2 The 7th 2001 National Aeroelastic Academic Exchange Conference on the Static Aeroelasticity of Medium Aspect Ratio Aircraft Deng Lidong Wants Shenyang Aircraft Research Institute, Shenyang, 0035, the main rigid body of the aircraft with the aircraft design comprehensive analysis system 80 software Dynamic characteristics and elastic aerodynamic characteristics were calculated. 2Study on the static aeroelasticity of the medium aspect ratio aircraft in the 7th National Aeroelastic Academic Exchange Conference in 2001. Deng Lidong wanted the Shenyang Aircraft Research Institute, Shenyang, 0035. The system 80 software calculates some of the main rigid aerodynamic characteristics and elastic aerodynamic characteristics of the aircraft, and gives the elastic correction coefficients of several main aerodynamic characteristics and the longitudinal chordwise load distribution curves of some longitudinal typical cases. Finally, this paper compares the calculation results with the results obtained in the data, and makes a preliminary exploration for the progress of this work.
1 Introduction In order to improve the maneuverability and agility of aircraft, the first generation aircraft often use a medium aspect ratio wing. Due to the increase of the wing aspect ratio and the relative weakening of the structural rigidity, the static aeroelastic deformation of the aircraft is also increased, and the influence of the elastic deformation on the aerodynamic handling performance and the flight load is also increased. Therefore, the accurate and effective calculation of the aeroelastic characteristics of a medium aspect ratio aircraft plays an important role in the design of the aircraft.
2 Theory and method of static aeroelastic calculation 2.1 The aerodynamic influence matrix is ​​solved in the aerodynamic calculation using the linear differential equation 1 of the disturbance velocity.
The singularity superposition method is used to solve the numerical solution of the aerodynamic calculation. When calculating an airplane, use a series of thin faces to levy the aircraft. These faces are divided into the children's facets, and the fixed intensity is calculated on each bin to calculate the normal disturbance velocity of each bin at the control points of the remaining bins. These normal velocities constitute an aerodynamic influence. Matrix for static aeroelastic calculations.
2.2 Aircraft structure and static aeroelastic calculation The various components of the aircraft are simulated by a number of elastic surfaces. Each elastic surface is composed of isotropic anisotropic plates and curved torsion beams. The displacement is taken from the mid-arc surface of the elastic surface. The connection between the displacement elastic faces is accomplished by a group of discrete spring elements. The structural flexibility of the external force induced by the external force is calculated as follows: The generalized stiffness matrix called the aircraft structure 0 The generalized matrix illusion is used to transform the generalized coordinates (1) into actual physical coordinates.
The aircraft of any configuration calculated according to the influence coefficient method is divided into small blocks, and the discrete aerodynamic force acting at the center of gravity of the small block is connected to the angle of attack array through the following matrix relationship.
Here 9-speed pressure, 3 small block diagonal array, 4 dynamic influence coefficient matrix, small angle of attack array, aerodynamic matrix, the same reason we can get the relationship between external force and angular displacement here, external force array, structural elasticity The coefficient matrix, the angular displacement array caused by external force, will take into account the aerodynamic gravity inertial force acting on the aircraft, and can get the mass array here, the gravity acceleration 3 flight speed, the pitch angular velocity, the mass of the small block here, 17 Regardless of the structural angle of attack distribution array, the pressure coefficient distribution array is finally replaced by the combination of the linear equations 12 to obtain the pressure distribution on each lift surface of the elastic aircraft. Of course, the prerequisite is to The initial data distribution, such as local angle of attack and texture characteristics, is known as rigid. It can also be seen from Equation 12 that the right term of the equation can be used for a variety of combinations of local angle of attack distributions for plane motion. The solution of Equation 12 can also be a combination of these various, 0 plane motion solutions. About, 0 plane motion is divided into two types, symmetry and antisymmetry.
