Aerodynamic Evaluation Method, System, Equipment and Medium for a Compound Dual-Rotor Power Plant

Abstract

The present invention provides a pneumatic evaluation method, system, device and medium for a compound dual-rotor power device, which is characterized by including: obtaining rotor data and wind field data of the dual-rotor power device; calculating the aerodynamic performance of the upstream lift rotor and the upstream equilibrium induced wind speed according to the obtained data; taking the upstream equilibrium induced wind speed as the inflow wind speed of the drag rotor area, and calculating the equilibrium induced wind speed in the drag rotor influence area and the aerodynamic performance of the drag rotor area; taking the upstream equilibrium induced wind speed outside the influence area and the equilibrium induced wind speed in the drag rotor influence area as the inflow wind speed of the downstream lift rotor, and calculating the aerodynamic performance of the downstream lift rotor; thereby obtaining the aerodynamic performance of the dual-rotor power device.

Description

Technical Field

[0001] This document relates to the field of aerodynamic evaluation of dual-rotor power devices, and particularly to a composite dual-rotor power device aerodynamic evaluation method, system, device, and medium. Background Art

[0002] Wind energy, as a major renewable clean energy source, is an important development direction in the new energy field. The rotor device is the main form of wind energy utilization, including two basic forms: the horizontal-axis rotor device and the vertical-axis rotor device. The vertical-axis rotor device includes two structural forms: the lift-type (Darrieus-type) rotor device and the drag-type (Savonius-type) rotor device. The Savonius-type rotor device has a simple structure and is easy to start, but has low efficiency. The Darrieus-type rotor device has a large tip speed ratio and high wind energy utilization rate, but has poor starting performance. To improve the starting performance of the Darrieus-type rotor device, researchers combined the Savonius-type rotor with the Darrieus-type rotor and proposed a composite dual-rotor power device with a drag cup structure, greatly expanding the application range of the vertical-axis rotor device.

[0003] In the design and application of rotor devices, the analysis and evaluation of the aerodynamic performance of rotor devices is a very important link. The rotor flow field of the Darrieus-type rotor device is more complex than that of the horizontal-axis rotor device. For the aerodynamic performance analysis of the Darrieus-type rotor device, the commonly used calculation models in the engineering design field are the single-streamtube model, the multi-streamtube model, and the double-actuator disk multi-streamtube model. Among them, due to the strict limitations of the assumptions of the single-streamtube model, it cannot provide relatively accurate calculation results in many application scenarios. The multi-streamtube model proposed by Strickland is based on the Glauert blade element theory, assuming that a series of identical streamtubes pass through the rotor, and each streamtube uses the basic principle of the single-streamtube model, and the momentum equation calculates that the flow force in the flow direction is equal to the flow force acting on the blade airfoil. Compared with the single-streamtube model, the induced velocity of different streamtubes is different due to the phase angle θ where the streamtube is located, and the calculation accuracy has been greatly improved. The double-actuator disk - multi-streamtube aerodynamic model was proposed by Paraschivoiu by combining the double-actuator disk theory proposed by Lapin et al., which can calculate the aerodynamic loads of straight and curved blade Darrieus wind turbines, has high accuracy, and is widely used in engineering. For the Savonius-type rotor device, the calculation of the rotor aerodynamic performance mostly refers to the horizontal horizontal rotor device to obtain the wind energy utilization coefficient according to experience, and then multiplies it by the wind energy input in the blade swept area. The pertinence, accuracy, and reliability of its value largely depend on the empirical value. Chen Zhongwei gave the calculation formulas for the force and average power of the drag rotor blade by analyzing the force situation of the blade and referring to the external fluid resistance calculation method. For the composite dual-rotor power device, there is currently no mature integrated aerodynamic analysis method. Summary of the Invention

[0004] The present invention aims to solve the above problems by providing a pneumatic evaluation method, system, device and medium for a compound dual-rotor power device.

