Simulation method of orbit control thermal jet interference effect including temperature influence

Abstract

The invention discloses a simulation method of an orbit control thermal jet disturbance effect containing temperature influence, which comprises the following steps: determining parameters such as incoming flow Mach number, momentum and total enthalpy according to real flight incoming flow conditions, and determining parameters such as real fuel gas jet total pressure, total enthalpy, specific heat ratio and nozzle outlet momentum according to real orbit control engine fuel gas jet parameters; the method comprises the following steps: determining the geometric dimension of a ground research scaling model according to ground research incoming flow conditions under the condition of ensuring that the research appearance is geometrically similar to a spray pipe, simulating the gas of a real orbit control engine by using gas jet flow such as air or gas, and simulating the momentum ratio and the total enthalpy ratio of the jet flow to incoming flow; a ground wind tunnel test or a numerical simulation method is adopted to obtain a force interference factor and an orbit control offset of orbit control thermal jet interference. The method can be used for a thermal spray interference wind tunnel test or numerical simulation.

Description

Technical Field

[0001] The present invention relates to the field of ground simulation of track-controlled thermal jet interference, and in particular to a method for simulating interference force and interference torque of track-controlled thermal jet interference including temperature influence. Background Art

[0002] At present, all major aerospace powers are actively promoting the development of hypersonic offensive and defensive weapons. More and more hypersonic aircraft use jet direct force control technology to adjust flight attitude or improve maneuverability. When the jet engine is working, complex interference flow is generated between the gas jet and the high-speed incoming flow. There are a series of complex flow phenomena in the flow field, such as shock wave / boundary layer interference, shock wave / shock wave interference, flow separation / reattachment, vortex, shear layer, etc., accompanied by jet high temperature, multi-media and secondary combustion effects, which change the aerodynamic / thermal environment of the aircraft as a whole and its components (wings, rudders, etc.) and generate interference forces / torques. Based on different control purposes, jet control technology can be roughly divided into two categories: (1) attitude control jet: the jet nozzle is far away from the center of mass of the aircraft, and the flight attitude is guaranteed or adjusted by providing pitch, yaw and roll torques; (2) trajectory control jet: the jet nozzle is near the center of mass of the missile body, and it provides direct force to achieve high overload and high maneuverability trajectory change. Previously, research on additional interference of attitude control jets usually used normal temperature air jets with similar pressure ratios and momentum ratios to simulate high temperature gas jets, and the simulation results were basically able to meet the needs of engineering applications. In order to enhance maneuverability and penetration capabilities and improve control accuracy, new aircraft to be developed in the future will need to use orbit control jets to provide large overloads to achieve high maneuverability or efficient interception capabilities. Compared with attitude control jets, orbit control jets usually have thrust and flow rates that are more than one order of magnitude larger. The differences in the separation range and pressure distribution of the interference flow fields caused by cold / hot jet interference are significantly increased, and the interference force / torque results obtained from cold jet simulations have large errors, making it difficult to meet the needs of engineering applications. Therefore, a new hot jet simulation strategy needs to be established.

[0003] At present, there is no unified conclusion on the research on the interference effect of orbital control thermal jets. Different studies have selected different similarity parameters, and there is a lack of simulation criteria suitable for orbital control thermal jet simulation. At the same time, compared with the previous pressure ratio and momentum ratio, the similarity parameters do not include temperature effects, which further affects the accuracy. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the deficiencies of the prior art and to provide a method for simulating the orbital control thermal jet interference effect including the influence of temperature.

[0005] The technical solution of the present invention is:

[0006] A simulation method for orbit control thermal jet interference effect including temperature influence, comprising:

[0007] Determine the flow parameters based on the actual flight flow, including Mach number, momentum, and total enthalpy;

[0008] According to the actual orbit control engine gas jet parameters, the actual gas jet total pressure, total enthalpy, specific heat ratio and nozzle exit momentum are determined;

[0009] According to the real aircraft shape, jet nozzle geometry and ground simulation conditions, the geometry of the ground research scale model is determined. The shape and nozzle of the scale model are similar to those of the real aircraft.

