Rocket boosting type glider design method

Abstract

The invention provides a rocket boosting type glider design method, and relates to the technical field of gliders, the rocket boosting type glider design method comprises the steps of wing selection, main wing size determination, gravity center design position calculation, main wing mass calculation, empennage mass calculation, installation position calculation and glider flight performance checking calculation, and the wing extension formula for main wing size determination is lambda = l / b, the gravity center position of the gravity center design position is located at the 1 / 3 wing width position away from the front edge of the wing, and the mass of the main wing, the mass of the empennage and the mounting position are determined while the gravity center design position is determined. The method is a complete method from wing size to final finished product flight verification, the design threshold of the rocket-assisted glider is greatly reduced, formula calculation cooperation is achieved in all stages, various modification work when real object components of the rocket-assisted glider are unreasonable is reduced, and the design efficiency of the rocket-assisted glider is improved. The problems that the test manufacturing cost of the rocket boosting type glider is greatly increased, and the performance consistency of each batch of a traditional rocket boosting type glider is difficult to guarantee are solved.

Description

Technical Field

[0001] The invention relates to the technical field of gliders, and in particular to a design method for a rocket-assisted glider. Background Art

[0002] A rocket-assisted glider is an aircraft that organically combines a model rocket with a glider. The continuous advancement of rocket technology provides a power basis for it. Model rocket engines can provide powerful thrust, allowing the glider to quickly reach a certain height and speed and enter the gliding stage. In order to obtain greater lift, traditional fixed-wing rocket-assisted gliders generally have a large wingspan, occupy a large space, and are inconvenient to carry. Therefore, we use a folding wing design to ensure that the wing obtains greater lift while reducing the space occupied by the aircraft and improving space utilization.

[0003] The design of folding wings increases the complexity of rocket-assisted gliders, and the design difficulty of rocket-assisted gliders increases. The traditional process of manufacturing, test flying, and then adjusting and improving the folding wings is more prone to wear and tear, which requires the entire machine to be remanufactured. The number of manufacturing and testing of rocket-assisted gliders has increased significantly, and the test and manufacturing costs of rocket-assisted gliders have increased significantly, and it is difficult to ensure the consistency of performance of each batch of traditional rocket-assisted gliders. Summary of the invention

[0004] The disclosed embodiments relate to a method for designing a rocket-propelled glider, a complete method from wing size to final flight verification of the finished product, which greatly reduces the design threshold of the rocket-propelled glider. Formula calculations are used in each stage, and the design can begin without the need for physical coordination, which is a good connection between theory and practice. After the theory is reasonable, the components of the physical glider can be started, and various modifications when the physical components of the rocket-propelled glider are unreasonable can be reduced. The test manufacturing cost and the number of tests for various verification tests of the rocket-propelled glider can be reduced, thereby ensuring the consistency of performance of each batch of traditional rocket-propelled gliders.

[0005] In a first aspect, the present disclosure provides a method for designing a rocket-assisted glider, which specifically includes: wing selection, main wing size determination, center of gravity design position, main wing mass, tail wing mass and installation position, and glider flight performance verification. The basic constituent materials of the rocket-assisted glider include auxiliary ABS injection-molded structural parts, GPI materials, carbon fiber rods, wire pull rods, servos, batteries, and rubber bands. Wing selection: The lift of the wing comes from the pressure difference between the upper and lower surfaces of the wing caused by airflow. The cross-sectional shape of the wing - the airfoil - has a great influence on the size of the pressure difference between the upper and lower surfaces of the wing caused by airflow and its own resistance. This influence is the aerodynamic performance of the airfoil. The size of the flight lift of the glider depends on the design of the wing airfoil. The flat-convex aileron can better provide lift for the glider.

[0006] In at least some embodiments, the wing is selected as a flat-convex aileron, which can provide better lift for the glider. The main work in the main wing size determination stage is the principle / span ratio / required size. The suitable wing span ratio λ is between 7 and 9. Then, the wing span formula in the main wing size determination is obtained: λ = l / b (l is the wing span; b is the mean chord length). The design size table of the main wing is given (attached Figure 3 ).

