基于有限单元法和计算流体动力学的光机热集成仿真分析研究

Simulation Analysis of Optical Machine Thermal Integration Via Finite Element Method and Computational Fluid Dynamics

使用计算流体动力学、传热学、固体弹性力学和光学的多物理场耦合集成仿真分析技术完成了红外热像仪中光机的热特性与热设计研究。采用有限单元法(Finite Element Method,FEM)和计算流体动力学(Computational Fluid Dynamics,CFD)得到了光机内部的温度场、应力变形分布及光学件面形。基于最小二乘法成功移除了光学元件的刚体位移,将刚体位移和移除刚体位移的标准Zernike系数作为设计输入条件导入光学系统中。对比在常温、自然散热和强对流不同条件下的弥散斑和传函曲线,实现了红外热像仪光机热集成及耦合仿真分析,该光机热集成仿真分析研究技术对光学系统结构设计和研究具有借鉴意义。

The thermal characteristics and thermal design of optical machine in infrared thermal imager are completed via multi-physics coupling simulation analysis technology of computational fluid dynamics,heat transfer,solid elasticity and optics.The optical mechanical temperature,stress distribution and the deformationdisplacement of the optical cell are obtained via finite element method and computational fluid dynamics.The rigid body displacement of optical cell is successfully removed by the least square method,the rigid body displacement and standard Zernike coefficient are introduced into the optical system.By comparing the spot diagram and MTF curve under different conditions of natural heat dissipation and strong convection heat dissipation,the optical mechanical thermal integration and coupling simulation analysis of infrared thermal imager are realized.The simulation results of optical mechanical thermal integration have important reference significance for the design and assembly of optical system.