CN112100734A - Method for determining influence of vacuum plume on equipment with any configuration - Google Patents
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Abstract
The invention discloses a method for determining the influence of a vacuum plume on equipment with any configuration, which decouples the calculation of the vacuum plume and the calculation of the impact of flow on the surface of the equipment, and firstly obtains flow field parameters of an undisturbed state near the wall surface of the equipment; then, by constructing a device surface grid, obtaining a grid central point flow parameter by adopting an interpolation method; and finally, obtaining the impact pressure, the heat flow density and the mass flow density distribution of the plume acting on the equipment wall surface grid point by correcting the Newton theory and selecting a gas and equipment surface action model suitable for the equipment wall surface condition. The method solves the problems of difficult plume analysis modeling, more time consumption for calculation and the like of the vacuum thruster of the equipment with the complex configuration, can quickly evaluate the plume influence of the equipment with the complex configuration, and provides a design basis for the position adjustment and the thermal protection design of the equipment.
Description
Technical Field
The invention belongs to the technical field of analysis of vacuum plume force, heat and pollution effects of thrusters (engines), and provides a method for determining the influence of a vacuum plume on equipment with any configuration.
Background
The plume effect analysis of the thruster is an important link for developing the spacecraft. During the working period of the attitude and orbit control thruster, the generated plume can impact the surface of the spacecraft and generate disturbance force and moment, so that the precision and the stability of a spacecraft control system are influenced; large heat flow may be generated on the surface of the equipment, and the working performance of the equipment and the design of a thermal protection system are influenced; the sensor and the optical lens can be polluted, harmful effects are generated on the optical surface, the thermal control coating and the surface of the solar cell array, the equipment layout of the star catalogue and the design of a protection system are influenced, and therefore the working performance and the service life of the spacecraft are directly influenced.
Currently, the vacuum plume effect analysis mainly comprises a direct simulation Monte Carlo method (DSMC) and an engineering algorithm. The basic idea of the DSMC is to replace a large number of real gas molecules with a plurality of finite simulation molecules, and achieve the purpose of solving the real gas flow problem by randomly sampling the simulation molecules and tracking the motion trail of the simulation molecules. The DSMC method must use a sufficient number of simulated molecules to adequately represent the distribution of real gas molecules in the flow field grid. The characteristic determines that the calculation precision of the DSMC method is high, but the calculation amount and the memory demand are large, and the calculation time is long. In the engineering calculation of complex configuration, multiple working conditions and fast requirements, the calculation efficiency of the DSMC method is a key factor for restricting the engineering application.
For the vacuum plume effect analysis of the thruster, an engineering algorithm is used for calculating and decoupling the effect of a thruster plume flow field and the effect of a plume impacting the surface of the spacecraft, a flow field grid and an equipment surface grid are respectively constructed, then a Computational Fluid Dynamics (CFD) and point source model are used for obtaining the plume flow field, and finally a plume impacting spacecraft surface characteristic model is used for obtaining the plume impacting pressure, the heat flow and the mass flow density. The key of the engineering method is to decouple the flow field three-dimensional grid and the equipment surface grid, so that the construction of the equipment surface grid with a complex configuration becomes possible.
At present, in the existing vacuum plume engineering analysis method, the geometric features of the spacecraft body and the surface equipment are simplified and described through a primary/secondary curved surface or a combination thereof, and appropriate node arrangement is performed on the two-dimensional direction of the curved surface describing the geometric features of the equipment, so that division of a surface mesh is completed. For devices, such as rib antennas, whose surfaces cannot be described by a primary/secondary curved surface or a combination thereof, the geometric characteristics of the devices cannot be accurately reflected by a relatively close primary/secondary curved surface, so that the plume calculation result is biased.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the method overcomes the defects and limitations of the prior art, decouples the calculation of the vacuum plume field and the calculation of the impact of the flow on the surface of the equipment, provides a grid construction method suitable for any configuration equipment (such as a rib-shaped antenna) and solves the problem of plume effect analysis of the equipment with the complex configuration of the spacecraft.
