排序方式: 共有47条查询结果,搜索用时 15 毫秒
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Plume aerodynamic effects of cushion engine in lunar landing 总被引:1,自引:0,他引:1
During the second period of China "Tanyue" Project, the explorer will softland on the moon. The cushion engines are used to decelerate the explorer and reduce the impact on the lunar ground. It is necessary to study its plume effects on the explorer component. The self-developed PWS (Plume WorkStation) software based on direct simulation Monte Carlo (DSMC) method is used to simulate the plume effects of two 150 N engines. Due to the complex structure of the explorer, PWS uses a decoupling method to treat the boundary mesh, which mainly interacts with simulation particles, and has no relation with the computational grids. After the analytical expressions of plane surfaces and curved surfaces of each boundary block are given, the particle position within or without the boundary blocks can be easily determined. Finally the 3D plume field of two 150 N engines is simulated. The pressure, temperature and velocity distributions of plume field are clearly presented by three characteristic slices. The aerodynamic effects on the explorer bottom, the landfall legs and antenna are separately shown. The compression influence on the plume flow of four landfall legs can be observed. 相似文献
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高温射流流场计算是尾焰辐射目标特性计算的前提,然而由于缺少可靠实验数据,针对湍流超声速射流的数值模拟多集中于低温射流,高温射流计算与实验的对比工作还很少见。利用k-ωSST双方程湍流模型,模拟了多个典型超声速射流实验的流场速度与温度分布,通过与实验结果进行对比,建立了一种超声速射流计算方法。首先,通过对比多个低温射流的实验与计算结果,探索了湍流模型中可压缩修正以及来流湍动粘性比对超声速射流计算结果的影响;进而,针对火箭发动机尾焰实验,计算尾焰流场与流场红外辐射,流场辐射计算结果与实验观测结果符合较好,进一步验证了计算方法。最终认为经过可压缩修正的k-ωSST双方程湍流模型结合湍动粘性比取值30可以作为超声射流计算中较为典型的湍流计算方法。 相似文献
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离子推力器羽流特性及其污染分析 总被引:2,自引:0,他引:2
介绍了与电推进系统有关的空间环境效应的形成原因及其对航天器性能、寿命等的影响。阐述了离子火箭发动机羽流内束离子、中性推进剂原子、交换电荷(CEX)离子和电子等主要成分与航天器相互作用的过程及机理。分析表明,离子推力器出口处的中性推进剂原子与高速束离子流碰撞后产生的CEX离子Xe^+,以及带电离子轰击推力器组件特别是加速极所产生的金属CEX离子,是造成离子火箭发动机羽流污染的主要成分。在此基础上提出了若干防污染措施。 相似文献