[0007] In at least some embodiments, to determine whether the glider meets the longitudinal and lateral stability, the wing area Aw can be used as a reference plane. At this time, the horizontal tail area At should be 0.25 - 0.35Aw to ensure the longitudinal stability of the glider. The geometric shape of the glider can be defined by introducing a dimensionless coefficient - the horizontal tail coefficient CTH. The formula is used to calculate the longitudinal stability. The geometric shape of the glider is defined by the horizontal tail coefficient CTH, with the wing area Aw as the reference plane. At this time, the horizontal tail area At should be 0.25 - 0.35Aw to ensure the longitudinal stability of the glider. In the formula is the distance from 1 / 4 of the mean aerodynamic chord length behind the wing to 1 / 4 of the mean aerodynamic chord length in front of the horizontal tail; Cw is the mean aerodynamic chord length of the wing, obtained by wing area / wing span. When 0.8 < CTH < 1.25, the longitudinal stability of the glider can be ensured;

[0008] Similarly, by introducing the vertical tail coefficient , the main wing size is determined by the formula to calculate the lateral and transverse stability. In the formula, Af is the vertical tail area, and its value should be 0.05 - 0.15Aw. When 0.15 < CTV < 0.45, the glider can be ensured to have lateral and transverse stability.

[0009] In at least some embodiments, the designed position of the center of gravity directly affects the flight stability of the glider. By taking the moment about the front end of the nose, from the resultant moment balance formula, it can be obtained that: the moment of the whole machine = the moment of the fuselage + the moment of the main wing + the moment of the tail wing = the gravity of the whole machine multiplied by the distance from the center of gravity of the whole machine to the front end of the nose. The moment of the fuselage = the gravity of the fuselage multiplied by the distance from the center of gravity of the fuselage to the front end of the nose; the moment of the main wing = the gravity of the main wing multiplied by the distance from the center of gravity of the main wing to the front end of the nose; the moment of the tail wing = the gravity of the tail wing multiplied by the distance from the center of gravity of the tail wing to the front end of the nose; finally, the designed position of the center of gravity of the whole machine is determined. For a flat-convex wing, according to the above center of gravity allocation formula, the center of gravity position should be designed to fall at the position of 1 / 3 of the wing width from the leading edge of the wing. When the designed position of the center of gravity is determined, the mass of the main wing, the mass of the tail wing, and the installation position are also determined;

[0010] In at least some embodiments, the glider flight performance verification is a computational verification work for three stages: boost stage, glide stage and gliding stage;

[0011] According to Newton's second law, the differential equation of motion of the rocket-assisted glider during the boost phase is obtained:

[0012] (1)

[0013] Where, T is the average thrust of the rocket engine; m is the mass of the glider; are the velocity components of the glider in the horizontal and vertical directions respectively; t is the time; D is the air resistance of the glider, which are calculated according to the following formulas:

[0014] (2)

[0015] In the formula, are the drag coefficient, air density and wing area of ​​the glider respectively.

[0016] According to the initial condition, the velocity is zero, the launch angle and thrust are known, and the acceleration at the initial moment can be calculated according to the formula. Divide the thrust action time into n equal parts. As long as n is large enough, each equal time period can be approximately regarded as a uniformly accelerated motion. Therefore, according to the initial conditions, the velocity, displacement and acceleration at the next moment can be calculated. The calculation formula is as follows:

[0017] The angle between the glider's flight direction and the horizontal , can be calculated as follows:

[0018] (3)

[0019] (4)

[0020] (5)

[0021] Where dt is the time step. Based on the above formula, the process is implemented through MATLAB programming, and finally the data of the boosting stage can be obtained.

[0022] In at least some embodiments, according to Newton's second law, the equation of motion for the gliding phase is

[0023] (6)

[0024] The solution process is the same as that of the boost phase, and its initial conditions are the displacement and velocity at the end of the boost phase. The gliding phase is based on the vertical velocity component of the glider during its ascent. Zero is used as the end mark.