[0005] An embodiment of the present invention provides a pneumatic evaluation method for a compound dual-rotor power device, including:

[0006] S1. Obtain the rotor data and wind field data of the dual-rotor power device;

[0007] S2. Calculate the aerodynamic performance of the upwind region lift rotor and the upwind region equilibrium induced wind speed according to the data obtained in step S1;

[0008] S3. Take the upwind region equilibrium induced wind speed as the inflow wind speed of the drag rotor region, and calculate the equilibrium induced wind speed in the drag rotor influence region and the aerodynamic performance of the drag rotor region;

[0009] S4. Take the upwind region equilibrium induced wind speed outside the influence region and the equilibrium induced wind speed in the drag rotor influence region as the inflow wind speed of the downwind region lift rotor, and calculate the aerodynamic performance of the downwind region lift rotor;

[0010] S5. Obtain the aerodynamic performance of the dual-rotor power device according to the aerodynamic performance of the upwind region lift rotor, the aerodynamic performance of the drag rotor region and the aerodynamic performance of the downwind region lift rotor.

[0011] An embodiment of the present invention provides a pneumatic evaluation system for a compound dual-rotor power device, including:

[0012] A data acquisition module for obtaining the rotor data and wind field data of the dual-rotor power device;

[0013] An upwind region aerodynamic performance module for calculating the aerodynamic performance of the upwind region lift rotor and the upwind region equilibrium induced wind speed according to the data obtained by the data acquisition module;

[0014] A drag rotor region performance module for taking the upwind region equilibrium induced wind speed as the inflow wind speed of the drag rotor region and calculating the equilibrium induced wind speed in the drag rotor influence region and the aerodynamic performance of the drag rotor region;

[0015] A downwind region aerodynamic performance module for taking the upwind region equilibrium induced wind speed outside the influence region and the equilibrium induced wind speed in the drag rotor influence region as the inflow wind speed of the downwind region lift rotor and calculating the aerodynamic performance of the downwind region lift rotor;

[0016] An overall aerodynamic performance module for obtaining the aerodynamic performance of the dual-rotor power device according to the aerodynamic performance of the upwind region lift rotor, the aerodynamic performance of the drag rotor region and the aerodynamic performance of the downwind region lift rotor.

[0017] An embodiment of the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the steps of the pneumatic evaluation method for a compound dual-rotor power device.

[0018] An embodiment of the present invention provides a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of the method such as the pneumatic evaluation method for a compound dual-rotor power device.

[0019] By adopting the embodiment of the present invention, the aerodynamics of a dual-rotor power device is obtained by acquiring the aerodynamic performance of the upstream lift rotor, the aerodynamic performance of the drag rotor area, and the aerodynamic performance of the downstream lift rotor, realizing fast and effective aerodynamic evaluation, which is of great significance for the design and application of such rotor devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in one or more embodiments of the present specification or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present specification. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 It is a schematic diagram of the pneumatic evaluation method for a compound dual-rotor power device according to an embodiment of the present invention;

[0022] Figure 2 It is a schematic diagram of a Savonius and Darrieus composite rotor device according to an embodiment of the present invention;

[0023] Figure 3 It is a specific structural schematic diagram of a Savonius and Darrieus composite rotor device according to an embodiment of the present invention;

[0024] Figure 4 It is a schematic diagram of the pneumatic evaluation model for a compound dual-rotor power device of the present invention;

[0025] Figure 5 It is a schematic diagram of the influence area of the drag rotor wind field of the present invention;

[0026] Figure 6 It is a schematic diagram of the structural dimensions of a 1kW lift-drag compound rotor device of the present invention;

[0027] Figure 7 It is the relationship between the velocity induction factor and height when not considering the action of the drag rotor of the present invention;

[0028] Figure 8 When introducing the drag rotor for the present invention, the relationship between the velocity induction factor and height

[0029] Figure 9 It is a calculation and test comparison chart of the overall power of the compound dual-rotor power device of the present invention. Specific embodiments

[0030] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the following will clearly and completely describe the technical solutions in one or more embodiments of this specification with reference to the accompanying drawings in one or more embodiments of this specification. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this document.

