CN106484980B - A kind of fixed rudder two dimension Correction Projectiles aerodynamic coefficient method - Google Patents
A kind of fixed rudder two dimension Correction Projectiles aerodynamic coefficient method Download PDFInfo
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Abstract
The invention discloses a kind of fixed rudder two dimension Correction Projectiles aerodynamic coefficient method, includes the steps that the physical model for constructing two-dimentional Correction Projectiles, establishing two dimension Correction Projectiles, establish two-dimentional Correction Projectiles grid model, two-dimentional Correction Projectiles grid model is imported to Fluent software, carrying out the setting of Fluent software and numerical value calculating；Aerodynamic coefficient is carried out using the present invention, accurate amendment can be quickly obtained and play aerodynamic parameter, it is not necessary to carry out wind tunnel test individually to verify the accuracy of Pneumatic Calculation data, a large amount of time and project funds can be saved；The present invention passes through wind tunnel test data verification, can guarantee the accuracy of calculated result.
Description
Technical Field
The invention belongs to the technical field of projectile simulation calculation, and relates to a pneumatic parameter calculation method of a fixed rudder two-dimensional trajectory correction projectile.
Background
In modern war, accurate strike has become the primary goal of battle, and the development of novel artillery guided munitions receives attention from all countries in the world. In the past, accurate striking is realized by means of missiles, but the missiles are expensive and poor in maintainability, and common shells cannot meet the aim of accurate striking, so that low-cost accurate striking is possible due to the generation of two-dimensional trajectory correction bullets. In order to balance the requirements of accurate striking and cost, a series of researches are carried out on two-dimensional trajectory correction bullets in various countries, and certain progress is made. Compared with a common system projectile, the fixed rudder two-dimensional trajectory correction projectile is refitted with a two-dimensional trajectory correction assembly. Compared with a common fuse, the two-dimensional trajectory correction assembly is additionally provided with modules such as trajectory measurement, flight control and execution mechanisms, the overall dimension is obviously changed, particularly the appearance, the mass center position and the like of a correction bullet are changed due to the existence of a fixed rudder, so that the pneumatic parameters of the whole bullet are changed, and the maximum range, flight stability, walking characteristics and the like of the correction bullet are influenced. For the aerodynamic shape of the fixed rudder two-dimensional trajectory correction projectile, domestic scholars have studied the structure aspects of the rudder piece installation position, the installation angle, different areas, different shapes and the like of the two-dimensional trajectory correction projectile, but do not analyze the aerodynamic calculation method of the correction projectile in detail. However, the change of the shape of the correction projectile makes the conventional pneumatic calculation method for the common system projectile unable to accurately describe the pneumatic characteristics of the correction projectile, so when the pneumatic characteristics of the correction projectile are studied, a set of pneumatic parameter value calculation method needs to be determined first.
Disclosure of Invention
The invention aims to solve the technical problem of providing a fixed rudder two-dimensional ballistic correction projectile pneumatic parameter calculation method which can accurately describe the pneumatic characteristics of the two-dimensional ballistic correction projectile.