The technical solution of the invention is as follows: a method for determining the influence of a vacuum plume on a device with any configuration comprises the following steps:
1) obtaining a combustion product balance component and a thermodynamic parameter thereof by utilizing a thruster combustion chamber thermodynamic calculation model according to the total pressure and the fuel proportion of the thruster combustion chamber;
2) establishing two-dimensional axial symmetry flow field grids in the inner area and the outer area of the thruster, balancing the combustion products, dividing the flow field grids into flowing working media, and calculating the inner flow field and the outer flow field of the thruster;
3) and extracting and reserving curved surface characteristics of the star catalogue equipment according to the PROE model of the star catalogue equipment of the spacecraft. According to the curved surface characteristics of the star catalogue equipment, a geometric model of a three-dimensional shell of the star catalogue equipment is built, and the equipment surface is subjected to meshing;
4) traversing the grid point data obtained in the step 3) and the internal and external flow field data obtained in the step 2) to obtain flow field characteristic parameters at the central point of the grid;
5) and determining the influence of the vacuum plume on plume force, heat and pollution on equipment with complex configuration according to a modified Newton theory and a Knudsen model.
The specific process of the step 1) is as follows: giving initial combustion temperature and combustion product composition according to experience, solving a mass conservation equation and a chemical equilibrium equation by using a minimum Gibbs free energy method, and calculating to obtain a combustion product equilibrium component under the given temperature and pressure; iteratively solving the adiabatic combustion temperature and the combustion product balance component at the adiabatic combustion temperature by adopting a Newton-Raphson method based on the assumption that the total enthalpy of the adiabatic-chemical equilibrium model is unchanged; and under the assumption of local chemical balance or fixed components, calculating to obtain the thermodynamic parameters of the combustion product balance components, including gas pressure, density, molar mass, constant pressure specific heat and specific heat ratio.
The specific process of the step 2) is as follows: for the flow field in the thruster, assuming laminar flow, calculating subsonic or supersonic flow in the thruster by using an N-S equation solver; neglecting viscosity in the area near the external nozzle of the propeller, and calculating a flow field by using an Euler equation solver; and for the area, far away from the nozzle, outside the thruster, calculating the flow field by adopting a point source method based on engineering experience.
The area near the nozzle outside the thruster is the area inside the radius from the throat of the nozzle 100, and the area far away from the nozzle outside the thruster is the area outside the radius from the throat of the nozzle 100.
The specific process of the step 3) is as follows: for spacecraft star surface equipment, simplifying the spacecraft star surface equipment into a three-dimensional shell consisting of curved surfaces according to a PROE model; the curved surfaces forming the shell are divided into two categories, namely a simple geometric shape curved surface and a complex geometric shape curved surface; the Hua simple geometric shape curved surface is defined as a curved surface which can be analytically described by a first-order equation and a second-order equation, wherein the specific form of the first-order equation is shown in a formula (1), and the specific form of the second-order equation is shown in a formula (2); the complex geometric shape curved surface is defined as a curved surface which cannot be analytically described by the formula (1) and the formula (2); when the 14 coefficients in the formula (1) and the formula (2) respectively take different values, different curved surface types are represented; the method comprises the following steps of (1) finishing quadric surface mesh division by using triangular meshes and quadrilateral meshes by defining proper node number in a two-dimensional direction of a curved surface; for the complex curved surface which cannot be analyzed and described by the formula (1) and the formula (2), importing the complex curved surface into PATRAN software, and completing complex curved surface mesh division by using an automatic division tool Paver; and calculating the coordinates of the central points of the grids by utilizing three nodes aiming at the triangular grids or four nodes aiming at the quadrilateral grids according to the nodes corresponding to the surface grids, and calculating the normal direction of the plane of the grids by utilizing the plane geometric relationship.
c1x+c2y+c3z+d＝0 (4)
a11x2+a22y2+a33z2+2a12xy+2a13xz+2a23yz+b1x+b2y+b3z+c＝0 (5)
Wherein c1, c2, c3 and d are equation of the first time coefficients; a11, a22, a33, a12, a13, a23, b1, b2, b3 and c are quadratic coefficients.
The specific process of the step 4) is as follows: traversing the grid point data obtained in the step 3) and the flow field data obtained in the step 2), finding out 4 flow field data points closest to the grid center point, calculating the distances between the 4 flow field data points and the grid center point, and obtaining flow field parameters including pressure, flow velocity, density and temperature at the grid center point by taking the reciprocal of the distance as weight and carrying out weighted average.
The grid center point flow field parameter weighting algorithm is as follows:
where l1, l2, l3, and l4 are the distances of the nearest 4 flow field data points from the center point of the grid;
o and a1, a2, A3, a4 represent flow field characteristic parameters for the grid center point and its 4 nearest flow field data points, respectively.
