陈琦, 谢昱飞, 袁先旭, 陈坚强. 头盔弹射出舱遭遇气流冲击过程的数值模拟研究[J]. 空气动力学学报, 2018, 36(5): 757-762. DOI: 10.7638/kqdlxxb-2016.0080
引用本文: 陈琦, 谢昱飞, 袁先旭, 陈坚强. 头盔弹射出舱遭遇气流冲击过程的数值模拟研究[J]. 空气动力学学报, 2018, 36(5): 757-762. DOI: 10.7638/kqdlxxb-2016.0080
CHEN Qi, XIE Yufei, YUAN Xianxu, CHEN Jianqiang. Numerical simulation on impact process of helmet in ejection test[J]. ACTA AERODYNAMICA SINICA, 2018, 36(5): 757-762. DOI: 10.7638/kqdlxxb-2016.0080
Citation: CHEN Qi, XIE Yufei, YUAN Xianxu, CHEN Jianqiang. Numerical simulation on impact process of helmet in ejection test[J]. ACTA AERODYNAMICA SINICA, 2018, 36(5): 757-762. DOI: 10.7638/kqdlxxb-2016.0080

头盔弹射出舱遭遇气流冲击过程的数值模拟研究

Numerical simulation on impact process of helmet in ejection test

  • 摘要: 某新型头盔在弹射出舱试验时,由于受气流冲击作用,外盔遭撕裂破坏。该头盔内外盔之间存在较大的空腔,初步分析认为,弹射出舱时,外部高速气流通过缝隙(护目镜与氧气面罩之间、泄流孔等)冲入空腔,将可能产生较大冲击载荷。针对此特点,采取的求解策略为,首先求解定常N-S方程,模拟缝隙打开前头盔的外部流场;然后求解非定常N-S方程,模拟打开缝隙后外部高速气流冲击内外盔空腔的非定常过程,从而近似模拟头盔弹射出舱过中遭遇气流吹袭的瞬态过程。同时研究了来流速度、弹射高度以及迎角等因素对头盔遭遇气流冲击的影响,分析了内外盔遭受的动态载荷。研究结果表明:在高速气流冲击下,该头盔外盔侧边缘的瞬间内外压差达到0.6个大气压,且分布不均,可能是造成其被撕裂的主要原因。

     

    Abstract: A new developed pilot helmet is destroyed in an ejection process in wind tunnel test. In this helmet, there is a big cavity between the outer helmet and the inner helmet. The initial analyses show that, when a high speed outer flow crushes into the cavity from the gap between the blinker and the oxygen mask, a great impact load may be induced on the helmet. For this characteristcs, a simulation method is proposed. First, the gap is closed, and the outer flow is simulated by solving the steady Navier-Stocks equations. Then, the gap is opened, the unsteady impact process of the outer flow crushed into the cavity is simulated by solving unsteady Navier-Stockes equations. The influence of free stream velocity, the flight altitude and the angle of attack on the impacting process is studied. The unsteady aerodynamic load on the inner helmet and the outer helmet are analyzed. The study shows that the difference between the pressure on the internal surface and that on the outside surface of the outer helmet is about 0.6atm under the impact of the air stream. The distribution of the pressure is asymmetrical in the impact process, which may lead to the dilacerations of the helmet.

     

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