Method for estimating initial mass ratio of two-stage separation type hypersonic aircraft

Abstract

The invention belongs to the field of aerospace, and particularly relates to a method for estimating the initial mass ratio of a two-stage separation type hypersonic aircraft, and the method comprises the steps: preliminarily selecting an energy distribution ratio according to the weight consumption of each stage of aircraft of the two-stage separation type hypersonic aircraft; calculating the initial mass ratio of the two-stage separation type hypersonic aircraft by combining the initial mass ratio of the first-stage aircraft to the second-stage aircraft of the two-stage separation type hypersonic aircraft; and the initial mass ratio of the takeoff weight to the load weight of the two-stage separation type hypersonic aircraft can be quickly calculated. Therefore, design and research and development personnel can better know and master the overall performance of the aircraft, so that optimization design is carried out. Meanwhile, the method is also suitable for estimating the initial mass ratio of the take-off weight to the load weight of other types of hypersonic aircrafts. Through the implementation of the method, the efficiency and accuracy of design, research and development of the hypersonic flight vehicle can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of aerospace, and in particular to a method for estimating the initial mass ratio of a two-stage separation hypersonic aircraft. Background Art

[0002] With the continuous advancement of aerospace technology, two-stage separation hypersonic vehicles, as a means of transport capable of reaching near-space and near-Earth suborbit, are attracting increasing attention. In the design of two-stage separation hypersonic vehicles, the ratio of the vehicle's takeoff weight to its payload weight (hereinafter referred to as the "initial mass ratio") is a critical parameter. A smaller initial mass ratio indicates a higher carrying capacity and lower launch costs, directly impacting the vehicle's performance and payload capacity. The initial mass ratio of a hypersonic vehicle is a key performance metric, directly impacting its payload capacity, launch cost, and safety. Therefore, accurately estimating the initial mass ratio of a two-stage separation hypersonic vehicle is of great significance. Currently, methods for estimating the initial mass ratio of hypersonic vehicles primarily rely on empirical formulas and simulation experiments. In hypersonic vehicle design, the initial mass ratio is a crucial parameter for evaluating vehicle performance. However, existing estimation methods are often complex and require extensive computational and data support, which hinders design work. Therefore, developing a simple and accurate initial mass ratio estimation method is imperative. Summary of the Invention

[0003] The purpose of this application is to provide a method for estimating the initial mass ratio of a two-stage separation hypersonic aircraft to solve the problem that the existing initial mass ratio estimation methods are relatively complex.

[0004] The technical solution of the present application is: a method for estimating the initial mass ratio of a two-stage separation hypersonic aircraft, comprising:

[0005] Conduct force analysis and force equation analysis of a two-stage separation hypersonic vehicle, and simplify the results of force analysis and force equation analysis based on the flight state;

[0006] Determine the efficiency of the integrated design of the first-stage and second-stage aircraft based on the flight-engine integrated design data of the first-stage aircraft's air-breathing powertrain and the fuel type used by the second-stage aircraft's air-breathing powertrain; and determine the effective total efficiency of each stage's air-breathing powertrain based on the performance data of the air-breathing powertrain and the flight-engine integrated design data of each stage.

[0007] The orbital ratio of each stage of the two-stage separation hypersonic aircraft is determined according to the flight design requirements; then, the weight consumption of the first stage and the second stage of the two-stage separation hypersonic aircraft is calculated in combination with the effective total efficiency of the air-breathing power of each stage;

[0008] Calculating the initial mass ratio of the first-stage aircraft and the second-stage aircraft of the two-stage separation hypersonic aircraft according to the empty weight coefficient of the first-stage aircraft and the empty weight coefficient of the second-stage aircraft of the two-stage separation hypersonic aircraft; and combining the weight consumption of the first-stage aircraft and the second-stage separator of the two-stage separation hypersonic aircraft.

[0009] Preliminarily selecting an energy distribution ratio based on the weight consumption of each stage of the two-stage separation hypersonic aircraft; and then calculating the initial mass ratio of the two-stage separation hypersonic aircraft in combination with the initial mass ratio of the first stage and the second stage of the two-stage separation hypersonic aircraft;

[0010] By adjusting different energy distribution ratios and conducting trade-off optimization design, we can obtain the optimal energy distribution ratio, the optimal range of the first-stage aerospace vehicle empty weight coefficient, and the second-stage aerospace vehicle empty weight coefficient for subsequent detailed design analysis.

