Method for determining flight corridor speed-height boundary of aircraft returning to and reentering atmospheric layer
By combining theoretical analysis and analytical methods with boundary parameters, heat flux, dynamic pressure, and overload constraints, the flight corridor boundary for hypersonic vehicles to re-enter the atmosphere is determined, solving the problems of insufficient accuracy and long time consumption in existing technologies, and realizing efficient and accurate vehicle control and optimization.
Patent Information
- Application Number
- CN202511111453.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-08
- Publication Date
- 2025-11-28
AI Technical Summary
Existing technologies for calculating the velocity-altitude boundary of the flight corridor during hypersonic vehicle reentry into the atmosphere are insufficiently accurate, time-consuming, and poorly adaptable, making it difficult to meet the requirements for real-time control and optimization.
Using theoretical analysis and analytical methods, combined with boundary parameters, heat flux, dynamic pressure and overload constraints, the velocity-altitude boundary of the flight corridor is determined by drawing, and an efficient and accurate calculation model for the boundary conditions of the flight corridor for aircraft re-entry into the atmosphere is established.
It improves the accuracy and reliability of the calculation results, shortens the calculation time, enhances the applicability of the method, and can be applied to various types of hypersonic vehicles, meeting the needs of real-time control and optimization, and providing technical support.
Smart Images
Figure CN121031046A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of determining the speed-height boundary of the flight corridor of a reentry vehicle into the atmosphere, and particularly relates to a method for determining the speed-height boundary of the flight corridor of a reentry vehicle into the atmosphere. BACKGROUND
[0002] With the rapid development of aerospace technology, as a new type of vehicle, hypersonic vehicles have shown great application potential in the field of spaceflight. However, when a hypersonic vehicle reenters the atmosphere, due to its extremely high flight speed, usually reaching or exceeding Mach 5, it faces extremely complex physical environments and technical challenges during the reentry process.
[0003] When a hypersonic vehicle reenters the atmosphere in a ballistic manner, it enters the dense atmosphere from the space environment in a very short time. At this time, the surface of the vehicle will generate extremely high temperature due to the violent friction with the atmosphere, and the problem of aerodynamic heating is particularly prominent. It is necessary to strictly control the flight trajectory of the vehicle within a specific flight corridor to avoid excessive overload or excessive heat flux density from damaging the vehicle structure, which puts high requirements on the trajectory optimization and boundary condition calculation of the hypersonic vehicle reentering the atmosphere in a ballistic manner.
[0004] Currently, the method of combining numerical simulation and empirical formula is mainly used to calculate the speed-height boundary of the flight corridor of the vehicle reentering the atmosphere. During the calculation process, a large number of parameter assumptions and simplifications are often relied on, which makes it difficult to meet the engineering practical requirements in terms of the accuracy and reliability of the calculation results. In particular, for hypersonic vehicles reentering the atmosphere in a ballistic manner, due to the stronger dynamics and complexity of the reentry process, the existing calculation methods have obvious deficiencies in real-time performance and adaptability. In addition, although the numerical simulation method can provide more accurate calculation results, its calculation process is complex and time-consuming, making it difficult to achieve rapid iteration and real-time control in actual flight processes. Due to the limited scope of application, the empirical formula is often difficult to apply to different types of vehicles or different flight conditions, which makes the calculation of the speed-height boundary of the flight corridor of the vehicle reentering the atmosphere a key problem that needs to be solved urgently.
[0005] Therefore, how to establish an efficient and accurate method for calculating the speed-height boundary of the flight corridor of the vehicle reentering the atmosphere through theoretical analysis and analytical methods, which can quickly calculate the speed-height boundary of the flight corridor of the vehicle reentering the atmosphere under different flight conditions, has high reliability and adaptability in actual engineering applications, and meets the needs of real-time control and optimization of the vehicle, has become an important topic in the current research on the reentry technology of hypersonic vehicles into the atmosphere. In view of this, the present application is proposed. SUMMARY
[0006] The purpose of the present application is to provide a return reentry atmospheric vehicle flight corridor speed-height boundary determination method to overcome or alleviate at least one aspect of the known technical defects.