The technical scheme adopted for solving the technical problems is as follows: a method for calculating aerodynamic parameters of a fixed rudder two-dimensional trajectory correction projectile comprises the following steps:
(1) replacing a fuze of the shot in the original system with a two-dimensional trajectory correction assembly by taking a certain type of shot as a prototype, so that the appearance of the exposed part of the two-dimensional trajectory correction assembly is consistent with the appearance of the fuze of the shot in the original system, and obtaining a two-dimensional trajectory correction shot; the two-dimensional trajectory correction bullet comprises a two-dimensional trajectory correction assembly arranged at the front end of the two-dimensional trajectory correction bullet and a bullet body arranged at the rear end of the two-dimensional trajectory correction bullet, and the two-dimensional trajectory correction assembly is in threaded connection with the bullet body and is fixed through a pin; a bullet belt is arranged on the bullet body;
the outer side of the two-dimensional ballistic trajectory correction assembly is fixedly provided with a first fixed rudder to a fourth fixed rudder, and the first fixed rudder to the fourth fixed rudder have the same structure, wherein the fourth fixed rudder is fixedly arranged on the right side of the two-dimensional ballistic trajectory correction assembly, the outer side surface of the fourth fixed rudder, which is opposite to the connecting surface of the fourth fixed rudder and the two-dimensional ballistic trajectory correction assembly, is a rhombic surface, the rhombic surface is parallel to the central axis of the two-dimensional ballistic trajectory correction assembly, the included angle between the connecting line of the front and rear end points of the rhombic surface and the central axis of the two-dimensional ballistic trajectory correction assembly is a rudder deflection angle α, the value range of the rudder deflection angle α is 3-6 degrees, the position of the first fixed rudder is obtained by rotating the fourth fixed rudder 90 degrees anticlockwise by taking the central axis of the two-dimensional ballistic trajectory correction assembly as an axis, the position of the third fixed rudder is obtained by rotating the fourth fixed rudder clockwise by 90 degrees by taking the central axis of the two-dimensional ballistic trajectory correction assembly as an axis, and the position of the;
(2) establishing a physical model of the two-dimensional ballistic trajectory correction bullet by utilizing SolidWorks software, wherein the size unit of the physical model is mm, the total length of the physical model is 930-940 mm, and the length of the two-dimensional ballistic trajectory correction assembly is 130-140 mm;
(3) carrying out grid division on the entity model by using ICEM software, and establishing a two-dimensional ballistic projectile grid model; in the process of establishing a two-dimensional trajectory correction bullet grid model, firstly generating an outer flow field and a surface grid, and then generating a body grid by the surface grid;
the surface grid is a grid generated on the surface of the two-dimensional ballistic correction bullet; the generation method of the surface mesh is based on a set surface method, and the mesh type of the surface mesh is a triangular mesh;
the maximum side length of the surface grid of the projectile body is 4.5-5.5 mm; the maximum side length of a surface grid of the two-dimensional trajectory correction assembly is 1.8-2.2 mm; the maximum side length of the surface grids of the elastic belt is 0.9-1.1 mm; the maximum side length of the surface grids from the first fixed rudder to the fourth fixed rudder is 0.35-0.45 mm; the maximum side length of the surface mesh of the external flow field is 250-350 mm;
the volumetric mesh is a mesh generated within the outer flow field; the volume grids are prism boundary layer grids; the first layer of grid height of the prismatic boundary layer grid is 0.9 multiplied by 10-5m～1.2×10-5m, the growth rate factor of the prism boundary layer grids is 1.15-1.35, and the number of boundary layers of the prism boundary layer grids is 4-10; the generation method of the projectile body grid is a rapid generation method, and the grid type of the projectile body grid is a tetrahedral mixed type;
the file format of the two-dimensional trajectory correction bullet grid model is mesh;
(4) the method comprises the steps that a two-dimensional ballistic correction bullet grid model with a mesh file format is led into Fluent software, the Fluent software converts the size unit of the led-in two-dimensional ballistic correction bullet grid model into m through a measurement instruction scale, the area of a surface grid and the volume of a body grid are checked through checking an instruction check, and whether the minimum area of a section grid is smaller than or equal to zero or not and whether the minimum volume of the body grid is smaller than or equal to zero or not are judged;
if the minimum area of the surface mesh is smaller than or equal to zero or the minimum volume of the body mesh is smaller than or equal to zero, carrying out mesh division on the entity model again until the minimum area of the surface mesh and the minimum volume of the body mesh are both larger than zero;
(5) and (3) carrying out Fluent software setting:
(5-1) selecting a three-dimensional implicit steady state solver based on density;
(5-2) defining boundary conditions
Selecting a boundary condition of an external flow field as a pressure far field, setting the air pressure in the external flow field to be 101200-101325 Pa, setting the temperature in the external flow field to be 280-300K, setting a fluid substance in the internal part of the external flow field as an ideal gas, and setting the boundary condition of the surface of a projectile body and the surface of a two-dimensional trajectory correction assembly as a non-slip wall surface;
(5-3) defining the turbulence model as an S-A turbulence model, wherein the S-A model equation is as follows:
wherein,representing a turbulent motion viscosity coefficient;
Cw1＝Cb1/κ2+(1+Cb2)/σv；
v is laminar flow viscosity coefficient and has the value range of 1.55 multiplied by 10-5～1.65×10-5；ujThe value of the turbulent flow viscosity coefficient is 1.75 multiplied by 10-5～1.85×10-5；fv1The viscosity damping coefficient is in a value range of 0-0.072; d is the distance from the surface of the projectile body to the wall surface, and the value range is 10-7～4m；Is represented by xjThe direction is differentiated by v;indicating viscosity of turbulent motionIntegral of coefficient over time;
parameters of the S-A turbulence model are:
σν＝0.65～0.69；
Cw2＝0.28～0.31；
Cw3＝1.90～2.05；
Cb2＝0.62～0.64；
κ＝0.4180～0.4190；
Cb1＝0.1350～0.1360；
(5-4) numerical calculation
In the numerical calculation process, the residual value range is 10-61 residual convergence criterion set to 10-5～10-3Setting the initial values of the convergence factors to be 0.1-0.8, and setting the Kerong number to be 1-5;
solving and calculating the S-A turbulence model to obtain the viscosity coefficient of the turbulence motionViscosity coefficient according to turbulent motionAnd calculating by using Fluent software to obtain the resistance coefficient, the lift coefficient and the rolling moment coefficient of the fixed rudder two-dimensional trajectory correction projectile.