[0011] Preferably, the force equation of the two-stage separation hypersonic aircraft is:

[0012] m i1 =m p +m e +m f1 +m f2

[0013] m i2 =m p +m e +m f2 =m i -m f1

[0014] m i =m i1

[0015] m i2 =m i2 -m f1

[0016] Π f =Πf 1+ Πf2,

[0017] Where m is the mass of the aircraft, in kg;

[0018] π is the coefficient;

[0019] The subscripts 1 and 2 represent the first-stage carrier and the second-stage carrier, respectively;

[0020] The subscripts i, e, f, and p represent the aircraft's initial takeoff state, empty state, fuel, and load, respectively; Γ represents the initial mass ratio;

[0021] According to the force equation of the two-stage separation hypersonic aircraft, we can obtain:

[0022]

[0023] Where Γ1 is the initial mass ratio of the first-stage vehicle, and Γ2 is the initial mass ratio of the second-stage vehicle.

[0024] Preferably, the fuel type used by the first-stage aircraft air-breathing power and the fuel type used by the second-stage aircraft air-breathing power are hydrocarbon fuel or liquid hydrogen fuel, and the calorific value of the fuel is h PR .

[0025] Preferably, the mass of the first-stage aircraft in an empty state and a loaded state is obtained respectively, and the weight consumption of the first-stage aircraft is calculated as:

[0026]

[0027] Obtain the mass of the second-stage aircraft in the empty state and loaded state respectively, and calculate the weight consumption of the second-stage aircraft as follows:

[0028]

[0029] Where, is the orbit ratio, g0 is the acceleration of gravity on the Earth’s surface, in m / s 2 ; r0 is the average radius of the earth, which is 6371 km; η0 is the total efficiency of the air-breathing power.

[0030] Preferably, the initial mass ratio of the first-stage aircraft and the second-stage aircraft is calculated as follows:

[0031] The empty weight coefficient of the first-stage aircraft is π e1 and the empty weight coefficient Π of the second-stage aircraft e2 Combined with the mass of the aircraft in the empty and loaded states, the initial mass ratio of the first-stage aircraft is obtained as:

[0032]

[0033] The initial mass ratio of the second stage vehicle is:

[0034]

[0035] Substituting into the calculation formula of two-stage weight consumption, we get:

[0036] The initial mass ratio of the first stage vehicle is:

[0037]

[0038] The initial mass ratio of the second stage vehicle is:

[0039]

[0040] Preferably, the method for obtaining the initial mass ratio of the two-stage separation hypersonic vehicle is:

[0041] Let α be the fraction of the total orbital energy provided by the first stage, and 1-α be the fraction of the orbital energy provided by the second stage. Applying the energy distribution to the initial mass ratio of the first and second stages yields:

[0042]

[0043] make The initial mass ratio Γ of a two-stage separated hypersonic vehicle with both stages being air-breathing is calculated as follows:

[0044]

[0045] The present invention's method for estimating the initial mass ratio of a two-stage separation hypersonic aircraft can rapidly calculate the takeoff weight to payload initial mass ratio of a two-stage separation hypersonic aircraft. This helps designers and developers better understand and grasp the overall performance of the aircraft, enabling them to optimize their designs. The method is also applicable to estimating the takeoff weight to payload initial mass ratio of other types of hypersonic aircraft. Implementation of the present invention can effectively improve the efficiency and accuracy of hypersonic aircraft design and development. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0047] Figure 1 This is a schematic diagram of the overall process of this application;

[0048] Figure 2 This is a schematic diagram of the forces acting on the two-stage separation hypersonic aircraft during flight;

[0049] Figure 3 This is a curve diagram of the corresponding relationship between the initial mass ratio and the energy distribution ratio of the two-stage separation hypersonic aircraft of this application. DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] A method for estimating the initial mass ratio of a two-stage separation hypersonic aircraft is proposed. Based on the basic design principles and parameters of a two-stage separation hypersonic aircraft, necessary simplifications and calculations are performed through the mathematical formula of the climb flight phase of the two-stage separation hypersonic aircraft, thereby improving the accuracy and efficiency of the estimation.

