喷射器气体动力函数法的真实气体修正

Real Gas Correction on Gas Dynamics Function Method About Ejector

周三平 谷平

ZHOU Sanping GU Ping

西安石油大学机械工程学院, 陕西 西安 710065

Mechanical Engineering institute of Xi'an Shiyou University, Xi'an, Shaaxi 710065, China

索科洛夫提出的气体动力函数法是喷射器经典的设计方法，但是其基于理想气体的假设使得该方法应用于高压的真实气体时误差较大。运用气体热力学方法，从焓和定压比热容的定义入手，引入真实气体等熵温度绝热指数和等熵容积绝热指数，结合能量方程，推导出基于真实气体的气体动力学函数理论式。在此基础上，依据动量守恒和质量守恒定律，推导出了基于真实气体的气体喷射器与气力输送喷射器的基本方程。与索科洛夫设计方法进行了对比，结果表明，低压工况下，基于真实气体的修正方法与索科洛夫设计方法计算结果吻合，说明修正的设计方法覆盖了索科洛夫设计方法；但在高压工况下，两种设计方法的结果差异明显。基于真实气体的修正弥补了索科洛夫设计方法的局限，可适用于全压范围的喷射器设计。

The gas dynamic function method proposed by Sokolov is a classical method for designing injectors. However, its assumptions based on ideal gases make it error-prone when it is applied to real gases under high pressures. The gas thermodynamic method was used in this study. The real gas adiabatic indices at isentropic temperatures and isentropic volumes were introduced from the definitions of enthalpy and constant-pressure specific heat. Combined with the energy equations, the theoretical formula of the real gas dynamic function was derived. The basic equations of gas injectors and pneumatic delivery injectors based on real gases were then derived according to the laws of momentum conservation and mass conservation. A comparison with Sokolov's design method showed that, under the low-pressure working condition, the computational results obtained using the revised method based on real gases were consistent with results obtained with Sokolov's design method, indicating that the revised design method covered Sokolov's design method. However, under the high-pressure working condition, the results for these two design methods were significantly different. The real gas correction compensated for the limitations of Sokolov's design method and can be applied to injector design for the entire pressure range.

10.11885/j.issn.1674-5086.2017.09.28.01