[0031] Method embodiments

[0032] An embodiment of the present invention provides a method for aerodynamic evaluation of a compound dual-rotor power device, Figure 1 It is a schematic diagram of the method for aerodynamic evaluation of the compound dual-rotor power device according to the embodiment of the present invention. According to Figure 1 As shown, the method for aerodynamic evaluation of the compound dual-rotor power device according to the embodiment of the present invention includes:

[0033] S1. Obtain the rotor data and wind field data of the dual-rotor power device;

[0034] S2. Calculate the aerodynamic performance of the upper wind area lift rotor and the balanced induced wind speed in the upper wind area according to the data obtained in step S1;

[0035] S3. Take the balanced induced wind speed in the upper wind area as the inflow wind speed of the drag rotor area, and calculate the balanced induced wind speed in the drag rotor influence area and the aerodynamic performance of the drag rotor area;

[0036] S4. Take the balanced induced wind speed in the upper wind area outside the influence area and the balanced induced wind speed in the drag rotor influence area as the inflow wind speed of the lower wind area lift rotor, and calculate the aerodynamic performance of the lower wind area lift rotor;

[0037] S5. Obtain the aerodynamic performance of the dual-rotor power device according to the aerodynamic performance of the upper wind area lift rotor, the aerodynamic performance of the drag rotor area, and the aerodynamic performance of the lower wind area lift rotor.

[0038] According to Figure 1 It can be known that step S2 of the embodiment of the present invention specifically includes:

[0039] a. Set the initial value of the induction factor a;

[0040] b. Calculate the angle of attack, relative wind speed, and Reynolds number of the blade element;

[0041] c. Obtain the lift - drag characteristics of the airfoil based on the angle of attack and Reynolds number;

[0042] d. Iteratively solve for the new induced coefficient a1 according to the local blade element load and the flow - tube flow - direction force;

[0043] e. Determine the relationship between the difference between a1 and a and the given residual. If it is less than the residual, the iteration stops; otherwise, the iteration continues.

[0044] Step S3 of the embodiment of the present invention specifically includes:

[0045] a. Calculate the force on the drag - type rotor blade and the average power;

[0046] b. Calculate the power change of the momentum of each flow - tube in the drag - type rotor area;

[0047] c. Calculate the velocity induction factor b in the drag - type rotor area.

[0048] Step S4 of the embodiment of the present invention specifically includes:

[0049] a. Calculate the oncoming wind field of the blades in the downwind area;

[0050] b. Set the initial value of the induction factor a';

[0051] c. Calculate the angle of attack, relative wind speed, and Reynolds number of the blade element;

[0052] d. Obtain the lift - drag characteristics of the airfoil based on the angle of attack and Reynolds number;

[0053] e. Iteratively solve for the new induced coefficient a1' according to the local blade element load and the flow - tube flow - direction force;

[0054] f. Determine the relationship between the difference between a' and a1' and the given residual. If it is less than the residual, the iteration stops; otherwise, the iteration continues.

[0055] Figure 2 is a schematic diagram of the Savonius - Darrieus composite rotor device of the embodiment of the present invention. The Savonius - type rotor device has a simple structure and is easy to start, but has low efficiency. The Darrieus - type rotor device has a large tip - speed ratio and high wind - energy utilization rate, but has poor starting performance. In order to improve the starting performance of the Darrieus - type rotor device, the Savonius - type rotor and the Darrieus - type rotor are combined, and a compound dual - rotor power device with a drag - cup structure is proposed, which can greatly expand the application range of the vertical - axis rotor device.

[0056] Figure 3 is a specific structural schematic diagram of the Savonius - Darrieus composite rotor device of the embodiment of the present invention, Figure 4Schematic diagram of the pneumatic evaluation model of the compound dual-rotor power device according to an embodiment of the present invention. A resistance rotor region is introduced between the two actuating disks. It is considered that the influence of the resistance rotor region on the upper-wind region rotor is relatively small and can be ignored. The balanced induced wind speed generated in the upper-wind region is the incoming wind speed of the resistance rotor region.