[0007] The technical solution of the present application is:
[0008] A return reentry atmospheric vehicle flight corridor speed-height boundary determination method, comprising:
[0009] Step one, calculating the flight corridor speed-height boundary of the return reentry atmospheric vehicle boundary parameter constraint;
[0010] Step two, calculating the flight corridor speed-height boundary of the return reentry atmospheric vehicle heat flow constraint, specifically:
[0011]
[0012] Wherein, h is the flight altitude; H is the atmospheric scale height; is the maximum limit heat flow of the vehicle; K Q is the heat flow rate constant; V is the flight speed; p0 is the reference height atmospheric density;
[0013] Step three, calculating the flight corridor speed-height boundary of the return reentry atmospheric vehicle dynamic pressure constraint, specifically:
[0014]
[0015] Wherein, q max is the maximum limit dynamic pressure of the vehicle;
[0016] Step four, calculating the flight corridor speed-height boundary of the return reentry atmospheric vehicle overload constraint, specifically:
[0017]
[0018] Wherein, N max is the maximum limit overload of the vehicle; W is the vehicle gravity, C D is the vehicle drag coefficient; S is the vehicle reference area;
[0019] Step five, synthesizing the flight corridor speed-height boundary of the boundary parameter, heat flow, dynamic pressure, and overload constraints to obtain the flight corridor speed-height boundary of the return reentry atmospheric vehicle.
[0020] According to at least one embodiment of this application, in the above-described method for determining the velocity-altitude boundary of a reentry vehicle's flight corridor, in step one, the boundary parameters for the vehicle's reentry into the atmosphere include gravitational acceleration g, vehicle track angle γ, reference altitude atmospheric density ρ0, atmospheric-scale altitude H, and vehicle lift parameter W / (C). D S).
[0021] According to at least one embodiment of this application, in the above-described method for determining the velocity-altitude boundary of a flight corridor for a reentry vehicle, step one, calculating the velocity-altitude boundary of the flight corridor constrained by the boundary parameters, specifically involves:
[0022]
[0023] Where V0 is the initial velocity of the aircraft.
[0024] According to at least one embodiment of this application, in the above-described method for determining the velocity-altitude boundary of the flight corridor for a reentry vehicle, in step two, the heat flow rate constant K... Q Take 7.9686×10 -5 Js 2 / (m 3.5 kg 0.5 ).
[0025] According to at least one embodiment of this application, in the above-described method for determining the velocity-altitude boundary of the flight corridor for a reentry vehicle, in step five, a plotting method is used to synthesize the velocity-altitude boundary of the flight corridor based on boundary parameters, heat flux, dynamic pressure, and overload constraints, thereby obtaining the velocity-altitude boundary of the flight corridor for the reentry vehicle.
[0026] This application has at least the following beneficial technical effects:
[0027] This paper presents a method for determining the velocity-altitude boundary of the flight corridor for hypersonic vehicles re-entering the atmosphere. Addressing the shortcomings of existing methods for calculating the boundary conditions of hypersonic vehicle re-entry flight corridors—namely, insufficient accuracy, computational time, and poor adaptability—this method establishes an accurate computational model for the boundary conditions of hypersonic vehicle re-entry flight corridors. This model can meet the real-time control and optimization requirements of the vehicle under various flight conditions. Combining theoretical derivation and numerical verification, this method effectively improves the accuracy and reliability of the calculation results while significantly reducing computation time and enhancing its applicability. It is applicable to various types of hypersonic vehicles and different re-entry flight environments, providing technical support for the safe re-entry of hypersonic vehicles. Attached Figure Description
[0028] Figure 1is a schematic diagram of force of a ballistic return reentry into the atmosphere hypersonic vehicle provided by an embodiment of the present application;
[0029] Figure 2 is a schematic diagram of a method for determining a speed-height boundary of a flight corridor of a return reentry into the atmosphere vehicle provided by an embodiment of the present application;
[0030] Figure 3 is a schematic diagram of a speed-height boundary of a flight corridor of a return reentry into the atmosphere vehicle provided by an embodiment of the present application, which comprehensively considers boundary parameters, heat flow, dynamic pressure, and overload constraints.