The specific process of the step 5) is as follows: according to the flow field parameter of the central point of the surface grid, the impact pressure P of the central point of the surface grid is obtained by utilizing the modified Newton theoryimp(ii) a Obtaining the force of the plume acting on the equipment with the complex configuration through the pressure integration of the equipment surface grids; the overall acting force of the plume on the spacecraft is obtained by summing all the devices influenced by the plume acting region; further setting a mass center point of the spacecraft to obtain a disturbance torque generated by the plume on the spacecraft;
for the calculation of plume heat influence, firstly, describing the action form of plume gas molecules and the surface of equipment by adopting a Knudsen model; the Knudsen model sets 3 motion patterns of the gas at the surface of the equipment: the absorption, diffuse reflection and specular reflection are respectively determined by an absorption coefficient beta, a diffuse reflection coefficient alpha and a specular reflection coefficient tau, and meet the condition that beta + alpha + tau is 1; calculating to obtain the thermal influence q of the plume on the wall surface; integrating the grid area by the equipment surface grid heat influence to obtain the total heating quantity of the plume to the equipment; dividing the total heating amount by the surface area of the device to obtain the average heating amount of the plume on the device;
obtaining the plume mass flow density at the surface grid by using a formula (6) according to the speed and the density of the central point of the surface grid
Integrating the mass flow density of the device surface grid with the grid area to obtain the total pollution amount of the plume to the device; the total contamination was divided by the surface area of the device to give the average contamination of the device with the plume.
Wherein rho is the density of the central point of the surface grid; v is the speed of the center point of the surface grid; theta is the local angle of incidence and is defined as the angle between the direction of the velocity and the tangent to the grid plane.
Obtaining the impact pressure P of the center point of the surface grid by using the modified Newton theoryimpThe concrete formula of (1) is as follows:
Pimp＝Cp(P2-P∞)sin2θ+P∞
wherein, CpIs the pressure coefficient; p2Is the pitot pressure, i.e. the stagnation pressure after the forward shock; p∞Is the incoming flow pressure; theta is the local angle of incidence and is defined as the angle between the direction of the velocity and the tangent to the grid plane.
The specific method for calculating the thermal influence q of the plume on the wall surface comprises the following steps:
q＝α(qinto-qInverse direction)
Wherein q isIntoIs the total heat flow of incident gas molecules; q. q.sInverse directionIs the total heat flow of the reflecting gas molecules; alpha is the diffuse reflection coefficient of the interaction of plume gas molecules with the surface of the device.
Compared with the prior art, the invention has the advantages that:
(1) according to the method, the calculation of the vacuum plume field and the calculation of the impact of the flow on the surface of the equipment are decoupled, the calculation efficiency of the influence of the plume on the equipment with a complex configuration is greatly improved, and the engineering calculation requirements of the iterative analysis of multiple working conditions and configuration changes can be met.
(2) Compared with the method for constructing the spacecraft equipment surface mesh by using the primary curved surface and the secondary curved surface, the method can solve the problem of constructing the spacecraft equipment surface mesh by using any complex configuration equipment surface mesh, and has universality and generality.
(3) Compared with the conventional method that the plume surface grid model of the spacecraft can be built only by manual measurement and block building, the method can integrally generate the plume surface grid model based on the existing PROE and CAD models of the spacecraft equipment, and the modeling accuracy and efficiency are improved.
(4) Based on the improvement of modeling accuracy, the analysis precision of plume force, heat and pollution effects is also improved.
Drawings
FIG. 1 is a flow chart of an engineering analysis method for vacuum plume force, heat and pollution effects of a thruster suitable for spacecraft equipment with a complex configuration, provided by an embodiment of the invention;
FIG. 2 is a grid diagram of an internal and external flow field of the 5N thruster;
FIG. 3 is a vector diagram of the velocities of the inner and outer flow fields of the 5N thruster;
FIG. 4 is a flow chart of a complex configuration spacecraft equipment surface grid construction method and a surface grid flow field parameter interpolation process;
FIG. 5 is a schematic diagram of a complex configuration equipment face grid;
FIG. 6 is a schematic diagram of a flow field parameter interpolation method for a center point of a surface mesh;
Detailed Description
Taking the plume influence analysis of the 5N thruster on the rib antenna of the star complex geometry device as an example, the invention will be further described in detail with reference to the attached drawings:
FIG. 1 shows a flow chart of a method for determining the influence of a vacuum plume on an arbitrarily configured device.