[0010] According to the incoming flow conditions simulated on the ground, the ground simulation gas jet is used to simulate the momentum ratio and total enthalpy ratio of the actual orbit control engine jet and the incoming flow, and the simulated jet parameters are determined;

[0011] The force interference factor and orbit control offset caused by orbit control thermal jet interference are obtained by ground wind tunnel tests or numerical simulation methods.

[0012] Preferably, the incoming flow parameters are obtained through the incoming flow conditions and a one-dimensional isentropic relationship.

[0013] Preferably, the total enthalpy of the gas jet is obtained through the gas jet temperature and medium property parameters, and the nozzle outlet momentum is obtained through a one-dimensional isentropic formula.

[0014] Preferably, the incoming flow Mach number and flow pattern of the ground simulation conditions need to be consistent with the actual incoming flow, and the ground research scale model needs to be scaled down according to the ground simulation conditions while satisfying the geometric similarity between the model shape and the jet nozzle size.

[0015] Preferably, the ground simulation jet parameters are determined according to the incoming flow conditions, model size, simulated momentum ratio and total enthalpy ratio of the ground simulation.

[0016] Preferably, the force interference factor K y satisfy

[0017]

[0018] Where, ΔC y is the normal additional disturbance force, C jet is the jet thrust coefficient, C y,jeton ,C y,jetoff It is the aerodynamic coefficient component with and without spray;

[0019] Track control offset

[0020] Where ΔS is the offset distance of the jet thrust action point, L is the length of the projectile, and C mz,jeton , C mz,jetoff It is the pitch direction component of the aerodynamic moment coefficient with and without spray.

[0021] Preferably, a negative value of ΔS represents forward movement, generating a head-down moment; a positive value represents backward movement, generating a head-up moment.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) The present invention provides a method for simulating the orbit control thermal jet interference effect including the influence of temperature, which ensures the momentum ratio and total enthalpy ratio of the jet to the incoming flow, obtains the parameters of the ground simulated jet, and simulates the total enthalpy of the thermal jet while simulating the thermal jet momentum, thereby enabling ground tests or numerical simulations to obtain force interference factors and orbit control offsets. Compared with the traditional cold jet simulation method, the interference force / torque simulation results obtained are closer to the actual flight interference results, thereby improving the simulation accuracy.

[0024] (2) Compared with the original cold spray simulation method, the present invention can further simulate the total pressure ratio and total enthalpy ratio, with more simulation parameters; the jet nozzle and the real hot nozzle meet geometric similarity.

[0025] (3) The simulation method of the present invention is applicable to, but not limited to, air simulation jets;

[0026] (4) The present invention can be used as a supplement to the existing pressure ratio and momentum ratio simulation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of the present invention;

[0028] Figure 2 is a schematic diagram of a typical track-controlled thermal jet nozzle layout provided by an embodiment of the present invention;

[0029] Figure 3 is a schematic diagram of the track-controlled thermal jet interference flow field provided by an embodiment of the present invention;

[0030] Figure 4 It is a result diagram of the orbit control jet force interference factor and the orbit control offset under the simulation strategy provided by the embodiment of the present invention. DETAILED DESCRIPTION

[0031] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to be able to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0032] The present invention establishes a simulation method for the orbit-controlled thermal jet interference flow field including temperature parameters, which provides guidance and basis for ground thermal spray tests or numerical simulation studies of real flight thermal spray interference.

[0033] Figure 1 This is a flow chart of a simulation strategy for the orbital control thermal jet interference effect including temperature influence provided by the present invention. Figure 1 As shown, the method comprises the following steps:

[0034] Step 1: Determine the incoming flow Mach number, momentum, and total enthalpy according to the flight incoming flow conditions. The incoming flow parameters are obtained through the incoming flow conditions and the one-dimensional isentropic relationship.