[0057] Figure 5 Schematic diagram of the influence region of the resistance rotor wind field according to an embodiment of the present invention. As Figure 5 shown, the resistance rotor mainly affects the lift rotor blades in the downwind region, and the influence region on the wind field is in the height section where it is located, that is, z sd ~z su section. Considering the rotation of the wind turbine, it is considered that the flow field in this height section is the action region of the resistance rotor throughout the entire circumference. When calculating, the flow tube between the lift rotor and the resistance rotor is corresponding according to the phase angle relationship. At the same time, for the convenience of calculation, it is considered that the influence of the resistance rotor on the downwind region is uniform.

[0058] The radius of the resistance rotor is R s , V e1 is the balanced wind speed after the upper-wind region, V e2 is the balanced wind speed after the resistance rotor region, ω is the blade rotation angular velocity, F d1 and F d2 are the resistances generated by the concave and convex blades respectively. Due to the symmetry of the resistance rotor blades, the average power of the blade rotating 180° can be calculated as the average power during the operation of the rotor device as the average power during the operation of the resistance rotor. At a height of z and a phase angle of θ, the average velocity of the resistance blade unit is:

[0059] u = ωR s (1 - cos2θ)

[0060]

[0061]

[0062] where A sm is the projected area of the blade unit,

[0063] A sm = dh * ΔR s = dh * 2R s |sin 2 (θ + Δθ / 2) - sin 2 (θ - Δθ / 2)

[0064] The net thrust and work of the resistance rotor blade unit are:

[0065] F d = F d1 - F d2

[0066]

[0067] The average power is: P = W / T, where T is the time taken for the rotor to rotate 180°. Referring to the idea of establishing the multi-streamtube model, it is considered that the average power of the drag rotor calculated from the fluid resistance should be equal to the power brought about by the change in momentum of each streamtube passing through the drag rotor area. Introduce the velocity induction factor b in the drag rotor area. The velocity relationship of each part in the streamtube in the influence area of the drag rotor at a height of z and a phase angle of θ is as follows:

[0068] V s = bV e1

[0069] V e2 = (2b - 1)V e1

[0070] Neglecting the expansion of the streamtube when passing through the rotor, the cross-sectional area A per unit height of the streamtube in the upwind and downwind areas su = A sd = rΔθdzcosθ, the momentum and average power of the streamtube:

[0071]

[0072]

[0073] The interference factor b in the drag rotor area

[0074]

[0075] For the area outside the height of the drag rotor and not affected by it,

[0076] V e2 = V e1

[0077] Thus, the oncoming flow velocity field of the lift rotor in the downwind area is obtained. After obtaining the velocity induction factor in the downwind area through iteration, by synthesizing the aerodynamic loads in the upwind area of the lift rotor and the drag rotor area, the aerodynamic performance of the entire rotor device can be obtained.

[0078] Figure 6 For a 1 kW-class lift-drag compound rotor device, the aerodynamic analysis is carried out using the aerodynamic evaluation method provided by the present invention. The rotor device consists of a lift rotor and a drag rotor. The lift rotor uses 3 semi-circular blades with a radius R d = 0.8 m, and the blade section is the NACA0018 airfoil with a chord length c = 0.12 m. The drag rotor uses a double-layer structure, and the radius of the semi-circular blade of the drag rotor is R s = 0.1 m, and the single-layer height is 0.3 m.

[0079] Figure 7 For the variation relationship of the velocity induction factor with height when not considering the influence of the drag rotor, the variation relationships of the velocity induction factors a and a' in the upwind and downwind regions with the relative height are given. It can be seen that the velocity induction factor near the equatorial plane of the lift rotor is relatively small. As the relative height increases, that is, the distance of the blade from the equatorial plane increases, the velocity induction factor increases. This reflects that the power of the lift rotor is mainly provided by the blades near the equatorial plane. At the same time, at the same height, the velocity induction factor in the downwind region is smaller than that in the upwind region, and it is considered that this difference is mainly caused by the difference in the local oncoming wind speed.

[0080] Figure 8 For the variation relationship of the velocity induction factor with height when introducing the drag rotor, it can be seen that the overall variation trend of the velocity induction factor is the same as that when not considering the drag rotor. Among them, the induction factor a in the upwind region is basically the same in both cases, but the velocity induction factor a' in the downwind region of the compound rotor device is significantly smaller than that when not considering the drag rotor. It is considered that this is mainly because the drag rotor further decelerates the oncoming flow in its influence area, resulting in a smaller oncoming wind speed in the downwind region.

