CIESC Journal ›› 2022, Vol. 73 ›› Issue (2): 622-633.DOI: 10.11949/0438-1157.20211135

• Fluid dynamics and transport phenomena • Previous Articles     Next Articles

Analysis of dynamic characteristics of flow field in impinging stream reactor based on step jet

Jianwei ZHANG(),Fengyuan AN,Xin DONG(),Ying FENG   

  1. Shenyang University of Chemical Technology, School of Mechanical and Power Engineering, Shenyang 110142, Liaoning, China
  • Received:2021-08-11 Revised:2021-12-06 Online:2022-02-18 Published:2022-02-05
  • Contact: Xin DONG

基于阶跃射流的撞击流反应器流场动态特性分析

张建伟(),安丰元,董鑫(),冯颖   

  1. 沈阳化工大学机械与动力工程学院,辽宁 沈阳 110142
  • 通讯作者: 董鑫
  • 作者简介:张建伟(1964—),男,博士,教授,zhangjianwei@syuct.edu.cn
  • 基金资助:
    国家自然科学基金项目(21476141);辽宁省兴辽英才计划项目(XLYC1808025);中央引导地方科技发展专项(2020JH6/10500051);辽宁省教育厅科学研究经费项目(LQ2020017)

Abstract:

The flow field characteristics of dynamic step impinging stream reactor were studied by experimental and numerical simulation methods, and the fluid flow law, turbulence characteristics and energy level under different inlet velocities were analyzed. The results show that under the condition of dynamic step inlet, the impact surface moved periodically between the two nozzles, and the flow parameters also changed periodically. The stagnation velocity was increased with the average inlet velocity. With the increase of the inlet velocity difference between the two nozzles, the moving speed of the impact surface was accelerated, and the fluid turbulence intensity in the impact zone was increased gradually. With the increase of the difference between the inlet average velocity and the inlet velocity, the average turbulent kinetic energy of XOZ plane in one cycle was gradually decreased. The flow field characteristics in dynamic impinging stream reactor and steady-state impinging stream reactor were compared to explore the influence of dynamic inlet conditions on the flow field characteristics of impinging stream reactor. The results show that the parameters of turbulent viscosity, turbulence intensity and turbulent kinetic energy of dynamic step impinging stream reactor were significantly higher than those of steady-state impinging stream reactor, and the gradient distribution of turbulent kinetic energy on the impact axis was greater than that of steady-state impinging stream reactor. Under the condition of dynamic inlet, the fluid turbulence in the impinging stream reactor was more intense and the energy level was higher, which was conducive to increasing the fluid disturbance and promoting mixing in the flow field.

Key words: impinging stream, dynamic control, numerical simulation, turbulent flow, experimental validation

摘要:

利用实验与数值模拟方法对动态阶跃型撞击流反应器流场特性进行研究,分析不同入口速度条件下流体流动规律、湍流特性以及能量水平。结果表明,动态阶跃型入口条件下,撞击面在两喷嘴之间周期性移动,流动参数也会发生周期性变化。随着入口平均速率的增大,驻点速度逐渐增大;随着两喷嘴入口速率差的增加,撞击面移动速度加快,撞击区流体湍流强度逐渐增加;随着入口平均速率与入口速率差的增大,XOZ平面在一个周期内的平均湍动能逐渐减小。对比动态撞击流反应器与稳态撞击流反应器内流场特性,探究动态入口条件对撞击流反应器流场特性的影响。结果表明,动态阶跃撞击流反应器湍流黏度、湍流强度和湍动能等参数均明显高于稳态撞击流反应器,撞击轴线上的湍动能梯度分布大于稳态撞击流反应器。动态入口条件下撞击流反应器流体湍动更剧烈,能量水平更高,有利于增加流场内流体扰动与促进混合。

关键词: 撞击流, 动态调节, 数值模拟, 湍流, 实验验证

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