[0035] Step 2: Determine the actual total pressure, total enthalpy, specific heat ratio, and nozzle exit momentum of the actual gas jet according to the actual orbit control engine gas jet parameters. The jet nozzle exit parameters are obtained according to the one-dimensional isentropic relationship.

[0036] Step 3: According to the ground simulation flow conditions, under the condition that the model shape is similar to the jet nozzle geometry, determine the geometric dimensions of the ground research scale model, simulate the momentum ratio and total enthalpy ratio of the real orbit control engine jet and the incoming flow, and determine the simulated jet parameters.

[0037] Momentum Ratio:

[0038] Total enthalpy ratio:

[0039] Step 4: Use wind tunnel tests or numerical simulation methods to obtain the force interference factor of the orbit control jet interference and the orbit control offset.

[0040] The total enthalpy of the gas jet is obtained through the gas jet temperature and medium property parameters, and the momentum of the nozzle outlet is obtained through a one-dimensional isentropic formula. The ground simulation jet parameters are determined according to the incoming flow conditions, model size, simulated momentum ratio, and total enthalpy ratio of the ground simulation.

[0041] Momentum Ratio:

[0042] Total enthalpy ratio:

[0043] Where: ρ is density, u is velocity, A j is the jet nozzle exit area, A ∞ is the reference area of ​​the incoming flow (the cross-sectional area of ​​the projectile at the nozzle axis position), P is the static pressure, γ is the specific heat ratio, M is the Mach number, c p is the heat capacity at constant pressure, T is the static temperature, the subscript j represents the jet, and the subscript ∞ represents the incoming flow.

[0044] Specifically, is the jet nozzle exit momentum, is the incoming momentum, Pj is the jet static pressure, γ j is the jet specific heat ratio, M j is the jet Mach number, A j is the jet nozzle exit area, P ∞ is the static pressure of the incoming flow, γ ∞ is the specific heat ratio of the incoming flow, M ∞ is the incoming flow Mach number, A ∞ It is the incoming flow reference area.

[0045] h 0j is the total enthalpy of the jet nozzle outlet, h 0∞ is the total enthalpy of the incoming flow, T ∞ is the static temperature of the incoming gas, c pj is the constant pressure heat capacity of the jet nozzle outlet, c p∞ is the constant pressure heat capacity of the flow, T j is the static temperature of the jet gas, u j is the jet nozzle exit velocity, u ∞ It is the incoming flow speed.

[0046] Force interference factor:

[0047] In the formula, K y is the force disturbance factor generated by the jet, ΔC y is the additional interference, C y,jeton ,C y,jetoff is the aerodynamic coefficient component with and without jet (with jet force excluding jet thrust), C jet is the jet thrust coefficient, y represents the normal component, jetoff represents no jet, and jeton represents jet.

[0048] Track control offset:

[0049] Where, ΔS is the offset distance of the jet thrust action point, which means the change in the position of the equivalent jet thrust action point caused by the jet interference. Negative values ​​represent forward movement, resulting in a nose-down moment, and positive values ​​represent backward movement, resulting in a nose-up moment. L is the length of the missile body. ΔS / L% is the percentage of the jet thrust action point offset distance to the total length of the missile body. C mz,jeton ,C mz,jetoff is the aerodynamic torque coefficient component with and without jet (with jet force, the jet torque is not included), C jet is the jet thrust coefficient.

[0050] Example:

[0051] In this embodiment, a typical calculation model is selected as an example for the orbital control jet layout. The calculation model is a typical orbital control jet cone-column-skirt shape. The total length of the model is L = 2250mm, the nozzle outlet diameter is d = 69.8mm, the nozzle axis is located near the center of mass of the projectile, x = 1177mm. The torque reference point is the orbital control jet action point (1177mm, 0, 0). The jet parameters are shown in Table 1, and the incoming flow parameters are shown in Table 2.

