摘要:
为获取超高速碰撞过程中弹丸的飞行姿态及碰撞所产生的碎片云特性,开展了多序列激光阴影成像技术研究。利用多光源空间分离、偏振分光、光束角放大和补偿滤光等技术解决了单色光带来的衍射和干涉噪声以及碰撞瞬间强烈的自发光干扰问题,并先后在碰撞靶上建立了2序列、4序列和8序列激光阴影成像系统。该系统可以获得最小间隔1μs、曝光时间10ns、像素1000万的多个不同时刻的超高速瞬态变化过程图像,并在超高速碰撞靶试验中得到应用,获得了2~7km/s 撞击速度时碎片云的多序列阴影图像,该序列图像清晰地描述了碎片云的轮廓发展变化过程。该技术以低成本的方式实现了超高速摄影机的功能,满足目前碰撞试验粒子的飞行姿态及碎片云显示需要,并可以应用于其它超高速瞬态过程测量及流场结构显示。
Abstract:
Multi sequences laser shadowgraph technique has been developed for getting the pill pose and the debris cloud in the hypervelocity impact experiment.Double,four,and eight se-quences laser shadowgraph systems have been set up successively on the hypervelocity impact range at the base of the technique of multi-light source divided in space,polarization decomposi-tion,light angle magnification and compensated filter,etc.The noise of diffraction and interfer-ence with homochromy light has been resolved by using the techniques.The systems can get many images at different time in the hypervelocity variety process.When the least interval is 1μs,the time of exposure is 10ns and the image pixel is ten million.The systems were also used in the impact experiments.The multi sequences laser shadow images have been gotten at differ-ent conditions with the impact velocity from 2km/s to 7km/s,which describe the outline chan-ging process of the debris cloud.This technique meets the need of showing the flight attitude of projectile and debris cloud at low cost,and can be used to measure in the field of other hyperve-locity process as well as show the flow structure.
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