[0081] Figure 9 For the calculation and test comparison diagram of the overall power of the compound dual-rotor power device, the settlement results obtained by using the aerodynamic evaluation model of the compound dual-rotor power device established by the present invention are in good agreement with the test results, and the aerodynamic evaluation model can basically reflect the variation trend of the power of the compound rotor device with the wind speed.

[0082] For the aerodynamic evaluation method of the compound dual-rotor power device provided by the embodiment of the present invention, after obtaining the basic parameters of the rotor and the wind field, the velocity field of the upwind lift rotor is solved and used as the inflow wind speed of the drag rotor area. For the downwind lift rotor, its oncoming wind speed mainly includes two parts, the balanced induced wind speed in the influence area of the drag rotor and the balanced induced wind speed from the upwind area outside the influence area.

[0083] Compared with the horizontal axis rotor device and the H-type Darrieus rotor device, the Φ-type Darrieus rotor device with curved blades has obvious aerodynamic unsteady characteristics. After forming a composite structure with the Savonius rotor, the unsteadiness of the flow field is further enhanced. The steady CFD method and the quasi-steady CFD method including the MRF model generally cannot provide reliable numerical solutions for the compound vertical axis rotor device, and the unsteady CFD method requires a large amount of computing resources. The test method has a high cost and a long cycle. The aerodynamic evaluation model of the compound dual-rotor power device provided by the present invention can achieve fast and effective aerodynamic evaluation by using a relatively reliable engineering method, which has important significance for the design and application of such rotor devices.

[0084] System embodiment

[0085] An aerodynamic evaluation system for a compound dual-rotor power device according to an embodiment of the present invention is characterized by comprising:

[0086] A data acquisition module for acquiring rotor data and wind field data of the dual-rotor power device;

[0087] An upper wind region aerodynamic performance module for calculating the aerodynamic performance of the lift rotor in the upper wind region and the equilibrium induced wind speed in the upper wind region according to the data acquired by the data acquisition module;

[0088] A drag rotor region performance module for using the equilibrium induced wind speed in the upper wind region as the inflow wind speed of the drag rotor region to calculate the equilibrium induced wind speed in the drag rotor influence region and the aerodynamic performance of the drag rotor region;

[0089] A lower wind region aerodynamic performance module for using the equilibrium induced wind speed in the upper wind region outside the influence region and the equilibrium induced wind speed in the drag rotor influence region as the inflow wind speed of the lift rotor in the lower wind region to calculate the aerodynamic performance of the lift rotor in the lower wind region;

[0090] An overall aerodynamic performance module for obtaining the aerodynamic performance of the dual-rotor power device according to the aerodynamic performance of the lift rotor in the upper wind region, the aerodynamic performance of the drag rotor region, and the aerodynamic performance of the lift rotor in the lower wind region.

[0091] The upper wind region aerodynamic performance module is specifically used for:

[0092] Setting an upper wind region induction factor a and presetting an initial value of a;

[0093] Calculating the angle of attack, relative wind speed, and Reynolds number of the blade elements in the upper wind region;

[0094] Obtaining the lift-drag characteristics of the airfoil in the upper wind region according to the angle of attack and Reynolds number, and obtaining the equilibrium induced wind speed in the upper wind region according to the relative wind speed;

[0095] Iteratively solving a new upper wind region induction factor according to the local blade element load in the upper wind region and the flow tube flow force in the upper wind region;

[0096] Determining the relationship between the difference between the new upper wind region induction factor and the preset initial value of a and a predetermined residual. If the difference is less than the predetermined residual, the iteration stops; otherwise, continue the iteration step to solve the new upper wind region induction factor.

[0097] The drag rotor region performance module is specifically used for:

[0098] Setting a drag rotor region induction factor b and presetting an initial value of b;

[0099] Calculating the average power of the drag rotor blades and the power change of the momentum of each flow tube in the drag rotor region according to the initial value of b;

[0100] Iteratively solve for the new induced factor in the drag rotor region based on the average power of the drag rotor blades and the power change of the momentum of each flow tube in the drag rotor region;

[0101] Determine the relationship between the difference between the new induced factor in the drag rotor region and the initial value of the preset b and the predetermined residual. If the difference is less than the predetermined residual, the iteration stops; otherwise, continue to iteratively solve for the new induced factor in the drag rotor region.