[0052] like Figure 1 , including the following steps:

[0053] Step S100 , performing force analysis and force equation analysis on the two-stage separation hypersonic aircraft, and simplifying the force analysis and force equation analysis results in combination with the flight state, such as ignoring the lift and flight path angle during the climbing process.

[0054] A hypersonic vehicle consists of a first-stage vehicle, a second-stage vehicle, and a payload. The first-stage vehicle uses air-breathing power, and the second-stage vehicle also uses air-breathing power. At the separation point of the hypersonic vehicle, the first-stage and second-stage vehicles separate, and the second-stage vehicle continues to transport the payload into near-space or Earth suborbital. Hypersonic vehicles climb at dynamic speeds and altitudes. In this flight state, the speed and geometric altitude of the vehicle will change over time. According to the general force conditions of the vehicle, the following are the Figure 2 As shown (force equation).

[0055] Preferably, the force equation of the two-stage separation hypersonic aircraft is:

[0056] m i1 =m p +m e +m f1 +m f2

[0057] m i2 =m p +m e +m f2 =m i -m f1

[0058] m i =m i1

[0059] m i2 =m i1 -m f1

[0060] Π f =Π f1 +Π f2 ,

[0061] Where m is the mass of the aircraft, in kg;

[0062] π is the coefficient;

[0063] The subscripts 1 and 2 represent the first-stage carrier and the second-stage carrier, respectively;

[0064] The subscripts i, e, f, and p represent the aircraft’s initial takeoff state, empty state, fuel, and load, respectively;

[0065] Γ represents the initial mass ratio.

[0066] According to the force equation of the two-stage separation hypersonic aircraft, we can obtain:

[0067]

[0068] Where Γ1 is the initial mass ratio of the first-stage vehicle, and Γ2 is the initial mass ratio of the second-stage vehicle.

[0069] Step S200: Determine the fuel type used by the first-stage air-breathing power and the second-stage air-breathing power of the two-stage separation hypersonic aircraft, obtain the flight and engine integration design data of the first-stage aircraft and the second-stage aircraft of the current two-stage separation hypersonic aircraft, and determine the efficiency of the integrated design of the first-stage aircraft and the second-stage aircraft respectively. Combined with the performance data of the air-breathing power and the flight-engine integration design data of each stage of the aircraft, the effective total efficiency of the air-breathing power of each stage of the aircraft is determined. η0 is the total efficiency of the aircraft's air-breathing power.

[0070] Preferably, the fuel type used by the first-stage aircraft air-breathing power and the fuel type used by the second-stage aircraft air-breathing power are hydrocarbon fuel or liquid hydrogen fuel, and the fuel calorific value h is determined. PR , unit is J / kg.

[0071] Step S300: Determine the orbit ratio of each stage of the aircraft according to the flight design requirements of the two-stage separation hypersonic aircraft. Then, the weight consumption of the first stage and the second stage separator of the two-stage separation hypersonic vehicle is calculated in combination with the effective total efficiency of the air-breathing power of each stage;

[0072] Preferably, the mass of the first-stage aircraft in an empty state and a loaded state is obtained respectively, and the weight consumption of the first-stage aircraft is calculated as:

[0073]

[0074] Obtain the mass of the second-stage aircraft in the empty state and loaded state respectively, and calculate the weight consumption of the second-stage aircraft as follows:

[0075]

[0076] Where g0 is the acceleration of gravity on the Earth's surface, in m / s 2 ; r0 is the average radius of the earth, which is 6371 km; η0 is the total efficiency of the air-breathing power.

[0077] Step S400: preliminarily select the empty weight coefficient Π of the first stage of the two-stage separation hypersonic aircraft according to the empty weight design requirements of the aircraft. e1 and the empty weight coefficient Π of the second-stage aircraft e2 ; Then, the initial mass ratio of the first-stage aircraft and the second-stage aircraft of the two-stage separation hypersonic aircraft is calculated in combination with the weight consumption of the first-stage aircraft and the second-stage separator of the two-stage separation hypersonic aircraft.