[0025] In at least some embodiments, according to Newton's second law, the equation of motion for the gliding phase is

[0026] (7)

[0027] in, is the air lift, which is calculated as follows:

[0028] (8)

[0029] In the formula, is the lift coefficient.

[0030] The initial conditions are the displacement and velocity at the end of the gliding phase. The solution is similar to that of the boost phase and will not be listed here.

[0031] The present invention provides a rocket-assisted glider design method, which has the following beneficial effects:

[0032] This design method is a complete method from wing size to final product flight verification, which greatly reduces the design threshold of rocket-assisted gliders. Formula calculations are used in each stage, and design can begin without physical coordination. It is a good connection between theory and practice. After the theory is reasonable, the components of the physical glider can be started, which reduces various modifications when the physical components of the rocket-assisted glider are unreasonable, and reduces the test manufacturing cost and test frequency of various verification tests of the rocket-assisted glider.

[0033] This design method is a systematic and step-by-step design method. It conducts design verification through glider flight performance verification, realizes virtual verification of glider flight, reduces the number of damages caused by physical verification flight accidents of rocket-assisted gliders, further reduces the flight verification cost of rocket-assisted gliders, and ensures the consistency of performance of each batch of traditional rocket-assisted gliders. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings of the embodiment are briefly introduced below.

[0035] The drawings described below are only related to some embodiments of the present invention, but are not intended to limit the present invention.

[0036] In the attached picture:

[0037] Figure 1 A schematic diagram showing the flow of the design method of the present application is shown;

[0038] Figure 2 A cross-sectional view of a plano-convex aileron airfoil of the present application is shown;

[0039] Figure 3 The main wing design dimension table of the present application is shown;

[0040] Figure 4 The tail wing size design table of the present application is shown;

[0041] Figure 5 The stability calculation table of the present application is shown;

[0042] Figure 6 A schematic diagram showing the main wing mass and tail wing mass dimensions of the present application is shown;

[0043] Figure 7 The simplified calculation diagram and load analysis diagram of the glider in the boost phase of the present application are shown;

[0044] Figure 8 The simplified calculation diagram and load analysis diagram of the glider in the gliding phase of the present application are shown;

[0045] Fig. 9 The schematic diagram of the glider calculation and load analysis in the gliding phase of the present application is shown;

[0046] Fig.10 A graph showing the relationship between horizontal speed and flight time of the present application is shown;

[0047] Fig.11 A graph showing the relationship between vertical speed and flight time of the present application is shown;

[0048] Fig.12 A graph showing the relationship between the flight altitude and the flight time of the present application is shown;

[0049] Fig.13 A graph showing the relationship between horizontal distance and flight altitude of the present application is shown;

[0050] Fig.14 A graph showing the relationship between horizontal distance and flight time of the present application is shown.

[0051] Reference numerals list

[0052] 1. Wing selection;

[0053] 2. Determine the size of the main wing;

[0054] 3. Center of gravity design position;

[0055] 4. Main wing mass, tail wing mass and installation position;

[0056] 5. Verification of glider flight performance; 501. Boost phase; 502. Glide phase; 503. Glide phase. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] Example 1: Please refer to Figures 1 to 14 :

[0059] The invention proposes a design method for a rocket-assisted glider, comprising: wing selection 1, main wing size determination 2, center of gravity design position 3, main wing mass, tail wing mass and installation position 4 and glider flight performance verification 5. The basic constituent materials of the rocket-assisted glider include auxiliary ABS injection molding structural parts, GPI materials, carbon fiber rods, steel wire pull rods, steering gears, batteries and rubber bands. Wing selection 1: The lift of the wing comes from the pressure difference between the upper and lower surfaces of the wing caused by airflow. The cross-sectional shape of the wing, i.e., the airfoil, has a great influence on the size of the pressure difference between the upper and lower surfaces of the wing caused by airflow and its own resistance. This influence is the aerodynamic performance of the airfoil. The flight lift of the glider depends on the design of the wing airfoil. The flat-convex aileron can provide lift for the glider better.