[0052] Table 1: Jet parameters

[0053]

[0054] Table 2: Incoming flow parameters

[0055]

[0056] Figure 2 It is a schematic diagram of a typical track-controlled thermal jet nozzle layout provided by an embodiment of the present invention. Figure 3 It is a schematic diagram of the track-controlled thermal jet interference flow field provided by an embodiment of the present invention. Figure 4 This is a result diagram of the orbit control jet force interference factor and orbit control offset under the simulation method provided by the embodiment of the present invention, wherein the force interference factor and orbit control offset obtained by numerical simulation using this simulation strategy are closer to the orbit control hot jet interference result under flight conditions than the cold jet simulation with similar pressure ratio and momentum ratio. The results show that the simulation strategy described in the present invention can significantly improve the numerical simulation accuracy of the orbit control jet force interference factor and orbit control offset compared with the traditional cold jet simulation with similar pressure ratio and momentum ratio.

[0057] The above is an explanation of the preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. For those skilled in the art, various changes or modifications can be obviously imagined within the scope of the claims, which also belong to the technical scope of the present invention.

Claims

1. A method for simulating the interference effect of orbital control thermal jets including temperature influence, characterized in that: include: Determine the flow parameters based on the actual flight flow, including Mach number, momentum, and total enthalpy; According to the actual orbit control engine gas jet parameters, the actual gas jet total pressure, total enthalpy, specific heat ratio and nozzle exit momentum are determined; According to the real aircraft shape, jet nozzle geometry and ground simulation conditions, the geometry of the ground research scale model is determined. The shape and nozzle of the scale model are similar to those of the real aircraft. According to the incoming flow conditions simulated on the ground, the ground simulation gas jet is used to simulate the momentum ratio and total enthalpy ratio of the actual orbit control engine jet and the incoming flow, and the simulated jet parameters are determined; The force interference factor and orbit control offset caused by orbit control thermal jet interference are obtained by ground wind tunnel tests or numerical simulation methods.

2. The method for simulating the orbital control thermal jet interference effect including temperature influence according to claim 1, characterized in that: The incoming flow parameters are obtained through the incoming flow conditions and the one-dimensional isentropic relationship.

3. The method for simulating the orbit control thermal jet interference effect including temperature influence according to claim 1, characterized in that: The total enthalpy of the gas jet is obtained through the gas jet temperature and medium property parameters, and the nozzle outlet momentum is obtained through a one-dimensional isentropic formula.

4. The method for simulating the orbit control thermal jet interference effect including temperature influence according to claim 1, characterized in that: The Mach number and flow pattern of the incoming flow under ground simulation conditions need to be consistent with the actual incoming flow, and the ground research scale model needs to be scaled down according to the ground simulation conditions while satisfying the geometric similarity between the model shape and the jet nozzle size.

5. The method for simulating the orbit control thermal jet interference effect including temperature influence according to claim 1, characterized in that: The ground simulation jet parameters are determined according to the incoming flow conditions, model size, simulated momentum ratio and total enthalpy ratio of the ground simulation.

6. The method for simulating the orbit control thermal jet interference effect including temperature influence according to claim 1, characterized in that: Force interference factor K y satisfy Where, ΔC y is the normal additional disturbance force, C jet is the jet thrust coefficient, C y,jeton ,C y,jetoff It is the aerodynamic coefficient component with and without spray; Track control offset Where ΔS is the offset distance of the jet thrust action point, L is the length of the projectile, and C mz,jeton , C mz,jetoff It is the pitch direction component of the aerodynamic moment coefficient with and without spray.

7. The method for simulating the orbit control thermal jet interference effect including temperature influence according to claim 6, characterized in that: A negative ΔS value represents forward movement, which generates a head-down moment; a positive ΔS value represents backward movement, which generates a head-up moment.

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