[0031] In order to better illustrate the embodiments, some contents in the drawings may be omitted, enlarged or reduced, and are only used for exemplary illustration, and cannot be understood as a limitation on the present application. DETAILED DESCRIPTION
[0032] In order to make the technical solutions of the present application and the advantages thereof clearer, the technical solutions of the present application will be further clearly, completely and specifically described below with reference to the drawings. It should be understood that the specific embodiments described herein are only some embodiments of the present application, which are used to explain the present application, but not to limit the present application. It should be noted that, for the convenience of description, only parts related to the present application are shown in the drawings, and other related parts can be referred to the general design.
[0033] In addition, unless otherwise defined, the technical terms or scientific terms used in the present application description should be the general meanings understood by the general technical personnel in the field of the present application. The "comprise" used in the present application description indicates that the concept appearing before the word covers the concepts listed after the word and its equivalents, and does not exclude other associated concepts.
[0034] The force of the ballistic return reentry into the atmosphere hypersonic vehicle is as shown in Figure 1 The dynamics equation along the flight path is:
[0035]
[0036] Wherein, W is the weight of the vehicle; γ is the flight path angle of the vehicle, that is, the angle between the flight path and the horizontal plane; D is the resistance of the vehicle; m is the mass of the vehicle; V is the flight speed; t is the flight time.
[0037] Under the small angle approximation (sin γ ≈ 0), it can be simplified as:
[0038]
[0039] Wherein, g is the acceleration of gravity.
[0040] Substituting The following can be obtained:
[0041]
[0042] where ρ is the atmospheric density; C D is the aerodynamic drag coefficient; S is the reference area of the aircraft.
[0043] Further rearrangement gives:
[0044]
[0045] where, The overall is the ballistic parameter.
[0046] The atmospheric density ρ is calculated as:
[0047] ρ = ρ0exp(-h / H);
[0048] where ρ0 is the atmospheric density at the reference height; H is the atmospheric scale height; h is the flight altitude.
[0049] h = R - R r , where R is the radius of curvature of the flight path; R r is the average radius of the Earth.
[0050] The rate of change of flight altitude is calculated as:
[0051]
[0052] Then can be further expressed as:
[0053]
[0054]
[0055] There is:
[0056] is a separable variable differential equation, which can be rearranged by separating variables to obtain:
[0057] Integrating both sides gives:
[0058]
[0059]
[0060] Integrating gives:
[0061]
[0062]
[0063] Further, there is:
[0064]
[0065] Where V0 = exp(C), is the initial velocity of the aircraft.
[0066] Constraints for an aircraft's reentry into the atmosphere include thermal flow constraints, dynamic pressure constraints, and overload constraints.
[0067] The heat flux of the aircraft is calculated as follows:
[0068]
[0069] in, For aircraft heat flow; K Q Let be the heat flow rate constant, taken as 7.9686 × 10⁻⁶. -5 Js 2 / (m 3.5 kg 0.5 ); To limit the heat flow of the aircraft to the maximum extent.
[0070] Let ρ = ρ0e -h / H Substituting, we get:
[0071]
[0072] Furthermore:
[0073] in, The altitude is the limit for the maximum heat flux of the aircraft.
[0074] The dynamic pressure of the aircraft is calculated as follows:
[0075]
[0076] Where q is the dynamic pressure of the aircraft; q max This is the maximum limiting dynamic pressure for the aircraft.
[0077] Let ρ = ρ0e -h / H Substituting, we get:
[0078] Among them, hq max The maximum dynamic pressure limit altitude for an aircraft.
[0079] Aircraft overload calculations are based on aerodynamic lift, aerodynamic drag, and aircraft weight, as detailed below:
[0080]
[0081] Where, N l For aircraft overload; L is aircraft lift; N maxThe maximum limit overload of the aircraft.
[0082] The aircraft lift L and drag D are calculated as follows:
[0083]
[0084]
[0085] wherein C L is the lift coefficient of the aircraft.