For the symmetry case, the main consideration is the angle of attack of the plane rigid body aircraft at the unit angle of attack; the angle of attack of the plane rigid body aircraft at the unit pitch angular velocity; the angle of attack distribution of the non-planar rigid body aircraft at zero angle of attack; The angle of attack distribution when the deformation is caused by the action; the angle of attack of the plane rigid body plane caused by the deflection of the control plane at zero angle of attack; for the antisymmetric situation, the main consideration is the angle of attack of the plane rigid body aircraft when the unit side slip angle is used When the unit is rolling angular velocity, the angle of attack of the plane rigid body aircraft is distributed; when the unit yaw rate is used, the angle of attack of the plane rigid body plane is controlled, and the angle of attack of the plane rigid body plane is determined when the plane is anti-symmetric. Under the basic angle of attack distribution, Equation 12 is solved, and the process is the same, but the attack angle distribution of the right side of the equation changes every time.
For the antisymmetric case, the process of solving Equation 12 is similar to the symmetry case, except that the aerodynamic influence coefficient becomes the aerodynamic influence coefficient matrix under the antisymmetric constraint condition, and the structural elasticity influence coefficient matrix is ​​also The structure elasticity under the full structure affects the coefficient matrix.
3 The establishment of the calculation model 3.1 The aerodynamic horizontal model According to the function of the software, the function of the software and the calculation of the aerodynamic calculation of a certain model, the following aerodynamic calculation model is established, 1 left. In order to consider the fuselage effect of a certain type of aircraft and the bending and torsion effect of the wing, the shape of the fuselage is given respectively. The structure of the 3.2 structure is based on the structure and quality characteristics of a certain model, and the following structural model is established.
4 Static aeroelastic calculation 4.1 Full-machine static aeroelastic calculation According to the aerodynamic characteristics of a certain type of aircraft and the data provided by the data, the aerodynamic characteristics of =0.42.2 and 0-15 km were calculated respectively. 3 The relationship between the slope of the lift line of the aircraft and the derivative of the pitching moment and the height are given. It can be seen from the above that the calculated variation between the aerodynamic characteristics and the elastic aerodynamic characteristics of the aircraft with the number and height is reasonable, reflecting the longitudinal basic characteristics of the aircraft.
4.2 Elastic load distribution After the calculation of the elastic aerodynamic force, the elastic load distribution of the aircraft can be calculated according to the aircraft's overload coefficient flight degree and M number. 4 respectively gives the comparison and analysis of the results of the shear bending moment along the machine 5. Through the calculation of the aeroelasticity of a certain model, in addition to the distribution of the chordwise load of the wing of the aircraft's elastic aerodynamic characteristic curve, this paper also gives The influence of the structural elasticity of the aircraft on the relationship between some main aerodynamic parameters and the speed pressure is obtained, and the edge is the ARGON calculation result. It can be seen from the comparison of the curves that the results of ARGON calculations and the data provided are basically the same in the change law. The focus of the subsonic aircraft moves backward with the increase of the speed pressure, and the speed of the supersonic aircraft follows the speed. The pressure increases and moves forward, but the ARGON calculation results are slightly smaller than the data results.
The distribution of the spanwise direction; 5 gives the distribution of the torque along the wing and the chordwise load distribution of each section of the wing. From the calculated load distribution curve law and numerical value, the results are reasonable.
The coefficient, on the right is the civil, 4 calculated elastic correction factor. It can be seen from the comparison of the curves, 艮, the calculation results and the results provided by the data are also relatively different in the change law. The elastic correction coefficient decreases with the increase of the rapid pressure at M1, and the elastic correction coefficient is 1>1. As the increase in velocity is greatly reduced, the calculated elastic correction factor of 0 is slightly smaller than the data result.
