Fuel gas flow guide device and parameter design method thereof

Abstract

The invention provides a fuel gas flow guiding device and a parameter design method thereof, and belongs to the field of liquid rocket engine high-altitude simulation. One end of a second flow guiding plate of the fuel gas flow guiding device is fixedly connected with one end of a first flow guiding plate, and the first flow guiding plate and the second flow guiding plate have an opening angle; the center line of the opening angle coincides with the center line of the fuel gas inlet of the gas collecting chamber, and the opening angle is opposite to the fuel gas outlets of the gas collecting chamber. The third guide plate is connected with the other end of the first guide plate and is parallel to the axis of the gas collection chamber; the fourth guide plate is connected with the other end of the second guide plate and is parallel to the axis of the gas collection chamber; and the lower ends of the first guide plate, the second guide plate, the third guide plate and the fourth guide plate are fixedly connected with the inner wall of the gas collection chamber. Through the flow guide device parameter design method, the structural design key parameters of the flow guide device can be optimized, so that the fuel gas enters a plurality of groups of indirect coolers which are connected in parallel after being uniformly distributed as far as possible.

Description

Technical Field

[0001] This invention belongs to the field of high-altitude simulation of liquid rocket engines, and specifically relates to a gas flow guiding device and its parameter design method. Background Technology

[0002] During high-altitude simulation tests of liquid rocket engines, a large amount of high-temperature, high-speed, and corrosive combustion gases are generated. These gases are decelerated and pressurized by a diffuser before being cooled by a spray cooler and an indirect cooler, and finally pumped into the atmosphere by a jet pump. However, for liquid rocket engines with a thrust of 10 kN or more, the gas flow rate and enthalpy are large. If the gas is cooled by a spray cooler and then by a single indirect cooler, the size, weight, manufacturing, transportation, installation, use, and maintenance costs of the indirect cooler will increase dramatically, making it difficult to meet actual engineering requirements. To achieve high-altitude simulation tests of high-thrust liquid rocket engines, multiple sets of indirect coolers, either in series or in parallel, can be used to cool the combustion gases. For series-connected indirect coolers, the heat load is concentrated on the upstream cooler, leading to a sharp decrease in the reliability of the upstream cooler during use. Therefore, high-altitude simulation test benches for liquid rocket engines generally adopt a structure with multiple sets of indirect coolers in parallel to cool the large flow rate and high enthalpy combustion gases.

[0003] However, when using multiple sets of indirect coolers in parallel to cool the gas, the uneven distribution of the gas entering the multiple sets of indirect coolers leads to an unbalanced load on the multiple coolers, which in turn reduces the cooling effect and affects the heat exchange efficiency of the coolers. Summary of the Invention

[0004] To overcome the shortcomings of the existing technology, the present invention provides a gas diversion device located in the gas collection chamber of a liquid rocket engine. The gas collection chamber is a hollow cylinder with a gas inlet on one side and multiple gas outlets symmetrically arranged on the other side. Each gas outlet is connected to a set of indirect coolers. The gas diversion device includes: First deflector plate; The second guide plate is fixedly connected at one end to the first guide plate. The joint between the first guide plate and the second guide plate is arranged at a preset opening angle. The center line of the opening angle coincides with the center line of the gas inlet of the gas collecting chamber. The opening of the opening angle faces the gas outlet. The third and fourth guide plates are respectively set on both sides of the opening angle, and are both set parallel to the axis of the gas collection chamber. The third guide plate is connected to the other end of the first guide plate, and the fourth guide plate is connected to the other end of the second guide plate. The lower ends of the first guide plate, the second guide plate, the third guide plate and the fourth guide plate are all fixedly connected to the inner wall of the gas collection chamber.

[0005] Preferably, the gas flow guiding device further includes a cooling structure, which includes: The enclosed assembly, together with the first guide plate, the second guide plate, the third guide plate, and the fourth guide plate, constitutes a cooling water tank; The reinforcement component is located outside the cooling water tank and is fixedly connected to the enclosure component. A water supply pipe is located at the lower end of the enclosed assembly and is connected to the enclosed assembly. Two drain pipes are located at the upper end of the enclosure and are connected to the enclosure.

