喷头运动对水下气幕生成特性影响的研究

Study of Sprayer Movement Influence on Underwater Gas-Curtain Generation Characteristics

关键词:  水下推进  气幕生成特性  多股燃气射流  气液相互作用  数值模拟

Key words:  Underwater propulsion  Gas-curtain generation characteristics  Multi combustion gas jets  Gas-liquid interaction  Numerical simulation

摘要:

为了了解充液圆管内喷头运动过程中的气幕生成特性，采用高速摄像技术记录了喷头运动条件下多股燃气汇聚生成气幕过程。在实验基础上，建立了多股燃气射流在受限液体中扩展的三维非稳态数学模型，对实验工况进行了数值分析，气幕顶端扩展位移的计算值与实测值吻合较好。在此基础上，对比分析相同喷射条件下喷头运动与否对水下气幕生成特性的影响，结果表明:喷头运动，抑制了流场回流作用，增强了对气幕前端液体的推动作用，8ms时气幕运动速度由10m/s增大到11m/s；增大了喷头下游流场压力，8ms时运动喷头表面轴向受力增大了18%；降低了气幕顶部中心区域温度，但提高了壁面处温度。

Abstract:

To understand the gas-curtain generation characteristics in the liquid tube during sprayer moving process，the high speed video camera is applied to record the merging process of multi combustion gas jets with the motion of sprayer. On the base of experimental results，the three-dimensional unsteady mathematic model of the multi gas jets expansion process in the confined liquid medium is established，and simulation is conducted under the experimental condition. Simulated axial displacement of the gas-curtain is in a good agreement with experiment data. Contrastive analysis on the difference between moving sprayer and stationary sprayer is conducted under the same injection pressure，and effects of sprayer motion on generation of underwater gas-curtain are discussed. The numerical results indicate that with motion of sprayer，the backflow of the flow flied is restrained and push to liquid above the gas-curtain is enhanced，the expansion velocity of the gas-curtain increased from10m/s to 11m/s at 8ms. The pressure in downstream area of the sprayer increased and the axial force on the sprayer increased by 18% at 8ms. The temperature in the center area is decreased，but it is enhanced on the chamber wall.