[0060] Wing selection 1 is a flat-convex aileron, which can provide lift for the glider better. The main work of the second stage of determining the size of the main wing is principle / aspect ratio / required size. Since the airflow in the air is composed of countless fluid micro-groups, and the fluid micro-groups can be regarded as countless streamlines, the streamline is the path through which the fluid micro-groups flow. According to the continuity principle of airflow, the fluid is incompressible and can only flow in the channel. The mass of the fluid passing through any interface on the channel in unit time is equal. We can get the following conclusions by applying the continuity principle to the analysis of the wing: the narrower the cross section, the denser the streamline, resulting in faster flow, and vice versa, the slower the flow; when the loaded glider flies in the air, it needs enough lift to maintain the flight state, which mainly uses the pressure difference between the upper and lower surfaces when the object moves to generate lift. The greater the pressure difference between the upper and lower surfaces, the greater the lift generated. The speed of air flowing over the upper surface of the wing is relatively large, while the speed of air flowing over the lower surface is relatively small, so low pressure is generated on the upper surface of the wing and high pressure is generated on the lower surface, so the wing generates a lift; under the premise of a certain lift, a thin and long wing has less resistance than a short and wide wing. This is the result of the three-dimensional effect of the wing caused by fluid adhesion. According to the information, the suitable wing aspect ratio λ is between 7-9, and then the wing span formula in the main wing size determination 2 is obtained: λ=l / bl-wing span; b-average chord length, and the main wing design size table is given in the attachment Figure 3, if an aircraft can return to its original state before being disturbed after being disturbed, the aircraft is said to be stable during flight; otherwise, the aircraft is in an unstable state. Therefore, roll and pitch stability need to be considered during design. The roll and pitch stability of a glider are related to the dihedral angle of the wing and the relative positions of the center of gravity and the center of pressure of the glider.

[0061] The relative position of the center of gravity of the glider and the center of pressure of the wing has a great influence on the longitudinal stability. When the aircraft is disturbed, the angle of attack of the aircraft changes, and the change in the lift generated by the horizontal tail and the wing forms a restoring moment on the center of gravity, while maintaining the longitudinal stability of the aircraft as much as possible while obtaining lift.

[0062] To determine whether a glider meets the longitudinal and lateral stability requirements, the wing area Aw can be used as a reference surface. At this time, the horizontal tail area At should be 0.25 - 0.35Aw to ensure the longitudinal stability of the glider. The geometric shape of the glider can be defined by introducing a dimensionless coefficient - the horizontal tail coefficient CTH. The formula To calculate the longitudinal stability, the geometric shape of the glider is defined by the horizontal tail coefficient CTH. Using the wing area Aw as the reference surface, the horizontal tail area At should be 0.25 - 0.35Aw at this time to ensure the longitudinal stability of the glider. In the formula is the distance from 1 / 4 of the mean aerodynamic chord length behind the wing to 1 / 4 of the mean aerodynamic chord length in front of the horizontal tail; Cw is the mean aerodynamic chord length of the wing, which is obtained by wing area / wingspan. When 0.8 < CTH < 1.25, the longitudinal stability of the glider can be ensured;

[0063] By the same token, the vertical tail coefficient is introduced. The main wing size is determined by the formula to calculate the lateral and transverse stability. In the formula, Af is the vertical tail area, and its value should be 0.05 - 0.15Aw. When 0.15 < CTV < 0.45, the glider can be ensured to have lateral and transverse stability. According to the stability calculation, the size of the tail is designed, as shown in Appendix Figure 4 and Appendix Figure 5 shown.