Mainly comprises the following steps.
1) Given the fuel composition of the 5N thruster, the main component is anhydrous hydrazine (N)2H4) Setting total pressure P of combustion chamber01.1 MPa. Empirically given an initial combustion temperature T0850 ℃ and combustion products, including H2、N2And NH3. And solving a mass conservation equation and a chemical equilibrium equation by using a minimum Gibbs free energy method, and calculating the equilibrium components of the combustion products under the given temperature and pressure conditions. And (3) iteratively solving the adiabatic combustion temperature and the combustion product equilibrium component at the adiabatic combustion temperature by adopting a Newton-Raphson method based on the assumption that the total enthalpy of the adiabatic-chemical equilibrium model is unchanged. Under the assumption of local chemical equilibrium or fixed composition, the thermodynamic parameters of combustion product equilibrium component mixing, including gas density, molar mass, specific heat at constant pressure, specific heat ratio and the like, are calculated. Two specific positions outside the throat part and the outlet of the thruster are selected, and the balance components and the thermodynamic parameters of the combustion products are given as shown in the following table.
TABLE 1 Combustion products equilibrium composition
TABLE 2 thermal parameters of combustion products
2) According to the geometrical size of the thruster, the inner flow field and the outer flow field of the 5N thruster are divided into grids according to the geometrical size of the thruster, the diameter of the throat and the diameter of an outlet, the distance from the throat to the outlet, the expansion characteristic of a nozzle, the shape of a lip flanging and the like, which is shown in figure 2. And (4) in the propeller, considering the viscosity effect, and solving an N-S equation by adopting a finite volume method to obtain the subsonic velocity or supersonic velocity flow in the propeller. For the flow of the area near the external nozzle of the propeller, the viscosity effect can be ignored, and the flow can be obtained by adopting a method of numerically solving an Ev lambda rho equation. For regions away from the nozzle, the solution is performed using an engineering method point source model. The point source model is implemented by defining a freezing surface in the flow field, arranging a certain number of free molecular point sources on the freezing surface, and the flow parameters of any point in the flow field can be regarded as all the free molecular point sources to generate superposition of the flow field at the point. The density ρ of the flow field generated by the free molecular point source follows the radiation attenuation law, see equation (7).
In the formula (I), the compound is shown in the specification,
expanding the limiting velocity for the plume; σ is the nozzle throat flow rate; rho is the distance from the outlet of the spray pipe; θ is the angle from the plume axis; thetaΛSpread angle of pi- μm; gamma is the specific heat ratio of the gas; phi (theta) is a function of the angle from the plume axis.
Due to the difference in the basic flow parameters, phi (theta) has different expressions in the plume core region and the boundary layer expansion region. The expression of φ (θ) in the plume core region is:
wherein, theta0Is the plume core region flow limit deflection angle; theta∞Is the jet flow limit deflection angle. In the boundary layer expansion zone, a coefficient β is introduced and φ (θ) is considered to decay exponentially in that zone. The expression of φ (θ) in the boundary layer expansion region is:
f(θ)＝f(θ0)exp[-β(θ-θ0)]θ0≤θ≤θ∞ (10)
other physical quantities in the flow field, e.g. pressure pi, temperature T and velocity
And (5) solving according to the one-dimensional isentropic relation. The flow field parameter file is 5 Ν. The flow field velocity vectors are shown in figure 3.
3) Taking a star catalogue device rib antenna as an example, a three-dimensional surface mesh construction process of a complex configuration device is described, and a flow is shown in fig. 4. The antenna support rod, the rotating shaft and the motor device are simple in geometric appearance, and the surfaces of the antenna support rod, the rotating shaft and the motor device can be simplified to be constructed by a one-quadratic surface or a combination of one-quadratic surfaces. The antenna rib-shaped spoke has a complex geometric shape and cannot be constructed by simple primary/secondary curved surfaces or a combination thereof, so that the complex curved surface is imported into PATRAN software by extracting and only retaining the geometric characteristics of the rib surface by using the conventional antenna rib-shaped spoke PROE file, and the mesh division of the complex curved surface is completed by using an automatic division tool Paver. The completed star rib antenna device planar grid is shown in fig. 5. And saving the mesh type and the corresponding node information, calculating the coordinates of the center points of the meshes by utilizing the weighted average of three nodes (aiming at triangular meshes) or four nodes (aiming at quadrangular meshes) according to the corresponding nodes of the surface meshes, and calculating the normal direction of the mesh plane by utilizing the plane geometric relationship. Mesh file stores grid number, center point coordinate and plane normal direction data.