In the method for calculating the aerodynamic parameters of the two-dimensional trajectory correction projectile of the fixed rudder, the parameters of the S-A turbulence model are respectively
σν＝2/3；
Cw2＝0.3；
Cw3＝2.0；
Cb1＝0.1355；
κ＝0.4187；
Cb2＝0.622。
In the method for calculating the aerodynamic parameter of the two-dimensional trajectory correction projectile with the fixed rudder, the rudder deflection angle α is 4 degrees.
The invention has the beneficial effects that: the pneumatic parameter calculation is carried out by utilizing the method, the more accurate pneumatic parameters of the correction bomb can be quickly obtained, the wind tunnel test is not needed to be independently carried out to verify the accuracy of the pneumatic calculation data, and a large amount of time and project expenses can be saved; the accuracy of the calculation result can be ensured through the verification of wind tunnel test data.
Drawings
Fig. 1 is a schematic diagram of an external structure of a two-dimensional ballistic projectile.
Figure 2 is a schematic diagram of the external structure of a two-dimensional ballistic modification assembly.
Fig. 3 is a schematic view of the rudder deflection angle α.
FIG. 4 shows the calculated drag coefficients for different grid size parameters.
Fig. 5 shows the calculated drag coefficients for different ay values.
Fig. 6 shows the calculated drag coefficients of different turbulence models.
Fig. 7 shows the lift coefficients calculated for different turbulence models.
In fig. 1-7, 1, two-dimensional trajectory modification assembly, 2, projectile, 3, bandolier, 1-1, first fixed rudder, 1-2, second fixed rudder, 1-3, third fixed rudder, 1-4, fourth fixed rudder, α, rudder deflection angle.
Detailed Description
The method comprises the steps of taking a certain system projectile as a prototype, replacing an original fuze of the prototype system projectile only with a two-dimensional ballistic correction assembly, replacing the fuze of an original system projectile with a two-dimensional ballistic correction assembly 1, enabling the basic appearance of an exposed part of the two-dimensional ballistic correction assembly to be kept consistent with the appearance of the original fuze to the maximum extent, and obtaining a two-dimensional ballistic correction projectile, wherein the two-dimensional ballistic correction projectile comprises the two-dimensional ballistic correction assembly 1 arranged at the front end of the two-dimensional ballistic correction projectile and a projectile body 2 arranged at the rear end of the two-dimensional ballistic correction projectile, the two-dimensional ballistic correction assembly 1 is in threaded connection with the projectile body 2 and is fixed through a pin, a projectile belt 3 is arranged on the projectile body 2, a first fixed rudder 1-4 to a fourth fixed rudder 1-4 are fixedly arranged on the outer side of the two-dimensional ballistic correction assembly 1, the first fixed rudder 1-4 is in structure, the same as the structure of the first fixed rudder 1-4, the fourth fixed rudder 1-4 is fixedly arranged on the right side of the two-dimensional ballistic correction assembly, a central axis fixed rudder 1-4, a central axis is fixedly connected with the two-dimensional ballistic correction assembly, a central axis fixed rudder 1-4 solid rudder, a central axis, the central axis of a central axis, the central axis is a central axis, the central axis of the central axis is a central axis, the central axis of the central axis, the central axis is a central axis, the central axis is a central axis, the central axis of the central axis, the central axis is fixedly connected with the central axis, the central axis is a central axis, the central axis is a central axis, the central.