[0078] Preferably, the initial mass ratio of the first-stage aircraft and the second-stage aircraft is calculated as follows:

[0079] The empty weight coefficient of the first-stage aircraft is π e1 and the empty weight coefficient Π of the second-stage aircraft e2 Combined with the mass of the aircraft in the empty and loaded states, the initial mass ratio of the first-stage aircraft is obtained as:

[0080]

[0081] The initial mass ratio of the second stage vehicle is:

[0082]

[0083] Substituting into the calculation formula of two-stage weight consumption, we get:

[0084] The initial mass ratio of the first stage vehicle is:

[0085]

[0086] The initial mass ratio of the second stage vehicle is:

[0087]

[0088] Step S500: Preliminarily select an energy distribution ratio α based on the weight consumption of each stage of the two-stage separation hypersonic aircraft; and then calculate the initial mass ratio of the two-stage separation hypersonic aircraft based on the initial mass ratio of the first stage and the second stage of the two-stage separation hypersonic aircraft.

[0089] Preferably, the method for obtaining the initial mass ratio of the two-stage separation hypersonic vehicle is:

[0090] like Figure 3 , let α be the fraction of the total orbital energy provided by the first stage, and 1-α be the fraction of the orbital energy provided by the second stage, and distribute the energy by the initial mass ratio of the first and second stages to obtain:

[0091]

[0092] make The initial mass ratio Γ of a two-stage separated hypersonic vehicle with both stages being air-breathing is calculated as follows:

[0093]

[0094] Step S600, repeat steps S200-S500, adjust different energy distribution ratios α, perform trade-off optimization design, and obtain the optimal energy distribution ratio α, the first-stage aerospace vehicle empty weight coefficient π e1 、The empty weight coefficient of the second-stage aerospace vehicle Π e2 The optimal intervals of the main influencing parameters are provided for subsequent detailed design analysis.

[0095] The following is a specific example to illustrate: Figure 3 The first stage air-breathing power and the second stage air-breathing power both use liquid hydrogen fuel, and its fuel calorific value h PR =120000kJ / kg, the total effective efficiency of the first-stage air-breathing power and the second-stage air-breathing power is This example Figure 2 It can be seen that when the energy distribution ratio α is 0.5, the initial mass ratio Γ of the two-stage separation hypersonic vehicle can take the minimum value, that is, Λ1=0.7655, Λ2=0.7708, Λ e1 =0.45, ∏ e2 =0.25 Γ min =18.727; Λ1=0.7655, Λ2=0.7708, ∏ e1 =0.40, ∏ e2 =0.20 Γ min=12.657. It can be seen that the minimum value of the initial mass ratio Γ of the two-stage separation hypersonic aircraft has a significant influence on the energy distribution ratio α and the empty weight coefficient Π of the first-stage hypersonic aircraft. e1 、The empty weight coefficient of the second-stage hypersonic vehicle Π e2 Both are very sensitive and require careful weighing and research to obtain and determine the performance and carrying capacity of a relatively excellent two-stage separation hypersonic aircraft.

[0096] In summary, this application can quickly calculate the takeoff weight to payload initial mass ratio of a two-stage separation hypersonic aircraft. This helps designers and developers better understand and grasp the overall performance of the aircraft, allowing for optimized design. Furthermore, this method is also applicable to estimating the takeoff weight to payload initial mass ratio of other types of hypersonic aircraft. Through implementation of this invention, the efficiency and accuracy of hypersonic aircraft design and development can be effectively improved.

[0097] Finally, it should be noted that the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention. Other structures can refer to common designs. In the absence of conflicts, the same embodiment and different embodiments of the present invention can be combined with each other.

