Numerical Study on the Effect of Unsteady Downstream Conditions on Hydrogen Gas Flow through a Critical Nozzle

• 作者: Heuy Dong Kim Junji Nagao Shigeru Matsuo Toshiaki Setoguchi
• 来源期刊: 流体动力学(英文)
• 学科: 物理学
• 关键词: COMPRESSIBLE FLOW CRITICAL NOZZLE Pressure Fluctuation Measurement SUPERSONIC FLOW
• 年，卷（期）: 2012,（4）
• 页码范围: 137-144
• 页数: 8页
• 分类号: O35

摘要

A critical nozzle (sonic nozzle) is used to measure the mass flow rate of gas. It is well known that the coefficient of discharge of the flow in the nozzle is a single function of Reynolds number. The purpose of the present study is to investigate the effect of unsteady downstream condition on hydrogen gas flow through a sonic nozzle, numerically. Navier-Stokes equations were solved numerically using 3rd-order MUSCL type TVD finite-difference scheme with a second-order fractional-step for time integration. A standard k-ε model was used as a turbulence model. The computational results showed that the discharge coefficients in case without pressure fluctuations were in good agreement with experimental results. Further, it was found that the pressure fluctuations tended to propagate upstream of nozzle throat with the decrease of Reynolds number and an increase of amplitude of pressure fluctuations.