[0086] Further, there are:
[0087]
[0088] Substitute ρ = ρ0e -h / H into the above equation, we have:
[0089]
[0090] Further, there are:
[0091]
[0092]
[0093] wherein, is the maximum overload limit height of the aircraft.
[0094] The aircraft is a ballistic reentry into the atmosphere, C L ≈ 0, further there are:
[0095]
[0096]
[0097] Based on the above, the application provides a method for determining the speed-height boundary of the flight corridor of the reentry aircraft into the atmosphere, as shown in Figure 2 .
[0098] Step one, calculate the speed-height boundary of the flight corridor of the reentry aircraft into the atmosphere, constrained by boundary parameters.
[0099] The boundary parameters of the reentry aircraft into the atmosphere include gravitational acceleration g, flight path angle γ, reference height atmospheric density ρ0, atmospheric scale height H, and aircraft lift parameter W / (C D S), wherein W is the weight of the aircraft, C D is the drag coefficient of the aircraft; and S is the reference area of the aircraft.
[0100] The speed-height boundary of the flight corridor constrained by the boundary parameters is calculated, specifically:
[0101]
[0102] wherein, V is the flight speed; h is the flight altitude; V0 is the initial speed of the aircraft, which can be calculated from the initial conditions by .
[0103] Step two, calculating the speed-altitude boundary of the flight corridor of the aircraft returning to re-enter the atmosphere with heat flow constraints, specifically:
[0104]
[0105] wherein, is the maximum limit heat flow of the aircraft; K Q is the heat flow rate constant, taking 7.9686 x 10 -5 Js 2 / (m 3.5 kg 0.5 ).
[0106] Step three, calculating the speed-altitude boundary of the flight corridor of the aircraft returning to re-enter the atmosphere with dynamic pressure constraints, specifically:
[0107]
[0108] wherein, q max is the maximum limit dynamic pressure of the aircraft.
[0109] Step four, calculating the speed-altitude boundary of the flight corridor of the aircraft returning to re-enter the atmosphere with overload constraints, specifically:
[0110]
[0111] wherein, N max is the maximum limit overload of the aircraft.
[0112] Step five, synthesizing the speed-altitude boundary of the flight corridor with boundary parameters, heat flow, dynamic pressure, and overload constraints, obtaining the speed-altitude boundary of the flight corridor of the aircraft returning to re-enter the atmosphere, which can be obtained through the way of drawing.
[0113] In a specific example, the gravitational acceleration g = 9.81 m / s 2 , the ballistic parameter W / (C D S) = 448 N / ㎡, the aircraft track angle γ = -1°, the reference altitude atmospheric density ρ0 = 1.225 kg / m 2 , the atmospheric scale height H = 8500 m, and the constant aircraft initial speed V0 = 11.2 km / s is calculated according to the initial conditions of the ballistic returning re-entry into the atmosphere of the hypersonic aircraft.
[0114] The return reentry into the atmosphere vehicle flight corridor speed-height boundary determination method disclosed in the above embodiment is implemented as follows:
[0115] Step one: set two groups of boundary parameters:
[0116] The first group: gravitational acceleration g = 9.81 m / s 2 , ballistic parameters Vehicle flight path angle γ = -1°, reference height atmospheric density ρ0 = 1.225 kg / m2, atmospheric scale height H = 8500 m;
[0117] The second group: gravitational acceleration g = 9.81 m / s 2 , ballistic parameters Vehicle flight path angle γ = -1°, reference height atmospheric density ρ0 = 1.225 kg / m2, atmospheric scale height H = 8500 m.
[0118] Calculate the flight corridor speed-height boundary constrained by the boundary parameters:
[0119] Step two, maximum limit heat flow of the vehicle Take 400 kW / m2, heat flow rate constant K Q Take 7.9686 × 10 - 5 Js 2 / (m 3.5 kg 0.5 ), calculate the flight corridor speed-height boundary constrained by the heat flow:
[0120] Step three, maximum limit dynamic pressure q of the vehicle max Take 40 kPa, calculate the flight corridor speed-height boundary constrained by the dynamic pressure:
[0121] Step four, maximum limit overload N of the vehicle max Take 4, calculate the flight corridor speed-height boundary constrained by the overload:
[0122] Step five, the flight corridor speed-height boundary constrained by the boundary parameters, heat flow, dynamic pressure, and overload is integrated, the speed-height boundary graph is drawn, and the return reentry into the atmosphere flight corridor speed-height boundary of the vehicle is obtained, as shown in Figure 3 .