The rudder pieces of the four fixed rudders are arranged around the missile body at a certain rudder deflection angle, one group of the four fixed rudders is differential rudders (a first fixed rudder 1-1 and a third fixed rudder 1-3), the other group of the four fixed rudders is equidirectional rudders (a second fixed rudder 1-2 and a fourth fixed rudder 1-4), the four fixed rudders are respectively connected with the two-dimensional correction missile body at a certain rudder deflection angle α, as shown in figure 2, the rudder deflection angles of the two differential rudders are the same, but the rudder deflection directions are different, so that the differential rudders can form steering torque to enable the correction assembly at the head to rotate relative to the missile body, and the rudder deflection angles and the rudder deflection directions of the two equidirectional rudders are the same, so that the equidirectional rudders can form control force and control torque.
1. And according to the established entity model, grid division software is applied to divide grids. The final determination of the mesh model requires the mesh size parameter and y+The values are studied, and the invention is based on setting different grid size parameters and y+And the grid model obtained by the value provides a basis for carrying out numerical calculation by using Fluent software and determining the grid model by comparing the calculation result.
In order to ensure the accuracy of grid generation and simultaneously consider the influence of the grid quantity on the calculation speed, size parameters need to be set for different parts of the two-dimensional ballistic projectile, and the required grid quantity is reduced while the accuracy is ensured. In order to determine the influence of the grid size parameters on the calculation result, different grid size parameters need to be compared and analyzed, and finally, reasonable parameters are determined. The different mesh model mesh size parameter settings are shown in table 1, defining mesh size parameters for three mesh models (model I, model II, model III). When the grid size parameter is set, the grid sizes of the two-dimensional trajectory correction component 1 and the fixed rudder sheet are set to be smaller so as to ensure the accuracy of a calculation result; the grid size of the external flow field is properly increased to ensure that the grid number is not excessive and avoid too long calculation time. In order to ensure the accuracy of the calculation result, prism boundary layer grids need to be generated, and the distance of the first layer grid is set to be 10-5And m, respectively defining the three grid models as a model I, a model II and a model III corresponding to different grid size parameters. As the size parameters of the outer flow field grids and the boundary layer parameters are set to be the same, the outer flow field grids and the boundary layer grids of the three grid models are basically consistent. When the grid size setting is adjusted, certain influence is generated on the grid number, and the grid number can be reduced by adjusting the grid growth rateAmount of the compound (A).
TABLE 1 mesh size parameter settings for different mesh models
Unit: mm is
2、y+Value setting
The projectile outlet speed is about 2.8Ma, the gas flow field around the projectile body is complex, the flow of the near-wall area on the surface of the projectile body can be divided into a viscous bottom layer, a transition layer and a logarithmic law layer, and the viscous bottom layer area of the near-wall area is usually divided into a distance dimensionless parameter y+Weighing:
in the formula: delta y is the distance from the first layer of grids to the wall surface; ρ is the gas density; u. ofjIs the turbulent viscosity coefficient;
τwis the wall shear stress.
In order to ensure the accuracy of the pneumatic data, the first-layer grid distance delta y needs to be calculated, so that the grid model can better simulate the flow of the near-wall region. The value of Δ y is dependent on y+The value is determined, and y+The value will affect the convergence and accuracy of the calculation, and to obtain a suitable value of Δ y, y will need to be corrected+Values were studied computationally. General opinion is y+Within 30-300, ideal calculation results and convergence rate can be obtained. The Mach number of the Viscous group Spacing calculator, namely the sticky Grid Spacing calculator issued by NASA can be obtained as 2.5+The Δ y values at 5, 50 and 300 are shown in Table 2. Setting the value of delta y to 10 according to the calculated value of delta y and considering the error of the viscous grid spacing calculator-4m、10-5m、10-6m, i.e. setting the first layer grid height to 10 each when generating a prism boundary layer-4m、10-5m、10-6And m, performing numerical calculation by using Fluent software, and comparing calculation results of different delta y values.
TABLE 2 NASA formula calculated y+In relation to Δ y
3. Pneumatic calculation result analysis
3.1 influence of the mesh model on the calculation results
When the grid size parameter is studied, Δ y is set to 10-5(ii) a For Δ y studies, model II dimensional parameters were used. And when the Fluent is used for calculation, an S-A turbulence model commonly used in the aviation field is adopted.