[0006] Preferably, the enclosure component includes: Two cone plates are arranged parallel to the first guide plate and the second guide plate, respectively, and the two cone plates are fixedly connected at their closest ends; Two flat plates are arranged parallel to the third and fourth guide plates, respectively; one end of each flat plate is fixedly connected to the end of the two cone plates furthest away from each other. The upper base plate is connected to the upper ends of two conical plates and two flat plates on one side; both drainage pipes are connected to the upper base plate. The bottom plate is connected to the upper ends of two conical plates and two flat plates on one side, and is fixedly connected to the inner wall of the gas collection chamber on the other side; the water supply pipe is connected to the bottom plate. The top plate is fixedly connected to the first guide plate, the second guide plate, the third guide plate and the fourth guide plate on one side, and fixedly connected to the other side of the bottom plate on the other side, and there is a gap between the top plate and the air collection chamber. The first side sealing plate and the second side sealing plate are respectively disposed outside the third guide plate and the fourth guide plate. The upper end of the first side sealing plate is connected to the upper top plate, the lower end is connected to the inner wall of the gas collecting chamber, and the two sides are respectively connected to the third guide plate and a flat plate. The upper end of the second side sealing plate is connected to the upper top plate, the lower end is connected to the inner wall of the gas collecting chamber, and the two sides are respectively connected to the fourth guide plate and another flat plate.

[0007] Preferably, the reinforcement component includes: Two first stiffening plates are arranged vertically at intervals on one side of the opening angle, and each side is connected to two flat plates; Two second stiffeners are spaced apart in the horizontal direction and are perpendicular to the first stiffener located above them. One end of each of the two second stiffeners is connected to two flat plates. Two third stiffeners are spaced apart horizontally and perpendicularly penetrate the first stiffener located below them. One end of each third stiffener is connected to two flat plates.

[0008] Preferably, the gas inlet is connected to the diffuser.

[0009] Preferably, the gas collection chamber is made of Q345r high-temperature resistant carbon steel, the flow guiding device is made of S321 high-temperature resistant stainless steel, and a high-temperature resistant and erosion-resistant coating is sprayed on the windward side of the flow guiding device.

[0010] This invention also provides a parameter design method for a gas flow guiding device, comprising the following steps: Obtain key structural design parameters for the gas collection chamber and flow guiding device, and construct a three-dimensional initial model of the gas collection chamber and flow guiding device; The gas flow rate at the gas inlet of the gas collecting chamber in the three-dimensional initial model is set as the first boundary condition, and the gas pressure and velocity gradient at the gas outlet are set as the second boundary condition. The three-dimensional initial model is meshed, and the gas flow field continuity equation and momentum equation are used to simulate the gas flow process of the meshed three-dimensional initial model. The gas flow field continuity equation and momentum equation are solved, and the gas flow distribution non-uniformity and gas pressure loss are judged based on the solution results. If not, the key parameters of the flow guiding device are updated, and the boundary condition setting process and flow guiding simulation process are repeated until the gas flow distribution non-uniformity and gas pressure loss reach the set threshold, and the final key parameters of the structural design are obtained.

[0011] Preferably, the key structural design parameters include the opening angle of the first guide plate and the second guide plate, the distance between the unconnected ends of the first guide plate and the second guide plate, the distance between the third guide plate and the fourth guide plate and the axis of the gas collection chamber, and the distance between two adjacent gas outlets.

[0012] Preferably, the formula for calculating the first boundary condition is as follows: ; Where, This refers to the total flow rate of the gas after being cooled by the spray water. This refers to the gas flow rate during the operation of a liquid rocket engine. This refers to the flow rate of the spray cooling water.

[0013] Preferably, the second boundary condition is as follows: ; ; ; ; Where, u , v , w and p These represent the gas velocity component and pressure within the gas flow domain. x , y and zFor different directions.

[0014] The gas flow guiding device and its parameter design method provided by this invention have the following beneficial effects: This invention achieves a symmetrical structure by designing the first and second guide plates with a certain opening angle, aligning the centerline of the opening angle with the centerline of the gas inlet in the gas collecting chamber. By connecting a third and fourth guide plate to the other ends of the first and second guide plates respectively, the incoming gas is guided to both sides, facilitating uniform gas distribution. Furthermore, by incorporating a flow guiding device between the diffuser and the parallel indirect coolers, this invention ensures the gas is distributed as evenly as possible before entering multiple sets of indirect coolers, thereby improving the heat exchange efficiency of the coolers.