[0123] The return reentry into the atmosphere vehicle flight corridor speed-height boundary determination method disclosed in the above embodiments is used for calculating and determining the flight corridor boundary of a hypersonic vehicle reentering the atmosphere. Through theoretical analysis and numerical verification, the method can significantly improve the calculation accuracy and reliability, greatly shorten the calculation time, and has strong real-time and adaptability. Compared with the existing numerical simulation and empirical formula method, the flight corridor boundary under different flight conditions can be determined more quickly and accurately, meeting the needs of real-time control and optimization of the vehicle. The efficiency and adaptability of the method make it suitable for various types of hypersonic vehicles and different return reentry into the atmosphere flight environments, providing a solid and reliable technical guarantee for the safe return reentry into the atmosphere of hypersonic vehicles, and promoting the practical application and development of hypersonic vehicles in the field of aerospace.
[0124] So far, the technical solution of the present application has been described in combination with the preferred embodiments shown in the drawings, and those skilled in the art should understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without deviating from the principles of the present application, those skilled in the art can make equivalent changes or replacements to related technical features, and the technical solutions after these changes or replacements will fall within the protection scope of the present application.
Claims
1. A method for determining the velocity-altitude boundary of a flight corridor for a reentry vehicle, characterized in that, include: Step 1: Calculate the velocity-altitude boundary of the flight corridor for the aircraft's reentry into the atmosphere, constrained by boundary parameters; Step 2: Calculate the velocity-altitude boundary of the flight corridor under thermal flow constraints for the spacecraft's reentry into the atmosphere. Specifically: Where h is the flight altitude; H is the atmospheric altitude; To limit the heat flux of the aircraft; K Q ρ is the heat flow rate constant; V is the flight speed; ρ0 is the atmospheric density at the reference altitude; Step 3: Calculate the velocity-altitude boundary of the flight corridor under dynamic pressure constraints for the spacecraft's reentry into the atmosphere. Specifically: Where, q max The maximum limiting dynamic pressure for the aircraft; Step 4: Calculate the velocity-altitude boundary of the flight corridor under overload constraints for the spacecraft's reentry into the atmosphere. Specifically: Where, N max W represents the maximum overload limit of the aircraft; C represents the aircraft's gravity. D S is the drag coefficient of the aircraft; S is the reference area of the aircraft. Step 5: By integrating boundary parameters, heat flux, dynamic pressure, and overload constraints, the velocity-altitude boundary of the flight corridor is obtained, thus determining the velocity-altitude boundary of the spacecraft's reentry flight corridor.
2. The method for determining the velocity-altitude boundary of the flight corridor for a reentry vehicle according to claim 1, characterized in that, In step one, the spacecraft re-enters the atmosphere. Boundary parameters include gravitational acceleration g, spacecraft track angle γ, reference altitude atmospheric density ρ0, atmospheric-scale altitude H, and spacecraft lift parameter W / (C). D S).
3. The method for determining the velocity-altitude boundary of the flight corridor for a reentry vehicle according to claim 2, characterized in that, In step one, the flight corridor velocity-altitude boundary parameters are calculated, specifically as follows: Where V0 is the initial velocity of the aircraft.
4. The method for determining the velocity-altitude boundary of the flight corridor for a reentry vehicle according to claim 3, characterized in that, In step two, the heat flow rate constant K Q Take 7.9686×10 -5 Js 2 / (m 3.5 kg 0.5 ).
5. The method for determining the velocity-altitude boundary of the flight corridor for a reentry vehicle according to claim 4, characterized in that, In step five, a plotting method is used to synthesize the velocity-altitude boundary of the flight corridor based on boundary parameters, heat flux, dynamic pressure, and overload constraints, thus obtaining the velocity-altitude boundary of the spacecraft's reentry flight corridor.