4) Traversing a rib-shaped antenna surface grid data file antenna.mesh and a flow field file 5N.flow, traversing and searching the flow field file according to the coordinates of the center point of the grid, and finding 4 flow field information points closest to the surface element. As shown in fig. 6. Assume that the 4 flow field points are separated from the center O point by distances l1, l2, l3, l4, respectively. Then the flow field information of the center O point of the surface element grid is obtained by interpolation according to the following formula:
wherein
O and a1, a2, A3, a4 represent flow field characteristic parameters (e.g., density, velocity, pressure, temperature, etc.) for the grid center point and the 4 nearest flow field point data points.
5) According to the flow field parameter of the central point of the surface grid, the impact pressure P of the central point of the surface grid is obtained by utilizing the modified Newton theoryimp(ii) a Obtaining the force (N) of the plume acting on the equipment with the complex configuration through the pressure integral of the surface grid of the equipment with the complex configuration; and (3) obtaining the arranging acting force (N) of the plume on the spacecraft by summing all devices influenced by the plume acting region. And further setting a mass center point of the spacecraft to obtain the plume disturbance moment (N.m).
Pimp＝Cp(P2-P∞)sin2θ+P∞ (12)
Wherein, CpIs the pressure coefficient; p2Is the pitot pressure, i.e. the stagnation pressure after the forward shock; p∞Is the incoming flow pressure; θ is the local angle of incidence, defined as the angle between the plume velocity direction and the tangent of the veil surface.
According to the flow field parameters at the surface grid, parameters of a plume gas and equipment wall surface action model (Knudsen) are set, and the adsorption coefficient gamma, the diffuse reflection coefficient alpha and the specular reflection coefficient tau meet the formula (12). The gas molecules that are specularly reflected do not exchange energy with the wall. Adsorption is assumed to occur infrequently and is negligible. The thermal influence q of the plume on the wall surface is calculated by the following equation (13). And integrating the heat flux density of the device surface grid to obtain the total heating efficiency of the plume on the device. The total heating was divided by the device surface area to determine the average heat flow effect of the plume on the device.
β+α+τ＝1 (13)
q＝α(qInto-qInverse direction) (14)
Wherein gamma, beta and tau are respectively an adsorption coefficient, a diffuse reflection coefficient and a specular reflection coefficient; q. q.sIntoIs the total heat flow of incident gas molecules; q. q.sInverse directionIs the total heat flow of the reflecting gas molecules.
And (4) obtaining the plume mass flow density at the surface grid according to the central point speed and the density of the surface grid by using the formula (14). And integrating the mass flow density of the device surface grid to the grid area to obtain the total pollution amount of the plume to the device. The total contamination was divided by the surface area of the device to give the average contamination of the device with the plume.
Wherein rho is the density of the central point of the surface grid; v is the speed of the center point of the surface grid; theta is the local angle of incidence and is defined as the angle between the direction of the velocity and the tangent to the grid plane.
The invention provides a method for analyzing the influence of vacuum thruster plume on equipment with any configuration. The method decouples the calculation of the vacuum plume field and the calculation of the impact of flow on the wall surface of equipment, and firstly obtains the flow field parameters of the undisturbed state near the wall surface of the equipment with any configuration; then, by constructing a surface grid of the equipment with the complex configuration, a grid point flow parameter is obtained by adopting an interpolation method; and finally, correcting the Newton theory and selecting a surface action model suitable for the wall surface of the equipment to obtain the impact pressure, the heat flow density and the mass flow density distribution of the plume acting on the equipment wall surface grid point. The method solves the problems of difficult plume analysis modeling, more time consumption for calculation and the like of the vacuum thruster with the complex configuration, can quickly evaluate the plume influence of equipment with the complex configuration, and provides reference for equipment position adjustment and heating protection design.
The above-described embodiments are merely preferred embodiments of the present invention, and general changes and substitutions by those skilled in the art within the technical scope of the present invention are included in the protection scope of the present invention.