[0015] This invention constructs a three-dimensional initial model of the gas collection chamber and the flow guiding device, sets boundary conditions, and uses the gas flow field continuity equation and momentum equation to simulate the gas flow process of the meshed three-dimensional initial model. This allows for a clearer understanding of the flow direction and distribution of gas in the flow guiding device. By solving the gas flow field continuity equation and momentum equation, it is possible to determine whether the flow guiding device has reached the set thresholds for flow distribution non-uniformity and gas pressure loss under the current key structural design parameters. Based on the judgment results, the key structural design parameters of the flow guiding device are continuously updated until a flow guiding device that meets the indicators of fuel distribution uniformity and gas pressure loss is designed is produced. This allows the gas to enter multiple sets of indirect coolers evenly, improving the heat exchange efficiency of the coolers. Attached Figure Description

[0016] To more clearly illustrate the embodiments and design schemes of the present invention, the accompanying drawings required for this embodiment will be briefly described below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a structural diagram of the gas flow guiding device according to an embodiment of the present invention; Figure 2 This is a longitudinal cross-sectional view of the gas diversion device; Figure 3 This is a cross-sectional view of the gas diversion device; Figure 4 Schematic diagram of cooling water supply principle for the flow guiding device; Figure 5 Schematic diagram of key parameters for the structural design of the flow guiding device; Figure 6 This is a simulation computation domain diagram in an embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1-First guide plate, 2-Second guide plate, 3-Gas collection chamber, 4-Third guide plate, 5-Fourth guide plate, 6-Water supply pipe, 7-Drainage pipe, 8-Conical plate, 9-Flat plate, 10-Upper bottom plate, 11-Lower bottom plate, 12-Upper top plate, 13-First side sealing plate, 14-Second side sealing plate, 15-First stiffening plate, 16-Second stiffening plate, 17-Third stiffening plate, 18-Gas inlet, 19-Gas outlet. Detailed Implementation

[0019] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the technical solution of this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of this invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "connected" or "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. In the description of this invention, unless otherwise stated, "a plurality of" means two or more, which will not be elaborated further here.

[0022] Example: This invention provides a gas diversion device located within the gas collection chamber 3 of a liquid rocket engine, coinciding with the axis of symmetry of the gas collection chamber 3. The gas collection chamber 3 is a hollow cylinder. A gas inlet 18 is provided on one side of the gas collection chamber 3, and multiple gas outlets 19 are symmetrically arranged on the other side. Each gas outlet 19 is connected to a set of indirect coolers. The specific structure of the gas diversion device is as follows: Figures 1-3As shown, the system includes a first guide plate 1, a second guide plate 2, a third guide plate 4, and a fourth guide plate 5. One end of the second guide plate 2 is fixedly connected to one end of the first guide plate 1. The joint between the first guide plate 1 and the second guide plate 2 is arranged at a preset opening angle, and the center line of the opening angle coincides with the center line of the gas inlet 18 of the gas collecting chamber 3. The opening of the opening angle faces the gas outlet 19. The third guide plate 4 and the fourth guide plate 5 are respectively arranged on both sides of the opening angle, both parallel to the axis of the gas collecting chamber 3. The third guide plate 4 is connected to the other end of the first guide plate 1, and the fourth guide plate 5 is connected to the other end of the second guide plate 2. The lower ends of the first guide plate 1, the second guide plate 2, the third guide plate 4, and the fourth guide plate 5 are all fixedly connected to the inner wall of the gas collecting chamber 3.

[0023] Furthermore, the gas inlet 18 of this invention is connected to the diffuser. This invention provides a gas collection chamber 3 between the diffuser outlet and multiple sets of parallel indirect coolers. A gas guiding device is installed within the gas collection chamber 3. The various guide plates of the guiding device work together to distribute the gas, ensuring that the gas is distributed as evenly as possible to the parallel indirect coolers. Specifically, through the rational design of the parameters of the first guide plate 1, the second guide plate 2, the third guide plate 4, and the fourth guide plate 5, the gas can be evenly distributed, ensuring that the gas enters the multiple sets of parallel indirect coolers after being distributed as evenly as possible.

