为研究高压燃气射流在整装液体中的扩展规律,探索提高射流稳定性的控制方法,设计了4级渐扩型圆柱观察室.采用高速录像系统,观察了燃气射流在液体模拟工质中扩展与掺混的过程,获得了射流扩展形态的序列照片,测量了Taylor空腔的扩展速度,对比了观察室内壁形状对射流扩展过程的影响.建立了二维轴对称气液两相湍流模型,模拟射流扩展过程,计算得到的Taylor空腔扩展形态和扩展速度与实验吻合较好.研究结果表明,渐扩型观察室台阶处出现涡流,诱导射流径向扩展,可抑制Kelvin-Helmholtz不稳定效应,采用阶梯渐扩型边界有助于提高射流稳定性.%In order to investigate the expansion characteristics of the high pressure combustible gas jet in a bulk-loaded liquid and to explore the control methods for improveing the jet stability, a cylindrical four-stage stepped-wall chamber was designed. Using a high-speed kinescope system, the expansion and mixing process of the gas jet in the liquid was observed. A series of photos describing jet expansion form were obtained, the expansion velocity of the Taylor cavity was measured and the effects of the chamber wall shape on the jet expansion were compared. A 2-D axisymmetric gas-liquid two-phase turbulent flow model was developed to simulate the jet expansion process. The calculated jet expansion shape and expansion velocity of the Taylor cavity were consistent with experimental results. Obtained results show that vortex emerges at the chamber steps, which induces the jet to expand radially then restrains Kelvin-Helmholtz instability. The stepped-wall chamber boundary can improve the jet stability.
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