characterized in that, The comprehensive evaluation function is expressed as follows: （5） in: This represents the comprehensive evaluation function; This represents the function for evaluating the aerodynamic performance of the ducted section of the wing. A wing aerodynamic performance evaluation function representing coupled propulsion performance; This represents the propulsion performance evaluation function of the propulsion system; This represents the function for evaluating the flow field quality at the duct inlet; This represents the geometric smoothing penalty term; These are the weight coefficients for each evaluation item, and they satisfy the following: .

10. The integrated design optimization method for a leading-edge embedded distributed ducted fan powered wing according to claim 9, characterized in that, The evaluation items are represented as follows: Evaluation function of ducted section wing aerodynamic performance : （6） in: This indicates the lift-to-drag ratio of the ducted section of the wing. This indicates the lift coefficient of the ducted section of the wing. This indicates the drag coefficient of the ducted section of the wing; This indicates the pitch moment penalty coefficient for the ducted section of the wing; This indicates the pitching moment coefficient of the ducted section of the wing; Aerodynamic performance evaluation function for airfoil with coupled propulsion performance : （7） in: Indicates the lift-to-drag ratio of the wing; Indicates the wing lift coefficient; Indicates the wing drag coefficient; This represents the weighting coefficient. This indicates the lift generated by the ducted jet stream; This indicates the wing pitch moment penalty coefficient; Indicates the wing pitching moment coefficient; Propulsion system propulsion performance evaluation function : ① Ducted jet flow coefficient Represented as: （8） Where: ducted jet flow coefficient This is used to characterize the degree of influence of the embedded ducted jet on the airfoil flow field relative to the free flow rate. Indicates the number of embedded ducts; Indicates the first Jet mass flow rate at the outlet of an embedded duct; Indicates the first Average axial velocity of the outlet section of the embedded duct; Indicates the free flow density; Indicates the velocity of the free flow; Indicates the wing reference area; ② Propulsion system efficiency Represented as: （9） in: Indicates the input power of the propulsion system; express The total thrust generated by the embedded duct , Indicates the first The thrust generated by the embedded duct; With total thrust coefficient The relation is: （10） ③ Change in wing drag Represented as: （11） in: This indicates the wing drag coefficient when the ducted jet is activated; This represents the wing drag coefficient under ductless jet flow conditions. ④ Establish aerodynamic and propulsion coupling benefit index : （12） in: Weighting coefficients representing changes in wing drag; Weighting coefficients representing the change in wing pitching moment; This indicates the change in wing pitching moment; ⑤ Propulsion system propulsion performance evaluation function Represented as: (13) Among them: This represents the coupling benefit weighting coefficient; Duct inlet flow field quality evaluation function : ① Average normal velocity at duct inlet Represented as: （14） in: This represents the cross-sectional area of ​​the culvert inlet; ① Local normal velocity at the culvert inlet section; ② Culvert inlet velocity distortion index Represented as: (15) ③ Total pressure recovery coefficient at culvert inlet Represented as: （16） in: This represents the average total pressure at the culvert inlet section; Indicates the total pressure of the free flow; ④ Evaluation function of flow field quality at duct inlet Represented as: （17） in: and These represent the weighting coefficients corresponding to the duct inlet velocity distortion and the duct inlet total pressure recovery coefficient, respectively. Geometric smoothness penalty Represented as: (18) Among them: This indicates the wing surface after integration and modification. Indicates the area to be fused and modified; This represents the Laplace operator, used to describe the second-order spatial variation characteristics of a surface; The local strengthening deformation strategy based on the intensity of the duct jet influence is expressed as: （19） （20） in: Representing the cross section The FFD deformation of the airfoil or embedded duct inner wall of the duct section; Indicates the deformation amount of a standard FFD; The local intensification coefficient is defined as the area directly affected by the duct jet, specifically the cross-section at the center of the duct. Areas less affected by duct jets ; Indicates the intensity of the jet's influence; Representing the cross section The average axial velocity at that location; This indicates the velocity of the free flow.

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