3.1.1 mesh size parameters influence the calculation results
The calculation results of the resistance coefficients obtained by setting the grid models with different grid size parameters are shown in fig. 4, the grid size parameters of the different grid models are shown in table 1, and the wind tunnel test data errors are shown in table 3. It can be seen from fig. 4 that the change rule of the resistance coefficients of the model I, the model II and the model III in the three grid models is substantially consistent with the wind tunnel test data, and the smaller the grid size setting, the smaller the difference from the wind tunnel test. As can be seen from Table 3, model I, model II and model III all have the largest errors at Mach number 0.8, with the largest error for model I being 22.97%, for model I being 10.81% and for model III being 7.23%. Comparing the calculation results of the three models, finding that the grid size parameters have great influence on the calculation accuracy, and because the sizes of the projectile body of the model I and the grid at the two-dimensional trajectory correction component are large, large errors occur, which indicates that the sparse grid can not well accord with the wind tunnel test result, and only can reveal the change rule of the pneumatic parameters; the difference between the calculation results of the model II and the model III is not great, which shows that when the grid size is smaller, the reduction of the grid size does not obviously improve the calculation precision, but rather increases the calculation time. Therefore, when setting the mesh size parameters, the calculation results and calculation times of the models II and III are comprehensively considered, and the mesh size parameters are set as shown in table 4.
TABLE 3 model resistance coefficient error for different grid size parameters
Note: the error results in the table are all in percent
TABLE 4 grid size parameters
3.1.2 value influence on the calculation results
Dividing a grid model by adopting the grid size parameters to research different y+The influence of the values on the calculation results is shown in fig. 5 for the resistance coefficient change curve, and in table 5 for the wind tunnel test data errors (the resistance coefficient errors calculated for different Δ y values). When Δ y is set to 10-4m、10-5m、10-6m is, corresponding to y+The maximum values are about 360, 70 and 5 respectively. The change rule of the resistance coefficient obtained by calculating each value of the delta y is basically consistent with that of a wind tunnel test, but different delta y values still have certain influence on the calculation result, and the delta y is 10-4m, the error of the calculated result is large, the maximum error is 18.95 percent, and the delta y is 10-5m、10-6And m, the calculation results are relatively close, the maximum error is within 10%, and the two delta y values can be applied to the pneumatic calculation of the two-dimensional ballistic correction projectile. However, a smaller value of Δ y increases the number of grids, resulting in an increase in calculation time, and to shorten the calculation time, Δ y is selected to be 10-5m。
TABLE 5 resistance coefficient error calculated for different Delay values
3.2 Effect of Fluent turbulence model on the calculation results
Setting Deltay to 10-5And m, generating a grid model by adopting the grid size parameters given in the table 4, and performing pneumatic calculation on the obtained grid model by utilizing Fluent software. The initial velocity of the correction projectile is about 2.8Ma, and the Reynolds number is 107And accordingly, selecting a three-dimensional implicit steady state solver based on density.
3.2.1 defining boundary conditions
Selecting a boundary condition of a computational domain flow field as a pressure far field, setting the air pressure as 101325Pa, setting the temperature as 300K, selecting ideal gas from a fluid substance, and setting an elastomer as a non-slip wall boundary condition.
3.2.2 defining a turbulence model
And selecting an S-A turbulence model and A Standard k-epsilon turbulence model (k-epsilon model for short) for comparison, wherein the parameters adopt default values. When the k-epsilon model is applied to numerical calculation, different wall functions are selected according to the delta y value, so that the calculation is accurate and reliable.
3.2.3 initialization and computation
Residual convergence criterion set to 10-4The initial values of the convergence factors are all set to be 0.1, the Kerong number is set to be 1, and the real-time adjustment is carried out according to the residual error change in the calculation process, so that the convergence process is fast and accurate.
3.2.4 analysis of the calculation results
And calculating the corrected missile grid model under different conditions in order to compare the influence of different turbulence models on the calculation result. The calculation conditions are as follows:
(1) the Mach numbers of the resistance coefficient analysis are set to be 0.8, 1.2, 1.5, 2.0 and 2.5, and the attack angle and the sideslip angle are both 0 degree;
(2) the lift coefficient analysis sets Mach number at 2.0, angles of attack at + -4 deg. + -2 deg. and 0 deg., and sideslip angle at 0 deg..