[0024] In this embodiment, the gas collecting chamber 3 is made of Q345r high-temperature resistant carbon steel, and the flow guiding device is made of S321 high-temperature resistant stainless steel.

[0025] In this embodiment, the flow guiding device also includes a cooling structure located on one side of the opening angle, comprising a sealing component, a reinforcing component, a water supply pipe 6, and two drain pipes 7. The sealing component, together with the first guide plate 1, the second guide plate 2, the third guide plate 4, and the fourth guide plate 5, forms a cooling water tank; the reinforcing component is located outside the cooling water tank and is fixedly connected to the sealing component; the water supply pipe 6 is located at the lower end of the sealing component and communicates with it; the two drain pipes 7 are located at the upper end of the sealing component and communicate with it. Specifically, the sealing component includes two conical plates 8, two flat plates 9, an upper bottom plate 10, a lower bottom plate 11, an upper top plate 12, a first side sealing plate 13, and a second side sealing plate 14. Two conical plates 8 are respectively arranged parallel to the first guide plate 1 and the second guide plate 2, and the ends of the two conical plates 8 that are close to each other are fixedly connected; two flat plates 9 are respectively arranged parallel to the third guide plate 4 and the fourth guide plate 5; one end of each of the two flat plates 9 is fixedly connected to the ends of the two conical plates 8 that are far away from each other; one side of the upper bottom plate 10 is connected to the upper ends of the two conical plates 8 and the two flat plates 9; two drain pipes 7 are connected to the upper bottom plate 10; one side of the lower bottom plate 11 is connected to the upper ends of the two conical plates 8 and the two flat plates 9, and the other side is connected to the inner wall of the air collection chamber 3; a water supply pipe 6 is connected to the lower bottom plate 11; the upper top plate 12... One side is fixedly connected to the first guide plate 1, the second guide plate 2, the third guide plate 4 and the fourth guide plate 5, and the other side is fixedly connected to the other side of the upper bottom plate 10; the first side sealing plate 13 and the second side sealing plate 14 are respectively set on the outside of the third guide plate 4 and the fourth guide plate 5. The upper end of the first side sealing plate 13 is connected to the upper top plate 12, the lower end is connected to the inner wall of the air collection chamber 3, and the two sides are respectively connected to the third guide plate 4 and a flat plate 9; the upper end of the second side sealing plate 14 is connected to the upper top plate 12, the lower end is connected to the inner wall of the air collection chamber 3, and the two sides are respectively connected to the fourth guide plate 5 and another flat plate 9. The reinforcing assembly includes two first stiffeners 15, two second stiffeners 16, and two third stiffeners 17. The two first stiffeners 15 are vertically spaced on one side of the opening angle, and each is connected to one side of the two flat plates 9. The two second stiffeners 16 are horizontally spaced and perpendicularly penetrate the upper first stiffener 15, and one end of each second stiffener 16 is connected to the two flat plates 9. The two third stiffeners 17 are horizontally spaced and perpendicularly penetrate the lower first stiffener 15, and one end of each third stiffener 17 is connected to the two flat plates 9.

[0026] The cooling structure of this invention can perform preliminary cooling of the gas after it has been cooled by the spray cooler. The heat exchange of the cooling structure mainly includes convective heat transfer and radiative heat transfer. The convective heat flux density q1 between the high-temperature gas and the cooling structure is given by the following formula: ; Where, T is the convective heat transfer coefficient between the high-temperature gas and the flow guiding device. k T represents the gas temperature. bgThis refers to the temperature of the gas-side wall surface of the flow guiding device.

[0027] The radiative heat flux density q2 is given by the following formula: ; Where, The radiative heat flux density generated by CO2 in the fuel gas. It represents the radiative heat flux density generated by H2O (gas) in the fuel gas.

[0028] The total average heat flux density q is the sum of the convective heat flux density q1 and the radiative heat flux density q2, and is given by the following equation: ; Required cooling water flow rate It is given by the following formula: ; In the formula, A is the outer wall area of ​​the flow guiding device, and C p Where L is the specific heat capacity of the cooling water at constant pressure, L is the length of the cooling water flow channel of the guide device, and v is the flow velocity in the cooling water flow channel.

