Analysis Of Aerodynamic Effect Of Airborne Laser Communication System

When a surface-to-air missile flies supersonic,the atmospheric gases around it will flow at a high speed on the surface of the shell of the missile body,thus generating the aerodynamic flow field.This aerodynamic flow field has a serious impact on the working quality of laser communication system during laser guidance.For example,optical path difference and wave aberration may be caused in the process of light transmission,and misjudgment of received information or even short time communication interruption may be caused in the process of signal reception.These phenomena are collectively referred to as aero-optical effects.Therefore,it is of great strategic significance to study the aerodynamic optical effects of the laser communication system in the field of laser communication guidance.This dissertation mainly studies the new laser guidance mode,namely the ground-to-air missile under the mode of multi-aperture launch and diversity reception.When flying at different altitudes and speeds,the influence of aerodynamic flow field on the working quality of laser communication system can also be called the analysis of aerodynamic optical effect.First,according to the actual size and working mode of the surface-to-air missile,the missile body was geometrically modeled with Solid Works,and then the geometric model was imported into Fluent fluid analysis software,and the model was meshed with the Mesh software.A non-uniformly distributed turbulence model is selected for adaptation,and relevant parameters and material properties such as solver are set in detail,so as to obtain the density field distribution of the aerodynamic flow field around the laser communication system.Then the density field is converted to refractive index field by combining ray tracing with physical optics,moreover,optical correlation calculation was carried out to calculate the point diffusion function(PSF),Steller-ratio(SR),speckle radius containing 80% energy,MTF and other optical image quality evaluation functions.Finally,after repeated changes in flight altitude,flight speed and working wavelength,the numerical values of the optical image quality evaluation function of surface-to-air missile in different atmospheric environments are obtained.Range of flight altitude is 0 ? 20 km and the interval is 5km.Flying at Mach 3 and Mach 5;The operating wavelength range is 400 nm to 1550 nm.In this dissertation,the fluid dynamics simulation of the aerodynamic flow field around the laser communication system is carried out by using the Fluent finite element simulation software.The aerodynamic optical effect of the new laser guidance technology is analyzed and the conclusion is drawn.The experimental results show that with the increasing of flight altitude and the decreasing of flight speed,the influence of aerodynamic optical effect is gradually weakened,and the working state of the laser communication system is also gradually excellent.The longer the operating wavelength,the less the influence of aerodynamic optical effect.