And comparing the pneumatic parameters obtained by calculating the two turbulence models with the wind tunnel test data, and analyzing the influence of the turbulence models on the calculation result and the calculation time.
The calculation results of the two turbulence models are shown in fig. 6 and 7, and the errors from the wind tunnel test data are shown in table 6 and table 7. As can be seen from fig. 6 and 7, and tables 6 and 7, the calculation results of the two turbulence models and the wind tunnel test error are within 10%, most of the calculation results are about 5%, and the change rule of the aerodynamic parameters conforms to the wind tunnel test, so that the two turbulence models can be used for aerodynamic numerical calculation. Considering that the k-epsilon model is A two-pass model and the S-A model is A one-pass model, the S-A model takes shorter time to calculate one state than the k-epsilon model, and therefore, the S-A model is used for performing the pneumatic numerical calculation later.
TABLE 6 resistance coefficient error calculated for different turbulence models
Note: the error results in the table are all in percent
TABLE 7 Lift coefficient error calculated from different turbulence models
Note: the error results in the table are all in percent
By analyzing different grid size parameters, y+The influence of the value and turbulence model on the calculation result is obtained：
(a) The grid size parameter has a large influence on the calculation accuracy, the smaller the grid size setting is, the smaller the difference with the wind tunnel test is, however, when the grid size parameter is set to be smaller, the reduction of the grid size does not obviously improve the calculation accuracy, but increases the calculation time;
(b)y+the value has larger influence on the calculation precision and the calculation time, and is reasonable+The value can reduce the calculation time while ensuring the calculation precision, and improve the calculation efficiency;
(c) the accuracy of the S-A model and the k-epsilon model in pneumatic calculation of the correction bomb is equivalent, but the S-A model is short in calculation time and small in required calculation resource.
(d) When the correction projectile is pneumatically calculated, the value of delta y is set to 10-5And m, setting the sizes of the grids at the projectile body and the correction assembly to be smaller, and calculating by adopting an S-A model.
The S-A model equation is:
wherein,representing a turbulent motion viscosity coefficient;
Cw1＝Cb1/κ2+(1+Cb2)/σv；
v is laminar flow viscosity coefficient and has the value range of 1.55 multiplied by 10-5～1.65×10-5；ujThe value of the turbulent flow viscosity coefficient is 1.75 multiplied by 10-5～1.85×10-5；fv1The viscosity damping coefficient is in a value range of 0-0.072; d is the distance from the surface of the projectile body to the wall surface, and the value range is 10-7～4m；Is represented by xjThe direction is differentiated by v;represents the integral of the viscosity coefficient of turbulent motion over time;
parameters of the S-A turbulence model are:
σν＝2/3；
Cw2＝0.3；
Cw3＝2.0；
Cb1＝0.1355；
κ＝0.4187；
Cb2＝0.622。
during the numerical calculation, the residual convergence criterion was set to 10-4The initial values of the convergence factors are all set to be 0.1, the count number (count number) is set to be 1, and the real-time adjustment is carried out according to the residual error change in the calculation process, so that the convergence process is fast and accurate.
Solving and calculating the S-A turbulence model to obtain the viscosity coefficient of the turbulence motionViscosity coefficient according to turbulent motionAnd obtaining the resistance coefficient, the lift coefficient and the roll moment coefficient of the fixed rudder two-dimensional trajectory correction projectile.
The above-described embodiments are merely preferred examples of the present invention and are not exhaustive of the possible embodiments of the present invention. Any obvious modifications to the above would be obvious to those of ordinary skill in the art, but would not bring the invention so modified beyond the spirit and scope of the present invention.