[0102] The aerodynamic performance module in the downwind region is specifically used for:

[0103] Calculate the oncoming wind field of the blades in the downwind region based on the balanced induced wind speed in the upwind region and the balanced induced wind speed in the drag rotor influence region;

[0104] Set the induced factor a' in the downwind region and preset the initial value of a';

[0105] Calculate the angle of attack, relative wind speed, and Reynolds number of the blade elements in the downwind region;

[0106] Obtain the lift-drag characteristics of the airfoil in the downwind region based on the angle of attack and Reynolds number in the downwind region;

[0107] Iteratively solve for the new induced factor in the downwind region based on the local blade element load in the downwind region and the flow tube flow direction force in the downwind region;

[0108] Determine the relationship between the difference between the induced factor a' in the downwind region and the induced factor in the downwind region and the given residual. If the difference is less than the residual, the iteration stops; otherwise, iteratively solve for the new induced factor in the downwind region.

[0109] Device Embodiment 1

[0110] An embodiment of the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor, when executing the computer program, implements the steps of the above method embodiment.

[0111] Device Embodiment 2

[0112] A computer-readable storage medium stores a computer program, and the computer program, when executed by a processor, implements the steps of the above method embodiment.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features. However, such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pneumatic evaluation method for a compound dual-rotor power device, characterized in that, Including: S1. Obtain the rotor data and wind field data of the dual-rotor power device; S2. Calculate the aerodynamic performance of the upwind region lift rotor and the upwind region equilibrium induced wind speed according to the data obtained in step S1; S3. Take the upwind region equilibrium induced wind speed as the inflow wind speed of the drag rotor region, and calculate the equilibrium induced wind speed of the drag rotor influence region and the aerodynamic performance of the drag rotor region; S4. Take the upwind region equilibrium induced wind speed outside the influence region and the equilibrium induced wind speed of the drag rotor influence region as the inflow wind speed of the downwind region lift rotor, and calculate the aerodynamic performance of the downwind region lift rotor; S5. Obtain the aerodynamic performance of the dual-rotor power device according to the aerodynamic performance of the upwind region lift rotor, the aerodynamic performance of the drag rotor region, and the aerodynamic performance of the downwind region lift rotor; The specific steps of step S3 include: S31. Set the induction factor b of the drag rotor region and preset the initial value of b; S32. Calculate the average power of the drag rotor blades and the momentum change power of each stream tube in the drag rotor region according to the initial value of b; S33. Iteratively solve the new induction factor of the drag rotor region according to the average power of the drag rotor blades and the momentum change power of each stream tube in the drag rotor region; S34. Determine the relationship between the difference between the new induction factor of the drag rotor region and the preset initial value of b and the predetermined residual. If the difference is less than the predetermined residual, the iteration stops; otherwise, continue to iterate step S33; The specific steps of step S4 include: S41. Calculate the incoming wind field of the downwind region blades according to the upwind region equilibrium induced wind speed and the equilibrium induced wind speed of the drag rotor influence region; S42. Set the induction factor for the downwind area , and preset the initial value; S43. Calculate the angle of attack, relative wind speed and Reynolds number of the downwind region blade elements; S44. Obtain the lift-drag characteristics of the downwind region airfoil according to the downwind region angle of attack and Reynolds number; S45. Iteratively solve the new downwind region induction factor according to the local blade element load in the downwind region and the stream tube flow direction force in the downwind region; S46. Determine the downwind area induction factor The relationship between the difference from the downwind area induction factor and the given residual. If the difference is less than the residual, the iteration stops; otherwise, step S45 is iteratively executed.