Through the ruler 0, the software performs preliminary calculation and analysis comparison on the static aeroelasticity of a certain aircraft. A preliminary understanding of the basic characteristics of static aeroelasticity of a certain aircraft with a medium aspect ratio wing is given. By comparing with the limited data, it can be seen that the law of the calculation result is quite reasonable, but the elastic correction coefficient is slightly smaller, and the structural model of the aircraft should be improved to facilitate more advanced research in the future.
instituteTsAGIf1985.1 Guan De, Aircraft Aeroelastic Mechanics Handbook, Aviation Industry Press, 1994.http://news.chinawj.com.cn Editor: (Hardware Business Network Information Center) http://news.chinawj.com.cn
1 Introduction In order to improve the maneuverability and agility of aircraft, the first generation aircraft often use a medium aspect ratio wing. Due to the increase of the wing aspect ratio and the relative weakening of the structural rigidity, the static aeroelastic deformation of the aircraft is also increased, and the influence of the elastic deformation on the aerodynamic handling performance and the flight load is also increased. Therefore, the accurate and effective calculation of the aeroelastic characteristics of a medium aspect ratio aircraft plays an important role in the design of the aircraft.
2 Theory and method of static aeroelastic calculation 2.1 The aerodynamic influence matrix is ​​solved in the aerodynamic calculation using the linear differential equation 1 of the disturbance velocity.
The singularity superposition method is used to solve the numerical solution of the aerodynamic calculation. When calculating an airplane, use a series of thin faces to levy the aircraft. These faces are divided into the children's facets, and the fixed intensity is calculated on each bin to calculate the normal disturbance velocity of each bin at the control points of the remaining bins. These normal velocities constitute an aerodynamic influence. Matrix for static aeroelastic calculations.
2.2 Aircraft structure and static aeroelastic calculation The various components of the aircraft are simulated by a number of elastic surfaces. Each elastic surface is composed of isotropic anisotropic plates and curved torsion beams. The displacement is taken from the mid-arc surface of the elastic surface. The connection between the displacement elastic faces is accomplished by a group of discrete spring elements. The structural flexibility of the external force induced by the external force is calculated as follows: The generalized stiffness matrix called the aircraft structure 0 The generalized matrix illusion is used to transform the generalized coordinates (1) into actual physical coordinates.
The aircraft of any configuration calculated according to the influence coefficient method is divided into small blocks, and the discrete aerodynamic force acting at the center of gravity of the small block is connected to the angle of attack array through the following matrix relationship.
Here 9-speed pressure, 3 small block diagonal array, 4 dynamic influence coefficient matrix, small angle of attack array, aerodynamic matrix, the same reason we can get the relationship between external force and angular displacement here, external force array, structural elasticity The coefficient matrix, the angular displacement array caused by external force, will take into account the aerodynamic gravity inertial force acting on the aircraft, and can get the mass array here, the gravity acceleration 3 flight speed, the pitch angular velocity, the mass of the small block here, 17 Regardless of the structural angle of attack distribution array, the pressure coefficient distribution array is finally replaced by the combination of the linear equations 12 to obtain the pressure distribution on each lift surface of the elastic aircraft. Of course, the prerequisite is to The initial data distribution, such as local angle of attack and texture characteristics, is known as rigid. It can also be seen from Equation 12 that the right term of the equation can be used for a variety of combinations of local angle of attack distributions for plane motion. The solution of Equation 12 can also be a combination of these various, 0 plane motion solutions. About, 0 plane motion is divided into two types, symmetry and antisymmetry.
For the symmetry case, the main consideration is the angle of attack of the plane rigid body aircraft at the unit angle of attack; the angle of attack of the plane rigid body aircraft at the unit pitch angular velocity; the angle of attack distribution of the non-planar rigid body aircraft at zero angle of attack; The angle of attack distribution when the deformation is caused by the action; the angle of attack of the plane rigid body plane caused by the deflection of the control plane at zero angle of attack; for the antisymmetric situation, the main consideration is the angle of attack of the plane rigid body aircraft when the unit side slip angle is used When the unit is rolling angular velocity, the angle of attack of the plane rigid body aircraft is distributed; when the unit yaw rate is used, the angle of attack of the plane rigid body plane is controlled, and the angle of attack of the plane rigid body plane is determined when the plane is anti-symmetric. Under the basic angle of attack distribution, Equation 12 is solved, and the process is the same, but the attack angle distribution of the right side of the equation changes every time.