Claims (3)
1. A method for calculating aerodynamic parameters of a fixed rudder two-dimensional ballistic correction projectile is characterized by comprising the following steps:
(1) replacing a fuze of an original system projectile with a two-dimensional trajectory correction assembly (1) by taking a certain system projectile as a prototype, so that the appearance of the exposed part of the two-dimensional trajectory correction assembly is consistent with the appearance of the fuze of the original system projectile, and obtaining a two-dimensional trajectory correction projectile; the two-dimensional ballistic correction bullet comprises a two-dimensional ballistic correction assembly (1) arranged at the front end of the two-dimensional ballistic correction bullet and a bullet body (2) arranged at the rear end of the two-dimensional ballistic correction bullet, wherein the two-dimensional ballistic correction assembly (1) is in threaded connection with the bullet body (2) and is fixed through a pin; a bullet belt (3) is arranged on the bullet body (2);
the outer side of the two-dimensional ballistic correction assembly (1) is fixedly provided with a first fixed rudder (1-1) to a fourth fixed rudder (1-4), the structures of the first fixed rudder (1-1) to the fourth fixed rudder (1-4) are the same, the fourth fixed rudder (1-4) is fixedly arranged on the right side of the two-dimensional ballistic correction assembly, the outer side surface of the fourth fixed rudder (1-4), opposite to the connecting surface of the two-dimensional ballistic correction assembly (1), of the fourth fixed rudder (1-4) is a rhombic surface, the rhombic surface is parallel to the central axis of the two-dimensional ballistic correction assembly (1), the included angle between the connecting line of the front end point and the rear end point of the rhombic surface and the central axis of the two-dimensional ballistic correction assembly (1) is a rudder deflection angle α, the value range of the rudder deflection angle α is 3-6 degrees, the position of the first fixed rudder (1-1) is obtained by the fourth fixed rudder (1-4) rotating 90 degrees counterclockwise by taking the central axis of the two-dimensional correction assembly (1) as an axis, the position of the third fixed rudder (1-3) is obtained by the fourth fixed rudder (1-4) rotating clockwise by taking the central axis of the fourth fixed ballistic correction assembly (1-4) as a second fixed rudder (1-4) and the second fixed rudder (1-4) as a rudder axis;
(2) establishing a physical model of the two-dimensional ballistic trajectory correction bullet by utilizing SolidWorks software, wherein the size unit of the physical model is mm, the total length of the physical model is 930-940 mm, and the length of the two-dimensional ballistic trajectory correction assembly (1) is 130-140 mm;
(3) carrying out grid division on the entity model by using ICEM software, and establishing a two-dimensional ballistic projectile grid model; in the process of establishing a two-dimensional trajectory correction bullet grid model, firstly generating an outer flow field and a surface grid, and then generating a body grid by the surface grid;
the surface grid is a grid generated on the surface of the two-dimensional ballistic correction bullet; the generation method of the surface mesh is based on a set surface method, and the mesh type of the surface mesh is a triangular mesh;
the maximum side length of the surface mesh of the projectile body (2) is 4.5-5.5 mm; the maximum side length of a surface grid of the two-dimensional trajectory correction component (1) is 1.8-2.2 mm; the maximum side length of the surface grid of the elastic belt (3) is 0.9-1.1 mm; the maximum side length of the surface grids of the first fixed rudder (1-1) to the fourth fixed rudder (1-4) is 0.35-0.45 mm; the maximum side length of the surface mesh of the external flow field is 250-350 mm;
the volumetric mesh is a mesh generated within the outer flow field; the volume grids are prism boundary layer grids; the first layer of grid height of the prismatic boundary layer grid is 0.9 multiplied by 10-5m～1.2×10-5m, the growth rate factor of the prism boundary layer grids is 1.15-1.35, and the number of boundary layers of the prism boundary layer grids is 4-10; the generation method of the projectile body grid is a rapid generation method, and the grid type of the projectile body grid is a tetrahedral mixed type;
the file format of the two-dimensional trajectory correction bullet grid model is mesh;