[0029] The schematic diagram of the cooling water supply system for the gas collection chamber 3 and the flow guiding device is shown below. Figure 4 As shown, the cooling water flow rate and pre-spray pressure are directly measured using an electromagnetic flowmeter, avoiding test termination due to measurement system malfunctions. Based on the cooling water outlet temperature measurement results, the required cooling water flow rate for the cooling structure is dynamically and precisely adjusted using a combination of a flow regulating valve and an orifice plate. Specifically, the cooling water flow rate is initially adjusted using the flow regulating valve, and then the accurate cooling water flow rate is obtained by adjusting the orifice plate diameter. The relationship between cooling water flow rate and orifice plate diameter is shown. It is given by the following formula: ; In the formula, C is the orifice plate flow coefficient, which is generally taken as 0.7~1.0; d is the diameter of the cooling water orifice plate; ΔP is the pressure difference before and after the cooling water orifice plate; and ρ is the density of the cooling water.

[0030] This invention also provides a parameter design method based on a gas flow guiding device. According to the construction requirements of a high-altitude simulation test rig for liquid rocket engines, the parameter design of the gas flow guiding device needs to meet the relevant design indicators of the gas collecting chamber 3 and the guiding device under rated operating conditions, such as gas distribution unevenness and gas flow loss. Key structural design parameters affecting the flow distribution unevenness and pressure loss of the guiding device are as follows: Figure 5As shown, the dimensions include the expansion angle θ of the guide cone (the opening angle between the first guide plate 1 and the second guide plate 2), the width L1 of the guide cone 8 (the distance between the unconnected ends of the first guide plate 1 and the second guide plate 2), the width L2 of the guide cone tail plate (the distance between the furthest ends of the third guide plate 4 and the fourth guide plate 5), the relative distance S1 between the tail plate and the internal axis of the gas collecting chamber 3 (the distance between the axis of the third guide plate 4 and the fourth guide plate 5 and the axis of the gas collecting chamber 3), and the relative distance S2 between the axes of the gas outlets 19 (the distance between two adjacent gas outlets 19). After the gas flows through the guide device, it should meet the following requirements: the gas flow distribution non-uniformity should not exceed η, and the gas pressure loss should not exceed [a certain value]. Technical indicators should satisfy the following relationship:

[0031] However, due to the highly complex flow state of the gas near the flow guide device in the gas collecting chamber 3, it is currently impossible to accurately provide analytical expressions for f1 and f2. Therefore, a three-dimensional initial model of the gas collecting chamber 3 and the flow guide device is constructed, and the structural dimensions of the gas collecting chamber 3 and the flow guide device are determined through simulation calculation iterations. During the simulation calculation, it is assumed that the gas flow is in a steady state. The gas inlet 18 adopts the first boundary condition (gas flow rate), and the gas outlet 19 adopts the second boundary condition (gas outlet pressure and velocity gradient). The second-order upwind discrete continuity equation and momentum equation are used as the governing equations. The semi-implicit pressure correction equation method is used for the flow field calculation. The turbulence model adopts the standard Ke two-equation model, and the flow near the wall is approximated by the wall function method.

[0032] The parameter design method for the gas flow guiding device of the present invention specifically includes the following steps: Step 1: Obtain the key structural design parameters of the gas collection chamber 3 and the flow guiding device, and construct a three-dimensional initial model of the gas collection chamber 3 and the flow guiding device.

[0033] An initial model of the gas collection chamber 3 and the flow guiding device was established using 3D modeling software such as ProE. To save computational resources and reduce the amount of calculation, the influence of gravity and other conditions was ignored, and the calculation model was simplified by axisymmetry. The calculation model is 1 / 4 of the actual model region, and the computational domain is shown in the attached figure. Figure 6 As shown.

[0034] Step 2: Set the gas flow rate at the gas inlet 18 of the gas collection chamber 3 in the 3D initial model as the first boundary condition, and set the gas pressure and velocity gradient at the gas outlet 19 as the second boundary condition, as follows: The inlet and outlet boundary conditions of the gas computation domain are set as flow inlet and pressure outlet, respectively. The inlet flow rate is set to 1 / 4 of the design flow rate. The gas inlet flow rate is given by the total gas flow rate during the high-altitude simulation test of the liquid rocket engine, which is the first boundary condition, i.e.: ; Where, The total flow rate of the gas after being cooled by the spray cooler. This refers to the gas flow rate during the operation of a liquid rocket engine.