[0064] The design position of the center of gravity 3 directly affects the flight stability of the glider. The moment is taken at the front end of the nose. From the formula for the balance of combined moments, we can get: the moment of the whole machine = the moment of the fuselage + the moment of the main wing + the moment of the tail wing = the weight of the whole machine multiplied by the distance from the center of gravity of the whole machine to the front end of the nose. The moment of the fuselage = the weight of the fuselage multiplied by the distance from the center of gravity of the fuselage to the front end of the nose; the moment of the main wing = the weight of the main wing multiplied by the distance from the center of gravity of the main wing to the front end of the nose; the moment of the tail wing = the weight of the tail wing multiplied by the distance from the center of gravity of the tail wing to the front end of the nose. Finally, the design position of the center of gravity 3 of the whole machine is determined. For plano-convex wings, according to the above-mentioned center of gravity adjustment formula, the center of gravity should be designed to fall at a position 1 / 3 of the wing width from the leading edge of the wing. When the design position of the center of gravity 3 is determined, the main wing mass, tail wing mass and installation position 4 are determined. The size and installation position are determined as shown in the attached figure. Figure 6 As shown;

[0065] The rocket-assisted folding-wing glider enters the sky at a certain launch angle under the thrust of the rocket engine. The wings open immediately after leaving the launch pad. In the entire process from launch to landing, the following assumptions are adopted for the convenience of analysis and calculation:

[0066] 1. Since the glider is small, it can be regarded as a point mass;

[0067] 2. The flight path of the entire glider is a curve in the vertical plane;

[0068] 3. Assume that the air lift, air resistance and thrust of the rocket engine all act on the center of mass of the entire glider;

[0069] 4. During the rocket launch process, although the rocket thrust lasts for a relatively long time, its main effect time is relatively short. In order to simplify the analysis, the average thrust value during the main effect time period is used as the thrust value for theoretical analysis.

[0070] 5. The entire glider flight process is divided into a boost phase 501, a glide phase 502 and a gliding phase 503.

[0071] The glider flight performance verification 5 is the calculation verification work for the three stages of boost phase 501, glide phase 502 and glide phase 503;

[0072] During the boost phase 501, the forces and motions of the glider are as follows: As shown:

[0073] According to Newton's second law, the differential equation of motion of the rocket-assisted glider in the boost stage 501 is obtained:

[0074] (1)

[0075] Where, T is the average thrust of the rocket engine; m is the mass of the glider; , are the velocity components of the glider in the horizontal and vertical directions respectively; t is the time; D is the air resistance of the glider, which are calculated according to the following formulas:

[0076] (2)

[0077] In the formula, , , are the drag coefficient, air density and wing area of ​​the glider respectively.

[0078] According to the initial condition, the velocity is zero, the launch angle and thrust are known, and the acceleration at the initial moment can be calculated according to Formula 1. The thrust action time is divided into n equal parts. As long as n is large enough, each equal time period can be approximately regarded as a uniformly accelerated motion. Therefore, according to the initial conditions, the velocity, displacement and acceleration at the next moment can be calculated. The calculation formula is as follows:

[0079] The angle between the glider's flight direction and the horizontal , can be calculated as follows:

[0080] (3)

[0081] (4)

[0082] (5)

[0083] Wherein dt is the time step. Based on the above formula, the process is realized by MATLAB programming, and finally the boosting stage 501 can be obtained.

[0084] During the gliding phase 502, the glider is subjected to forces and operates as follows: As shown;

[0085] According to Newton's second law, the equation of motion for the coasting phase 502 is:

[0086] (6)

[0087] The solution process is the same as that of the boost phase 501, and its initial conditions are the displacement and velocity at the end of the boost phase 501. The gliding phase 502 is based on the vertical velocity component of the glider during its ascent. Zero is used as the end mark.

[0088] During the gliding phase 503, the glider is subjected to forces and operates as follows: As shown;

[0089] According to Newton's second law, the equation of motion for the gliding phase 503 is:

[0090] (7)

[0091] in, is the air lift, which is calculated as follows:

[0092] (8)

[0093] In the formula, is the lift coefficient.