For the antisymmetric case, the process of solving Equation 12 is similar to the symmetry case, except that the aerodynamic influence coefficient becomes the aerodynamic influence coefficient matrix under the antisymmetric constraint condition, and the structural elasticity influence coefficient matrix is ​​also The structure elasticity under the full structure affects the coefficient matrix.
3 The establishment of the calculation model 3.1 The aerodynamic horizontal model According to the function of the software, the function of the software and the calculation of the aerodynamic calculation of a certain model, the following aerodynamic calculation model is established, 1 left. In order to consider the fuselage effect of a certain type of aircraft and the bending and torsion effect of the wing, the shape of the fuselage is given respectively. The structure of the 3.2 structure is based on the structure and quality characteristics of a certain model, and the following structural model is established.
4 Static aeroelastic calculation 4.1 Full-machine static aeroelastic calculation According to the aerodynamic characteristics of a certain type of aircraft and the data provided by the data, the aerodynamic characteristics of =0.42.2 and 0-15 km were calculated respectively. 3 The relationship between the slope of the lift line of the aircraft and the derivative of the pitching moment and the height are given. It can be seen from the above that the calculated variation between the aerodynamic characteristics and the elastic aerodynamic characteristics of the aircraft with the number and height is reasonable, reflecting the longitudinal basic characteristics of the aircraft.
4.2 Elastic load distribution After the calculation of the elastic aerodynamic force, the elastic load distribution of the aircraft can be calculated according to the aircraft's overload coefficient flight degree and M number. 4 respectively gives the comparison and analysis of the results of the shear bending moment along the machine 5. Through the calculation of the aeroelasticity of a certain model, in addition to the distribution of the chordwise load of the wing of the aircraft's elastic aerodynamic characteristic curve, this paper also gives The influence of the structural elasticity of the aircraft on the relationship between some main aerodynamic parameters and the speed pressure is obtained, and the edge is the ARGON calculation result. It can be seen from the comparison of the curves that the results of ARGON calculations and the data provided are basically the same in the change law. The focus of the subsonic aircraft moves backward with the increase of the speed pressure, and the speed of the supersonic aircraft follows the speed. The pressure increases and moves forward, but the ARGON calculation results are slightly smaller than the data results.
The distribution of the spanwise direction; 5 gives the distribution of the torque along the wing and the chordwise load distribution of each section of the wing. From the calculated load distribution curve law and numerical value, the results are reasonable.
The coefficient, on the right is the civil, 4 calculated elastic correction factor. It can be seen from the comparison of the curves, 艮, the calculation results and the results provided by the data are also relatively different in the change law. The elastic correction coefficient decreases with the increase of the rapid pressure at M1, and the elastic correction coefficient is 1>1. As the increase in velocity is greatly reduced, the calculated elastic correction factor of 0 is slightly smaller than the data result.
Through the ruler 0, the software performs preliminary calculation and analysis comparison on the static aeroelasticity of a certain aircraft. A preliminary understanding of the basic characteristics of static aeroelasticity of a certain aircraft with a medium aspect ratio wing is given. By comparing with the limited data, it can be seen that the law of the calculation result is quite reasonable, but the elastic correction coefficient is slightly smaller, and the structural model of the aircraft should be improved to facilitate more advanced research in the future.
instituteTsAGIf1985.1 Guan De, Aircraft Aeroelastic Mechanics Handbook, Aviation Industry Press, 1994.http://news.chinawj.com.cn Editor: (Hardware Business Network Information Center) http://news.chinawj.com.cn
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