[0035] The turbulent kinetic energy k and turbulent dissipation rate ε at the gas computational domain inlet are given by the following equation: ; ; Where, Let T be the average velocity of the gas at gas inlet 18. i The turbulent kinetic energy intensity is generally introduced in viscous fluid mechanics, C μ These are constants for the turbulence model, typically taken as C. μ =0.09, where d is the diameter of the gas inlet 18.

[0036] The total pressure at gas outlet 19 is set to the rated pressure at the inlet of the indirect cooler, and it is assumed that the flow at gas outlet 19 is fully developed with no gradient change in the direction of gas flow, which is the second boundary condition, i.e.: ; ; ; ; Where, u, v, w and p These represent the velocity components and pressure of the gas (along the axial, horizontal, and vertical directions) in the gas flow domain. x , y and z For different directions, among which x This indicates the direction of gas flow in front of the flow guide device. z Vertical direction y To and xz The direction of the plane normal.

[0037] Ignoring the effects of convective and radiative heat transfer on gas flow distribution and flow losses, the inner wall of gas collecting chamber 3 is set as an adiabatic wall, and the computational domain symmetry plane is set as a symmetric wall condition, as detailed below. Figure 6 As shown.

[0038] To avoid the influence of the second boundary condition of gas outlet 19 on the calculation results, the gas outlet 19 section is extended. At the same time, a gas orifice plate model is established in the gas outlet 19 section to simulate the downstream pressure drop. The diameter of the gas orifice plate model is the equivalent diameter of the gas in the heat exchanger downstream of the gas outlet 19 of the gas collecting chamber 3. The gas orifice plate model can throttle the gas and simulate the flow resistance of the downstream heat exchanger, which is beneficial to improving the calculation convergence speed.

[0039] Step 3: Mesh the 3D initial model. Simulate the gas flow process of the meshed 3D initial model using the gas flow field continuity equation and momentum equation. Solve the gas flow field continuity equation and momentum equation. Based on the solution results, determine whether the gas flow distribution non-uniformity and gas pressure loss have reached the set thresholds. If not, update the key structural design parameters of the flow guiding device, and repeat the boundary condition setting process and flow guiding simulation process until the gas flow distribution non-uniformity and gas pressure loss reach the set thresholds to obtain the final key structural design parameters. This includes the following steps: (1) Computational domain meshing.

[0040] The computational domain mesh for gas collection chamber 3 and the flow guiding device was divided using computer-aided engineering modeling software such as ICEM (Computer Aided Engineering Modeler). The computational domain mesh was initially generated using an algebraic generation method, and the computational domain mesh near the flow guiding device was smoothed using a partial differential equation method, thereby reducing the impact of mesh quality on the simulation results and further improving the convergence rate of the calculation results.

[0041] (2) Discretize the governing equations.

[0042] The finite volume method is used to discretize the flow field continuity equation and momentum equation near the gas collection chamber 3 and the flow guiding device. The control equations are in a conserved form, as shown in the following equations:

[0043] ; ; ; ; In the formula, ρ is the gas density, u is the gas velocity (u, v, w are the velocity components in the x, y, and z directions), μ is the gas viscosity coefficient, and Su, Sv, and Sw are the viscous dissipation terms during gas flow.

[0044] In the discretization process of the governing equations, the convection term is discretized using a second-order upwind scheme, and the diffusion term is discretized using a central difference scheme.

[0045] (3) Selection of Ke turbulence model and setting of wall function.

[0046] When solving the flow field near the gas collecting chamber 3 and the indirect cooler, the influence of turbulence on the flow field needs to be considered. The standard Keith two-equation turbulence model is used to close the governing equations. In the standard Keith two-equation model, the turbulent viscosity u... t The expression is a function of turbulent kinetic energy k and turbulent dissipation rate ε, as shown in the following equation:

[0047] ; In the formula, ρ is the density of the fuel gas, and C μ These are constants for the turbulence model, typically taken as C. μ =0.09.