Claims (10)
1. A method for determining the influence of a vacuum plume on a device with any configuration is characterized by comprising the following steps:
1) obtaining a combustion product balance component and a thermodynamic parameter thereof by utilizing a thruster combustion chamber thermodynamic calculation model according to the total pressure and the fuel proportion of the thruster combustion chamber;
2) establishing two-dimensional axial symmetry flow field grids in the inner area and the outer area of the thruster, balancing the combustion products, dividing the flow field grids into flowing working media, and calculating the inner flow field and the outer flow field of the thruster;
3) and extracting and reserving curved surface characteristics of the star catalogue equipment according to the PROE model of the star catalogue equipment of the spacecraft. According to the curved surface characteristics of the star catalogue equipment, a geometric model of a three-dimensional shell of the star catalogue equipment is built, and the equipment surface is subjected to meshing;
4) traversing the grid point data obtained in the step 3) and the internal and external flow field data obtained in the step 2) to obtain flow field characteristic parameters at the central point of the grid;
5) and determining the influence of the vacuum plume on plume force, heat and pollution on equipment with complex configuration according to a modified Newton theory and a Knudsen model.
2. The method of claim 1 for determining the effect of a vacuum plume on an arbitrarily configured device, wherein: the specific process of the step 1) is as follows: giving initial combustion temperature and combustion product composition according to experience, solving a mass conservation equation and a chemical equilibrium equation by using a minimum Gibbs free energy method, and calculating to obtain a combustion product equilibrium component under the given temperature and pressure; iteratively solving the adiabatic combustion temperature and the combustion product balance component at the adiabatic combustion temperature by adopting a Newton-Raphson method based on the assumption that the total enthalpy of the adiabatic-chemical equilibrium model is unchanged; and under the assumption of local chemical balance or fixed components, calculating to obtain the thermodynamic parameters of the combustion product balance components, including gas pressure, density, molar mass, constant pressure specific heat and specific heat ratio.
3. The method of claim 1 for determining the effect of a vacuum plume on an arbitrarily configured device, wherein: the specific process of the step 2) is as follows: for the flow field in the thruster, assuming laminar flow, calculating subsonic or supersonic flow in the thruster by using an N-S equation solver; neglecting viscosity in the area near the external nozzle of the propeller, and calculating a flow field by using an Euler equation solver; and for the area, far away from the nozzle, outside the thruster, calculating the flow field by adopting a point source method based on engineering experience.
4. The method of claim 3, wherein the influence of the vacuum plume on the device with any configuration is determined by: the area near the nozzle outside the thruster is the area inside the radius from the throat of the nozzle 100, and the area far away from the nozzle outside the thruster is the area outside the radius from the throat of the nozzle 100.
5. The method of claim 1 for determining the effect of a vacuum plume on an arbitrarily configured device, wherein: the specific process of the step 3) is as follows: for spacecraft star surface equipment, simplifying the spacecraft star surface equipment into a three-dimensional shell consisting of curved surfaces according to a PROE model; the curved surfaces forming the shell are divided into two categories, namely a simple geometric shape curved surface and a complex geometric shape curved surface; the Hua simple geometric shape curved surface is defined as a curved surface which can be analytically described by a first-order equation and a second-order equation, wherein the specific form of the first-order equation is shown in a formula (1), and the specific form of the second-order equation is shown in a formula (2); the complex geometric shape curved surface is defined as a curved surface which cannot be analytically described by the formula (1) and the formula (2); when the 14 coefficients in the formula (1) and the formula (2) respectively take different values, different curved surface types are represented; the method comprises the following steps of (1) finishing quadric surface mesh division by using triangular meshes and quadrilateral meshes by defining proper node number in a two-dimensional direction of a curved surface; for the complex curved surface which cannot be analyzed and described by the formula (1) and the formula (2), importing the complex curved surface into PATRAN software, and completing complex curved surface mesh division by using an automatic division tool Paver; and calculating the coordinates of the central points of the grids by utilizing three nodes aiming at the triangular grids or four nodes aiming at the quadrilateral grids according to the nodes corresponding to the surface grids, and calculating the normal direction of the plane of the grids by utilizing the plane geometric relationship.
c1x+c2y+c3z+d＝0 (1)
a11x2+a22y2+a33z2+2a12xy+2a13xz+2a23yz+b1x+b2y+b3z+c＝0 (2)
Wherein c1, c2, c3 and d are equation of the first time coefficients; a11, a22, a33, a12, a13, a23, b1, b2, b3 and c are quadratic coefficients.