[0094] The initial conditions are the displacement and velocity at the end of the coasting phase 502. The solution is similar to that of the boosting phase 501 and is not listed here.

[0095] After the previous theoretical analysis, a numerical calculation program was written based on the matlab language platform to simulate the flight process of the model aircraft. The average value of the engine thrust T in this simulation calculation is 5.58N, the engine thrust action time is 3.8s, the air density is 1.205kg / m3, and the air resistance coefficient is , and the air lift coefficient is calculated according to formula 8:

[0096] 21 The glider has a body mass of 157g, a wing area of ​​0.0840 m2, and a launch angle of 85°. The speed and displacement time diagrams, trajectory diagrams, and other attached data of the glider designed in this study are obtained through numerical calculations. Fig.10 , Attachment Fig.11 , Attachment Fig.12 , Attachment Fig.13 and attached Fig.14 .

[0097] Working principle of this embodiment: The basic constituent materials of the rocket-assisted glider include auxiliary ABS injection-molded structural parts, GPI materials, carbon fiber rods, steel wire pull rods, steering gears, batteries, and rubber bands. The flight lift of the glider depends on the design of the wing airfoil. The plano-convex aileron can provide lift for the glider better. Through research on related materials and a large number of experiments, the plano-convex aileron design scheme is finally determined. The lift-to-drag ratio of this type of airfoil is not large, but the stability is relatively good, and it is also relatively easy to make and adjust. It is often used on the wings of catapult models and the tail of competition models. It can also be used on the wings of free aircraft models that require small lift resistance and high-speed climbing. Figure 2It is a cross-section of a flat-convex aileron airfoil; after the wing selection 1 is completed, the main wing size is determined 2, the wing span and the moment of the whole machine are calculated, and then the center of gravity design position is determined 3 to determine that the center of gravity falls at 1 / 3 of the wing width from the leading edge of the wing, and the main wing mass, tail wing mass and installation position 4 are determined at the same time. Finally, the boost stage 501, glide stage 502 and gliding stage 503 calculation of the glider flight performance verification 5 are calculated. Based on the matlab language platform, a numerical calculation program is written to simulate the flight process of the model aircraft. The average value of the engine thrust T in this simulation calculation is 5.58N, the engine thrust action time is 3.8s, the air density is 1.205kg / m3, and the air resistance coefficient is , and the air lift coefficient is calculated according to formula 8:

[0098] (twenty one)

[0099] The fuselage mass of the glider is 157g, the wing area is 0.0840 m2, and the launch angle is 85°. The speed and displacement time diagram, trajectory diagram, etc. of the glider designed in this design are obtained through numerical calculation, as shown in the attached figure; the complete method from the initial wing size to the final product flight verification is a systematic and step-by-step design method, which greatly reduces the design threshold of rocket-propelled gliders. There are formula calculations in each stage of the glider, and the design can be started without physical coordination, which is a good connection between theory and practice. After the theory is reasonable, the components of the physical glider are started, and various modifications when the physical components of the rocket-propelled glider are unreasonable are reduced. The design inspection is carried out through the glider flight performance verification 5, and the virtual inspection of the glider flight is realized, which reduces the number of damages caused by the rocket-propelled glider physical verification flight accidents, reduces the test manufacturing cost and test number of various verification tests of rocket-propelled gliders, and further reduces the flight inspection cost of rocket-propelled gliders, ensuring the consistency of performance of each batch of traditional rocket-propelled gliders.

[0100] In this article, there are a few points to note:

[0101] 1. The drawings of the embodiments of the present disclosure only involve structures related to the embodiments of the present disclosure, and other structures may refer to general designs.

[0102] 2. In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to obtain new embodiments.