[0098] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for estimating the initial mass ratio of a two-stage separation hypersonic vehicle, characterized in that: include: Conduct force analysis and force equation analysis of a two-stage separation hypersonic vehicle, and simplify the results of force analysis and force equation analysis based on the flight state; Determine the efficiency of the integrated design of the first-stage and second-stage aircraft based on the flight-engine integrated design data of the first-stage aircraft's air-breathing powertrain and the fuel type used by the second-stage aircraft's air-breathing powertrain; and determine the effective total efficiency of each stage's air-breathing powertrain based on the performance data of the air-breathing powertrain and the flight-engine integrated design data of each stage. The orbital ratio of each stage of the two-stage separation hypersonic aircraft is determined according to the flight design requirements; then, the weight consumption of the first stage and the second stage of the two-stage separation hypersonic aircraft is calculated in combination with the effective total efficiency of the air-breathing power of each stage; Calculating the initial mass ratio of the first-stage aircraft and the second-stage aircraft of the two-stage separation hypersonic aircraft according to the empty weight coefficient of the first-stage aircraft and the empty weight coefficient of the second-stage aircraft of the two-stage separation hypersonic aircraft; and combining the weight consumption of the first-stage aircraft and the second-stage separator of the two-stage separation hypersonic aircraft. Preliminarily selecting an energy distribution ratio based on the weight consumption of each stage of the two-stage separation hypersonic aircraft; and then calculating the initial mass ratio of the two-stage separation hypersonic aircraft in combination with the initial mass ratio of the first stage and the second stage of the two-stage separation hypersonic aircraft; By adjusting different energy distribution ratios and conducting trade-off optimization design, we can obtain the optimal energy distribution ratio, the optimal range of the first-stage aerospace vehicle empty weight coefficient, and the second-stage aerospace vehicle empty weight coefficient for subsequent detailed design analysis.

2. The method for estimating the initial mass ratio of a two-stage separation hypersonic vehicle according to claim 1, wherein: The force equation of the two-stage separation hypersonic aircraft is: m i1 =m p +m e +m f1 +m f2 m i2 =m p +m e +m f2 =m i -m f1 m i =m i1 m i2 =m i1 -m f1 ∏ f ＝∏ f1 +∏ f2 ， Where m is the mass of the aircraft, in kg; ∏ is the coefficient; The subscripts 1 and 2 represent the first-stage carrier and the second-stage carrier, respectively; The subscripts i, e, f, and p represent the aircraft's initial takeoff state, empty state, fuel, and load, respectively; Γ represents the initial mass ratio; According to the force equation of the two-stage separation hypersonic aircraft, we can obtain: Where Γ1 is the initial mass ratio of the first-stage vehicle, and Γ2 is the initial mass ratio of the second-stage vehicle.

3. The method for estimating the initial mass ratio of a two-stage separation hypersonic vehicle according to claim 2, wherein: The fuel type used by the first-stage aircraft air-breathing power and the fuel type used by the second-stage aircraft air-breathing power are hydrocarbon fuel or liquid hydrogen fuel, and the fuel calorific value is h PR .

4. The method for estimating the initial mass ratio of a two-stage separation hypersonic vehicle according to claim 2, wherein: Obtain the mass of the first-stage aircraft in the empty state and loaded state respectively, and calculate the weight consumption of the first-stage aircraft as follows: Obtain the mass of the second-stage aircraft in the empty state and loaded state respectively, and calculate the weight consumption of the second-stage aircraft as follows: Where, is the orbit ratio, g0 is the acceleration of gravity on the Earth’s surface, in m / s 2 ; r0 is the average radius of the earth, which is 6371 km; η0 is the total efficiency of the air-breathing power.

5. The method for estimating the initial mass ratio of a two-stage separation hypersonic vehicle according to claim 4, wherein: The initial mass ratio of the first-stage vehicle and the second-stage vehicle is calculated as follows: The empty weight coefficient of the first-stage aircraft is π e1 and the empty weight coefficient Π of the second-stage aircraft e2 Combined with the mass of the aircraft in the empty and loaded states, the initial mass ratio of the first-stage aircraft is obtained as: The initial mass ratio of the second stage vehicle is: Substituting into the calculation formula of two-stage weight consumption, we get: The initial mass ratio of the first stage vehicle is: The initial mass ratio of the second stage vehicle is:

6. The method for estimating the initial mass ratio of a two-stage separation hypersonic vehicle according to claim 5, wherein: The method for obtaining the initial mass ratio of the two-stage separation hypersonic aircraft is as follows: Let α be the fraction of the total orbital energy provided by the first stage, and 1-α be the fraction of the orbital energy provided by the second stage. Applying the energy distribution to the initial mass ratio of the first and second stages yields: make The initial mass ratio Γ of a two-stage separated hypersonic vehicle with both stages being air-breathing is calculated as follows:

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