Aero-optical effect around turrets in high speed regime
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摘要: 针对高速流场下凸台周围的气动光学效应，对不同马赫数下的三种凸台形状周围的流场进行仿真计算，计算得到流场的密度变化，计算了光线经流场传输后的光程差。仿真结果表明：随马赫数增大，光程差逐步增大；同等条件下，不同出射角度对应的光程差不同，凸台存在强烈的尾流区域，从而导致较大的光程差；在马赫数达到跨音速时，凸台顶端也会产生较大的光程差；曲率较小的凸台结构对周围流场的影响较小。Abstract: This study simulated the aero-optical effect around the turret at different Mach numbers for three turret designs, calculated the density distribution of the flow field and the optical path difference after transmission in the flow field. The optical path difference increases with the increase of Mach number. The optical distortion over the turret field-of-regard is dependent on the beam direction, and there is large optical distortion in wake area. When the speed reaches transonic, the top of the turret will also produce large optical distortion. For different turret designs, the smaller the curvature, the smaller the aero-optical effect.
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Key words:
- aero-optics /
- computational fluid dynamics /
- simulation /
- optics window /
- density /
- optical path difference
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图 3 不同飞行速度下3种凸台形状周围流场的密度场分布（y=0剖面）
Figure 3. Contours of density in a cutting plane where y=0 at different flight speed
图 4 不同飞行速度下3种凸台形状周围流场的密度场分布（z=0.1875 m剖面）
Figure 4. Contours of density in a cutting plane where z=0.1875 m at different flight speed
图 5 光束出射方向示意图，其中AZ为转角，EL为仰角
Figure 5. Definition of beam viewing, where AZ is the azimuthal angle, EL is the elevation angle
图 6 飞行速度为0.4Ma时，光程差分布示意图
Figure 6. Contours of optical path differences (OPDs) in the entire field of view at a flight speed of 0.4Ma
图 7 飞行速度为0.8Ma时，光程差分布示意图
Figure 7. Contours of OPDs in the entire field of view at a flight speed of 0.8Ma
图 8 飞行速度为1.5Ma时，光程差分布示意图
Figure 8. Contours of OPDs in the entire field of view at a flight speed of 1.5Ma
图 9 出射角度为中轴线上45°时，光程差计算结果（turret Ⅱ，0.4Ma）
Figure 9. OPDs at beam direction of 45° (turret Ⅱ, 0.4Ma)
表 1 不同飞行速度下的光程差(turret Ⅱ，出射角度为中轴线上45°)
Table 1. OPDs at different flight speed (turret Ⅱ, AZ: 0°, EL: 45°)
Ma OPD(minimum)/
μmOPD(maximum)/
μmOPD(average)/
μm0.4 0.123 0.843 0.472 0.8 1.573 4.406 3.011 1.5 23.560 26.606 25.345 
下载: 导出CSV
表 2 不同凸台形状下的光程差(出射角度为中轴线上45°，飞行速度为0.8Ma)
Table 2. OPDs of different turret shapes (AZ: 0°, EL: 45°, 0.8Ma)
turret
shapeOPD(minimum)/
μmOPD(maximum)/
μmOPD(average)/
μmturret Ⅰ 1.9320 4.6160 3.2908 turret Ⅱ 1.5729 4.4058 3.0110 turret Ⅲ 1.1186 4.1705 2.7100
下载: 导出CSV
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