(4) the method comprises the steps that a two-dimensional ballistic correction bullet grid model with a mesh file format is led into Fluent software, the Fluent software converts the size unit of the led-in two-dimensional ballistic correction bullet grid model into m through a measurement instruction scale, the area of a surface grid and the volume of a body grid are checked through checking an instruction check, and whether the minimum area of a section grid is smaller than or equal to zero or not and whether the minimum volume of the body grid is smaller than or equal to zero or not are judged;
if the minimum area of the surface mesh is smaller than or equal to zero or the minimum volume of the body mesh is smaller than or equal to zero, carrying out mesh division on the entity model again until the minimum area of the surface mesh and the minimum volume of the body mesh are both larger than zero;
(5) and (3) carrying out Fluent software setting:
(5-1) selecting a three-dimensional implicit steady state solver based on density;
(5-2) defining boundary conditions
Selecting a boundary condition of an external flow field as a pressure far field, setting the air pressure inside the external flow field to be 101200-101325 Pa, setting the temperature inside the external flow field to be 280-300K, setting a fluid substance inside the external flow field as an ideal gas, and setting the boundary condition of the surface of the projectile body (2) and the surface of the two-dimensional trajectory correction assembly (1) as a non-slip wall surface;
(5-3) defining the turbulence model as an S-A turbulence model, wherein the S-A model equation is as follows:
wherein,representing a turbulent motion viscosity coefficient;
Cw1＝Cb1/κ2+(1+Cb2)/σv；
v is laminar flow viscosity coefficient and has the value range of 1.55 multiplied by 10-5～1.65×10-5；ujThe value of the turbulent flow viscosity coefficient is 1.75 multiplied by 10-5～1.85×10-5；fv1The viscosity damping coefficient is in a value range of 0-0.072; d is the distance from the surface of the two-dimensional trajectory correction bullet to the wall surface, and the value range is 10-7～4m；Is represented by xjDirection pair vDifferentiation of；Represents the integral of the viscosity coefficient of turbulent motion over time;
parameters of the S-A turbulence model are:
σν＝0.65～0.69；
Cw2＝0.28～0.31；
Cw3＝1.90～2.05；
Cb2＝0.62～0.64；
κ＝0.4180～0.4190；
Cb1＝0.1350～0.1360；
(5-4) numerical calculation
In the numerical calculation process, the residual value range is 10-61 residual convergence criterion set to 10-5～10-3Setting the initial values of the convergence factors to be 0.1-0.8, and setting the Kerong number to be 1-5; solving and calculating the S-A turbulence model to obtain the viscosity coefficient of the turbulence motionViscosity coefficient according to turbulent motionAnd calculating by using Fluent software to obtain the resistance coefficient, the lift coefficient and the rolling moment coefficient of the fixed rudder two-dimensional trajectory correction projectile.
2. The method for calculating aerodynamic parameters of A fixed-rudder two-dimensional ballistic projectile according to claim 1, wherein the parameters of the S-A turbulence model are respectively:
σν＝2/3；
Cw2＝0.3；
Cw3＝2.0；
Cb1＝0.1355；
κ＝0.4187；
Cb2＝0.622。
3. the method of claim 2, wherein the rudder deflection angle α is 4 °.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102980583A (en) * | 2012-12-25 | 2013-03-20 | 哈尔滨工业大学 | Ballistic missile boosting section tracking method based on dimension-augmenting shifted Rayleigh filtering |
| CN102981797A (en) * | 2012-11-02 | 2013-03-20 | 中国航天科技集团公司第九研究院第七七一研究所 | Trigonometric function arithmetic device based on combination of feedback of coordinated rotation digital computer (CORDIC) algorithm and pipeline organization |
| CN103412493A (en) * | 2013-07-29 | 2013-11-27 | 北京航空航天大学 | Solid-liquid power cruising aircraft flight mission planning simulation system |
| CN103528587A (en) * | 2013-10-15 | 2014-01-22 | 西北工业大学 | Autonomous integrated navigation system |
| CN105550497A (en) * | 2015-12-04 | 2016-05-04 | 河海大学 | High-precision ballistic correction method |
-
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102981797A (en) * | 2012-11-02 | 2013-03-20 | 中国航天科技集团公司第九研究院第七七一研究所 | Trigonometric function arithmetic device based on combination of feedback of coordinated rotation digital computer (CORDIC) algorithm and pipeline organization |
| CN102980583A (en) * | 2012-12-25 | 2013-03-20 | 哈尔滨工业大学 | Ballistic missile boosting section tracking method based on dimension-augmenting shifted Rayleigh filtering |
| CN103412493A (en) * | 2013-07-29 | 2013-11-27 | 北京航空航天大学 | Solid-liquid power cruising aircraft flight mission planning simulation system |
| CN103528587A (en) * | 2013-10-15 | 2014-01-22 | 西北工业大学 | Autonomous integrated navigation system |
| CN105550497A (en) * | 2015-12-04 | 2016-05-04 | 河海大学 | High-precision ballistic correction method |
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