[0048] To more accurately obtain the flow field inside the gas collecting chamber 3 and near the wall of the flow guiding device, a wall function is used to approximate the flow near the wall during numerical simulation. When using the wall function method to approximate the flow field inside the gas collecting chamber 3 and near the wall of the flow guiding device, the thickness of the first mesh layer is... The following relationship should be satisfied:

[0049] ; In the formula, C μ These are constants for the turbulence model, typically taken as C. u =0.09, k p For the turbulent kinetic energy of the first layer of grid nodes, μ The viscosity is the dynamic viscosity of the gas.

[0050] If the thickness of the first layer of the generated mesh is... If the above requirements are not met, the mesh needs to be redone until the requirements are met.

[0051] (4) The SIMPLE algorithm is used to calculate the gas flow field.

[0052] The SIMPLE algorithm, a semi-implicit pressure linkage equation method, is used. The control equations and turbulent kinetic energy and dissipation rate equations of the gas are solved to obtain the pressure and velocity distribution in the flow field, and then the non-uniformity of the gas outlet flow distribution and the pressure loss at the gas inlet and outlet are obtained.

[0053] If the above indicators meet the design requirements under rated operating conditions, repeat the above process to calculate the indicators under non-rated operating conditions such as high and low operating conditions and high and low mixed ratios. If they do not meet the requirements, revise the design model until the parameter design results meet the design indicators under various operating conditions.

[0054] In summary, this method can uniformly distribute the high-temperature (approximately 1000℃), high-speed (approximately 0.8 Ma), corrosive hydrazine-based fuel gas, and nitrogen oxide vapor generated during the experiment to multiple sets of parallel indirect coolers. This achieves uniform distribution of high-flow-density, high-enthalpy fuel gas generated during high-altitude simulation tests of liquid rocket engines with a capacity of 10 kN or higher, while ensuring that the fuel gas flow loss meets the overall performance indicators of the test system.

[0055] The above-described embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited thereto. Any simple changes or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention shall fall within the scope of protection of the present invention.

Claims

1. A gas flow guiding device, located within the gas collection chamber (3) of a liquid rocket engine, wherein the gas collection chamber (3) is a hollow cylinder, characterized in that, The gas collection chamber (3) has a gas inlet (18) on one side and multiple gas outlets (19) symmetrically arranged on the other side. Each gas outlet (19) is connected to a set of indirect cooling devices. The gas guiding device includes: First guide vane (1); The second guide plate (2) is fixedly connected at one end to the first guide plate (1). The joint between the first guide plate (1) and the second guide plate (2) is arranged at a preset opening angle. The center line of the opening angle coincides with the center line of the gas inlet (18) of the gas collecting chamber (3). The opening of the opening angle faces the gas outlet (19). The third guide plate (4) and the fourth guide plate (5) are respectively set on both sides of the opening angle, and are both set parallel to the axis of the gas collection chamber (3). The third guide plate (4) is connected to the other end of the first guide plate (1), and the fourth guide plate (5) is connected to the other end of the second guide plate (2). The lower ends of the first guide plate (1), the second guide plate (2), the third guide plate (4) and the fourth guide plate (5) are all fixedly connected to the inner wall of the gas collection chamber (3).

2. The gas flow guiding device according to claim 1, characterized in that, The gas flow guiding device further includes a cooling structure, which includes: The enclosed assembly, together with the first guide plate (1), the second guide plate (2), the third guide plate (4) and the fourth guide plate (5), forms a cooling water tank; The reinforcement component is located outside the cooling water tank and is fixedly connected to the enclosure component. Water supply pipe (6) is located at the lower end of the enclosure component and is connected to the enclosure component; Two drain pipes (7) are located at the upper end of the enclosure and are connected to the enclosure.