6. The method of claim 1 for determining the effect of a vacuum plume on an arbitrarily configured device, wherein: the specific process of the step 4) is as follows: traversing the grid point data obtained in the step 3) and the flow field data obtained in the step 2), finding out 4 flow field data points closest to the grid center point, calculating the distances between the 4 flow field data points and the grid center point, and obtaining flow field parameters including pressure, flow velocity, density and temperature at the grid center point by taking the reciprocal of the distance as weight and carrying out weighted average.
7. The method of claim 6, wherein the influence of the vacuum plume on the device with any configuration is determined by: the grid center point flow field parameter weighting algorithm is as follows:
where l1, l2, l3, and l4 are the distances of the nearest 4 flow field data points from the center point of the grid;
o and a1, a2, A3, a4 represent flow field characteristic parameters for the grid center point and its 4 nearest flow field data points, respectively.
8. The method of claim 1 for determining the effect of a vacuum plume on an arbitrarily configured device, wherein: the specific process of the step 5) is as follows: according to the flow field parameter of the central point of the surface grid, utilizing and repairingObtaining the impact pressure P of the center point of the surface grid by positive Newton theoryimp(ii) a Obtaining the force of the plume acting on the equipment with the complex configuration through the pressure integration of the equipment surface grids; the overall acting force of the plume on the spacecraft is obtained by summing all the devices influenced by the plume acting region; further setting a mass center point of the spacecraft to obtain a disturbance torque generated by the plume on the spacecraft;
for the calculation of plume heat influence, firstly, describing the action form of plume gas molecules and the surface of equipment by adopting a Knudsen model; the Knudsen model sets 3 motion patterns of the gas at the surface of the equipment: the absorption, diffuse reflection and specular reflection are respectively determined by an absorption coefficient beta, a diffuse reflection coefficient alpha and a specular reflection coefficient tau, and meet the condition that beta + alpha + tau is 1; calculating to obtain the thermal influence q of the plume on the wall surface; integrating the grid area by the equipment surface grid heat influence to obtain the total heating quantity of the plume to the equipment; dividing the total heating amount by the surface area of the device to obtain the average heating amount of the plume on the device;
obtaining the plume mass flow density at the surface grid by using a formula (4) according to the speed and the density of the central point of the surface grid
Integrating the mass flow density of the device surface grid with the grid area to obtain the total pollution amount of the plume to the device; dividing the total pollution amount by the surface area of the equipment to obtain the average pollution amount of the plume to the equipment;
wherein rho is the density of the central point of the surface grid; v is the speed of the center point of the surface grid; theta is the local angle of incidence and is defined as the angle between the direction of the velocity and the tangent to the grid plane.
9. The method of claim 8, wherein the influence of the vacuum plume on the device with any configuration is determined by: obtaining the impact pressure P of the center point of the surface grid by using the modified Newton theoryimpThe concrete formula of (1) is as follows: pimp＝Cp(P2-P∞)sin2θ+P∞
Wherein, CpIs the pressure coefficient; p2Is the pitot pressure, i.e. the stagnation pressure after the forward shock; p∞Is the incoming flow pressure; theta is the local angle of incidence and is defined as the angle between the direction of the velocity and the tangent to the grid plane.
