Opto-mechanical design of optical window for aero-optics effect simulation instruments

A complete theory is established for opto-mechanical systems design of the window in this paper, which can make the design more rigorous. There are three steps about the design. First, the universal model of aerodynamic environment is established based on the theory of Computational Fluid Dynamics, and the pneumatic pressure distribution and temperature data of optical window surface is obtained when aircraft flies in 5-30km altitude. 0.5-3Ma speed and 0-30 degrees angle of attack. The temperature and pressure distribution values for the maximum constraint is selected as the initial value of external conditions on the optical window surface. Then, the optical window and mechanical structure are designed, which is also divided into two parts: First, according to the classical strength theory, the requirement of optical materials is proposed, and the optimal aspect ratio of window is designed. Second, according to the force of the window surface and the performance of the seal members, mechanical structure which meet requirements of the security and tightness is designed. Finally, rigorous analysis and evaluation are gived about the structure of optics and mechanics we have designed. There are two parts to be analyzed. First, the Fluid-Solid-Heat Coupled Model is gived based on finite element analysis. And the deformation of the glass and structure can be obtained by the model, which can assess the feasibility of the designed optical windows and ancillary structure; Second, the new optical surface is fitted by Zernike polynomials according to the deformation of the surface of the optical window, which can evaluate imaging quality impact of spectral camera by the deformation of window.