2. The method according to claim 1, characterized in that The specific steps of step S2 include: S21. Set the induction factor of the upper wind area , and preset the initial value; S22. Calculate the angle of attack, relative wind speed and Reynolds number of the upwind region blade elements; S23. Obtain the lift-drag characteristics of the upwind region airfoil according to the angle of attack and Reynolds number, and obtain the upwind region equilibrium induced wind speed according to the relative wind speed; S24. Iteratively solve the new upwind region induction factor according to the local blade element load in the upwind region and the stream tube flow direction force in the upwind region; S25. Determine the relationship between the difference between the new upwind area induction factor and the preset initial value and the predetermined residual. If the difference is less than the predetermined residual, the iteration stops; otherwise, continue with iteration step S24.

3. A pneumatic evaluation system for a compound dual-rotor power device, characterized in that, Including: A data acquisition module for obtaining the rotor data and wind field data of the dual-rotor power device; An upwind region aerodynamic performance module for calculating the aerodynamic performance of the upwind region lift rotor and the upwind region equilibrium induced wind speed according to the data obtained by the data acquisition module; A drag rotor region performance module for taking the upwind region equilibrium induced wind speed as the inflow wind speed of the drag rotor region and calculating the equilibrium induced wind speed of the drag rotor influence region and the aerodynamic performance of the drag rotor region; A downwind region aerodynamic performance module for taking the upwind region equilibrium induced wind speed outside the influence region and the equilibrium induced wind speed of the drag rotor influence region as the inflow wind speed of the downwind region lift rotor and calculating the aerodynamic performance of the downwind region lift rotor; An overall aerodynamic performance module for obtaining the aerodynamic performance of the dual-rotor power device according to the aerodynamic performance of the upwind region lift rotor, the aerodynamic performance of the drag rotor region, and the aerodynamic performance of the downwind region lift rotor; The drag rotor region performance module is specifically used for: Set the induction factor b of the resistance rotor region and preset the initial value of b; Calculate the average power of the resistance rotor blades and the power change of the momentum of each flow tube in the resistance rotor region according to the initial value of b; Iteratively solve for the new induction factor of the resistance rotor region based on the average power of the resistance rotor blades and the power change of the momentum of each flow tube in the resistance rotor region; Determine the relationship between the difference between the new induction factor of the resistance rotor region and the preset initial value of b and the predetermined residual. If the difference is less than the predetermined residual, the iteration stops; otherwise, continue to iteratively solve for the new induction factor of the resistance rotor region; The downwind region aerodynamic performance module is specifically used for: Calculate the oncoming flow wind field of the downwind region blades according to the balanced induced wind speed in the upwind region and the balanced induced wind speed in the resistance rotor influence region; Set the induction factor in the downwind area , and preset the initial value; Calculate the angle of attack, relative wind speed, and Reynolds number of the downwind region blade elements; Obtain the lift-drag characteristics of the downwind region airfoil according to the angle of attack and Reynolds number in the downwind region; Iteratively solve for the new induction factor of the downwind region based on the local blade element load in the downwind region and the flow tube flow direction force in the downwind region; Determine the induction factor in the downwind area The relationship between the difference of the induction factor in the downwind area and the given residual. If the difference is less than the residual, the iteration stops; otherwise, a new induction factor in the downwind area is iteratively solved.

4. The system according to claim 3, characterized in that, The upwind region aerodynamic performance module is specifically used for: Set the induction factor for the upwind area , and preset initial value; Calculate the angle of attack, relative wind speed, and Reynolds number of the upwind region blade elements; Obtain the lift-drag characteristics of the upwind region airfoil according to the angle of attack and Reynolds number, and obtain the balanced induced wind speed in the upwind region according to the relative wind speed; Iteratively solve for the new induction factor of the upwind region based on the local blade element load in the upwind region and the flow tube flow direction force in the upwind region; Determine the relationship between the difference between the newly determined upwind region induction factor and the preset initial value and the predetermined residual. If the difference is less than the predetermined residual, the iteration stops; otherwise, continue with the iteration step to solve for the new upwind region induction factor.

5. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, the steps described in the aerodynamic evaluation method of the compound dual-rotor power device according to any one of claims 1 to 2 are implemented.

6. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, the steps described in the aerodynamic evaluation method of the compound dual-rotor power device according to any one of claims 1 to 2 are implemented.

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