3. The gas flow guiding device according to claim 2, characterized in that, The enclosed component includes: Two cone plates (8) are arranged parallel to the first guide plate (1) and the second guide plate (2) respectively, and the two cone plates (8) are fixedly connected at their closest ends; Two flat plates (9) are arranged parallel to the third guide plate (4) and the fourth guide plate (5), respectively; one end of each of the two flat plates (9) is fixedly connected to the opposite end of each of the two cone plates (8); The upper base plate (10) is connected to the upper ends of two cone plates (8) and two flat plates (9) on one side; the two drain pipes (7) are connected to the upper base plate (10); The bottom plate (11) is connected to the upper ends of two cone plates (8) and two flat plates (9) on one side, and is fixedly connected to the inner wall of the gas collection chamber (3) on the other side; the water supply pipe (6) is connected to the bottom plate (11); The top plate (12) is fixedly connected to the first guide plate (1), the second guide plate (2), the third guide plate (4) and the fourth guide plate (5) on one side, and fixedly connected to the other side of the bottom plate (10) on the other side. There is a gap between the top plate (12) and the gas collection chamber. The first side sealing plate (13) and the second side sealing plate (14) are respectively disposed on the outside of the third guide plate (4) and the fourth guide plate (5). The upper end of the first side sealing plate (13) is connected to the upper top plate (12), the lower end is connected to the inner wall of the gas collection chamber (3), and the two sides are respectively connected to the third guide plate (4) and a plate (9); the upper end of the second side sealing plate (14) is connected to the upper top plate (12), the lower end is connected to the inner wall of the gas collection chamber (3), and the two sides are respectively connected to the fourth guide plate (5) and another plate (9).

4. The gas flow guiding device according to claim 3, characterized in that, The reinforcement components include: Two first stiffener plates (15) are arranged vertically at intervals on one side of the opening angle, and each side is connected to two flat plates (9); Two second stiffeners (16) are spaced apart in the horizontal direction and are perpendicular to the first stiffener (15) located above. One end of each of the two second stiffeners (16) is connected to two flat plates (9). Two third stiffeners (17) are spaced apart in the horizontal direction and are perpendicular to the first stiffener (15) located below. One end of each of the two third stiffeners (17) is connected to two flat plates (9).

5. The gas flow guiding device according to claim 1, characterized in that, The gas inlet (18) is connected to the diffuser.

6. The gas flow guiding device according to claim 1, characterized in that, The gas collection chamber (3) is made of Q345r high-temperature resistant carbon steel, and the flow guiding device is made of S321 high-temperature resistant stainless steel. A high-temperature resistant and erosion-resistant coating is sprayed on the windward side of the flow guiding device.

7. A parameter design method for a gas flow guiding device based on any one of claims 1-6, characterized in that, The steps include: Obtain the key structural design parameters of the gas collection chamber (3) and the flow guiding device, and construct a three-dimensional initial model of the gas collection chamber (3) and the flow guiding device; The gas flow rate at the gas inlet (18) of the gas collection chamber (3) of the three-dimensional initial model is set as the first boundary condition, and the gas pressure and velocity gradient at the gas outlet (19) are set as the second boundary condition. The three-dimensional initial model is meshed, and the gas flow field continuity equation and momentum equation are used to simulate the gas flow process of the meshed three-dimensional initial model. The gas flow field continuity equation and momentum equation are solved, and the gas flow distribution non-uniformity and gas pressure loss are judged based on the solution results. If not, the key parameters of the flow guiding device are updated, and the boundary condition setting process and flow guiding simulation process are repeated until the gas flow distribution non-uniformity and gas pressure loss reach the set threshold, and the final key parameters of the structural design are obtained.

8. The parameter design method for the gas flow guiding device according to claim 7, characterized in that, The key parameters of the structural design include the opening angle of the first guide plate (1) and the second guide plate (2), the distance between the unconnected ends of the first guide plate (1) and the second guide plate (2), the distance between the far end of the third guide plate (4) and the fourth guide plate (5), the distance between the axis of the third guide plate (4) and the fourth guide plate (5) and the gas collection chamber (3), and the distance between two adjacent gas outlets (19).

9. The parameter design method for the gas flow guiding device according to claim 7, characterized in that, The formula for calculating the first boundary condition is as follows: ； Where, This refers to the total flow rate of the gas after being cooled by the spray water. This refers to the gas flow rate during the operation of a liquid rocket engine. This refers to the flow rate of the spray cooling water.

10. The parameter design method for the gas flow guiding device according to claim 7, characterized in that, The second boundary condition is as follows: ； ； ； ； Where, u , v , w and p These represent the gas velocity component and pressure within the gas flow domain. x , y and z For different directions.

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