[0103] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for designing a rocket-assisted glider, comprising: Wing selection (1), main wing size determination (2), center of gravity design position (3), main wing mass, tail wing mass and installation position (4) and glider flight performance verification (5); characterized in that the wing selection (1) is a flat-convex aileron, the main wing size determination (2) uses the wing span formula: λ=l / b (l-wing span; b-average chord length), the moment is taken at the front end of the nose, and the resultant moment balance formula can be obtained: the moment of the whole machine = the moment of the fuselage + the moment of the main wing + the moment of the tail wing = the weight of the whole machine multiplied by the distance from the center of gravity of the whole machine to the front end of the nose, the center of gravity of the center of gravity design position (3) falls at a position 1 / 3 of the wing width from the leading edge of the wing, and the main wing mass, tail wing mass and installation position (4) are determined while the center of gravity design position (3) is determined.

2. A rocket-assisted glider design method according to claim 1, characterized in that: The moment of the fuselage = the weight of the fuselage multiplied by the distance from the center of gravity of the fuselage to the front end of the nose; the moment of the main wing = the weight of the main wing multiplied by the distance from the center of gravity of the main wing to the front end of the nose; The moment of the tail = the weight of the tail multiplied by the distance from the center of gravity of the tail to the front end of the nose; finally, the design position of the center of gravity of the whole aircraft is determined (3). For a plano-convex wing, according to the above center of gravity adjustment formula, the center of gravity position should be designed to fall at a position 1 / 3 of the wing width from the leading edge of the wing.

3. The method for designing a rocket-assisted glider according to claim 1, characterized in that: The main wing size is determined (2) by the formula Calculate the longitudinal stability. Taking the wing area Aw as the reference plane, the horizontal tail area At should be 0.25 - 0.35Aw at this time to ensure the longitudinal stability of the glider. In the formula is the distance from 1 / 4 of the mean aerodynamic chord length from the trailing edge of the wing to 1 / 4 of the mean aerodynamic chord length from the leading edge of the horizontal tail; Cw is the mean aerodynamic chord length of the wing, obtained by wing area / wingspan; when 0.8 < CTH < 1.25, the longitudinal stability of the glider can be ensured.

4. The method for designing a rocket-assisted glider according to claim 1, characterized in that: The main wing size is determined by (2) formula Calculate the lateral and transverse stability, where Af is the vertical tail area, and its value should be 0.05-0.15 Aw; when 0.15< CTV<0.45, the glider can be guaranteed to have lateral and transverse stability.

5. The method for designing a rocket-assisted glider according to claim 1, characterized in that: The glider flight performance verification (5) includes a boost phase (501), a glide phase (502) and a gliding phase (503). According to Newton's second law, the differential equation of motion of the rocket-assisted glider during the boost phase (501) is obtained: (1) Where, T is the average thrust of the rocket engine; m is the mass of the glider; , are the velocity components of the glider in the horizontal and vertical directions respectively; t is the time; D is the air resistance of the glider, which are calculated according to the following formulas: (2) In the formula, , , are the drag coefficient, air density and wing area of ​​the glider respectively; According to the initial condition, the velocity is zero, the launch angle and thrust are known, and the acceleration at the initial moment can be calculated according to formula (1); the thrust action time is divided into n equal parts. As long as n is large enough, each equal time period can be approximately regarded as a uniformly accelerated motion. Therefore, according to the initial conditions, the velocity, displacement and acceleration at the next moment can be calculated. The calculation formula is as follows: The angle between the glider's flight direction and the horizontal , can be calculated as follows: (3) (4) (5)。 6. A rocket-assisted glider design method according to claim 5, characterized in that: According to Newton's second law, the equation of motion for the gliding phase (502) is: (6) The solution process is the same as that of the boost phase (501). The initial conditions are the displacement and velocity at the end of the boost phase (501). The gliding phase (502) is based on the vertical velocity component of the glider during its ascent. Zero is used as the end mark.

7. A rocket-assisted glider design method according to claim 6, characterized in that: According to Newton's second law, the equation of motion for the gliding phase (503) is: (7) in, is the air lift, which is calculated as follows: (8) In the formula, is the lift coefficient; The initial conditions are the displacement and velocity at the end of the coasting phase (502). The solution is similar to that of the boosting phase (501) and is not listed here.

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