10. The method of claim 9 for determining the effect of a vacuum plume on an arbitrarily configured device, wherein: the specific method for calculating the thermal influence q of the plume on the wall surface comprises the following steps:
q＝α(qinto-qInverse direction)
Wherein q isIntoIs the total heat flow of incident gas molecules; q. q.sInverse directionIs the total heat flow of the reflecting gas molecules; alpha is the diffuse reflection coefficient of the interaction of plume gas molecules with the surface of the device.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112699623A (en) * | 2021-03-24 | 2021-04-23 | 中国空气动力研究与发展中心计算空气动力研究所 | High-precision heat flow calculation method based on unstructured grid regularized reconstruction technology |
| CN113340603A (en) * | 2021-03-22 | 2021-09-03 | 北京空间飞行器总体设计部 | System and method for testing vacuum plume force thermal effect of engine |
| CN113657010A (en) * | 2021-10-21 | 2021-11-16 | 山东神力索具有限公司 | Meshing adjustment method and system for rigging model and electronic equipment |
| CN113987975A (en) * | 2021-11-12 | 2022-01-28 | 北京航空航天大学 | Plume process simulation method and device, electronic equipment and storage medium |
| CN115618171A (en) * | 2022-06-06 | 2023-01-17 | 北京理工大学 | Propellant combustion balance product solving method based on homotopy algorithm |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103217269A (en) * | 2013-02-28 | 2013-07-24 | 北京空间飞行器总体设计部 | Determination method for influence on star catalogue device by 10-N thruster plume |
| CN103279616A (en) * | 2013-06-03 | 2013-09-04 | 西安近代化学研究所 | Virtual test method for influence of solid propellant smoke upon visible-light guidance signals |
| CN104376151A (en) * | 2014-10-30 | 2015-02-25 | 北京宇航系统工程研究所 | Vacuum disturbance pilot flow field simulation method for rocket engine |
| US20170024496A1 (en) * | 2015-07-22 | 2017-01-26 | The Boeing Company | Methods and apparatus to model thermal mixing for prediction of multi-stream flows |
| WO2017084106A1 (en) * | 2015-11-20 | 2017-05-26 | 田川 | System and method for numerical simulation of aircraft flow field |
| CN108241303A (en) * | 2018-01-10 | 2018-07-03 | 北京航空航天大学 | A kind of Vacuum Plume effect Method for Accurate Calculation |
| CN110132606A (en) * | 2019-05-28 | 2019-08-16 | 北京航空航天大学 | Thruster plume parameter measurement system, method and device |
-
2020
- 2020-07-27 CN CN202010732677.XA patent/CN112100734B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103217269A (en) * | 2013-02-28 | 2013-07-24 | 北京空间飞行器总体设计部 | Determination method for influence on star catalogue device by 10-N thruster plume |
| CN103279616A (en) * | 2013-06-03 | 2013-09-04 | 西安近代化学研究所 | Virtual test method for influence of solid propellant smoke upon visible-light guidance signals |
| CN104376151A (en) * | 2014-10-30 | 2015-02-25 | 北京宇航系统工程研究所 | Vacuum disturbance pilot flow field simulation method for rocket engine |
| US20170024496A1 (en) * | 2015-07-22 | 2017-01-26 | The Boeing Company | Methods and apparatus to model thermal mixing for prediction of multi-stream flows |
| WO2017084106A1 (en) * | 2015-11-20 | 2017-05-26 | 田川 | System and method for numerical simulation of aircraft flow field |
| CN108241303A (en) * | 2018-01-10 | 2018-07-03 | 北京航空航天大学 | A kind of Vacuum Plume effect Method for Accurate Calculation |
| CN110132606A (en) * | 2019-05-28 | 2019-08-16 | 北京航空航天大学 | Thruster plume parameter measurement system, method and device |
Non-Patent Citations (1)
| Title |
|---|
| YANG, Z 等: "Development of a coupled NS-DSMC method for the simulation of plume impingement effects of space thrusters", THERMOPHYSICS AND AEROMECHANICS, pages 835 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113340603A (en) * | 2021-03-22 | 2021-09-03 | 北京空间飞行器总体设计部 | System and method for testing vacuum plume force thermal effect of engine |
| CN113340603B (en) * | 2021-03-22 | 2022-09-27 | 北京空间飞行器总体设计部 | System and method for testing vacuum plume force thermal effect of engine |
| CN112699623A (en) * | 2021-03-24 | 2021-04-23 | 中国空气动力研究与发展中心计算空气动力研究所 | High-precision heat flow calculation method based on unstructured grid regularized reconstruction technology |
| CN112699623B (en) * | 2021-03-24 | 2021-05-25 | 中国空气动力研究与发展中心计算空气动力研究所 | High-precision heat flow calculation method based on unstructured grid regularized reconstruction technology |
| CN113657010A (en) * | 2021-10-21 | 2021-11-16 | 山东神力索具有限公司 | Meshing adjustment method and system for rigging model and electronic equipment |
| CN113987975A (en) * | 2021-11-12 | 2022-01-28 | 北京航空航天大学 | Plume process simulation method and device, electronic equipment and storage medium |
| CN115618171A (en) * | 2022-06-06 | 2023-01-17 | 北京理工大学 | Propellant combustion balance product solving method based on homotopy algorithm |
| CN115618171B (en) * | 2022-06-06 | 2023-10-24 | 北京理工大学 | Method for solving propellant combustion balance product based on homotopy algorithm |
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