起动射流出口形状对其推力特性影响研究
Effects of Exit Geometry on the Propulsive Characteristics of the Starting Jet
DOI: 10.12677/APP.2019.94024, PDF,   
作者: 王 鑫*, 高 磊：四川大学空天科学与工程学院，四川 成都
关键词: 起动；射流推力与冲量；直径比； Starting Jet； Thrust and Impulse； Diameter Ratio
摘要: 本文采用数值模拟方法研究起动射流推进器出口形状对其产生的推力与冲量的影响。将圆管和圆孔喷管入口直径与出口直径的比值Dr (定义Dr为直径比)作为变量，通过改变直径比的值来表征起动射流出口形状的差异。研究发现，在射流过程中，由于圆孔喷管出口形状对射流具有收缩作用，其出口一直有持续的过压效应发生，而圆管喷管只有在射流起始加速阶段会有较强的过压产生，因此圆孔喷管能向尾迹中产生更大的冲量Ih，并获得更大的推力FT。而且起动射流的冲量Ih及推进冲量FT随着直径比Dr的增大而增大，直到直径比达到临界值2.5时，Ih和FT几乎不再增长。
Abstract: The effect of the exit geometry of a vortex ring generator on the propulsive characteristics of the starting jet was studied numerically. For the orifice and tube nozzle configurations, the ratio of the nozzle entrance to exit diameters, dubbed as the diameter ratio Dr, was found to have significant effect on propulsive characteristics of the starting jet. The higher impulse generated by the orifice nozzle (Dr > 1) than that of the tube nozzle (Dr = 1) is attributed to the consistent over-pressure effect at the nozzle exit plane during the entire fluid ejection history, while the over-pressure effect only exist during the initial jet startup for the tube nozzle. The results show that the hydrodynamic impulse and net propulsive impulse of the starting jet increases against the diameter ratio until a critical value of around Dr = 2.5 is approached.
文章引用：王鑫, 高磊. 起动射流出口形状对其推力特性影响研究[J]. 应用物理, 2019, 9(4): 197-206. https://doi.org/10.12677/APP.2019.94024

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