光学学报, 2018, 38 (10): 1001002, 网络出版: 2019-05-09
转塔气动光学效应时空特性 下载: 729次
Space-Time Characteristics of the Aero-Optical Effect Around Turrets
大气光学 气动光学效应 时空特性 数值模拟 平均流场效应 湍流效应 atmospheric optics aero-optical effect space-time character simulation mean flow effect turbulent effect
摘要
通过对相同马赫数、相近雷诺数、不同转塔口径(400 mm和2000 mm)的绕流流场模拟和气动光学效应进行分析,给出了不同发射方向时气动光学效应导致的光束倾斜角和光束质量因子的时间变化特性、统计特性以及时间相关特性。结果指出:多数场景下气动光学效应中平均流场效应占主要部分,平均流场效应的特征频率由绕流流场的特征频率决定。尺寸效应的研究表明:缩比实验可以有效模拟实际飞行状态下气动光学效应的统计特性,但无法准确模拟其时间相关特性。开展了前向发射时发射方向的优化选择,指出发射方向在中轴线上天顶角约为40°时,气动光学效应导致的波前畸变统计值和涨落值最小。分析了前向发射时发射口径的影响,指出发射光束半径增加会导致平均流场效应快速增加,但湍流效应基本不变。
Abstract
This study simulated the aero-optical effect of beams with different projection directions around turrets with different radii (400 mm and 2000 mm). The Mach number was fixed, and the Reynolds number remained similar in all cases. The space-time characteristic of the beam quality factor and beam tilt angle caused by the aero-optical effect was comprehensively studied. The aero-optical effect was mainly determined based on the mean flow effect, and the characteristic frequency of the mean flow effect was determined based on that of the flow around the turret. The spatial characteristic of the aero-optical effect was accurately reproduced in the reduced-scale experiments; however, the temporal characteristic was poorly simulated. The aero-optical effect appeared to be minimized at a projection direction of 40° zenith in the forward direction. An increase in the projection radius resulted in an increase in the mean flow effect while maintaining the turbulent effect almost constant.
董航, 徐明. 转塔气动光学效应时空特性[J]. 光学学报, 2018, 38(10): 1001002. Hang Dong, Ming Xu. Space-Time Characteristics of the Aero-Optical Effect Around Turrets[J]. Acta Optica Sinica, 2018, 38(10): 1001002.