动态长度下压力交换器内脉动掺混研究

Dynamic Length Research on the Pulsating Mixing of Rotary Pressure Exchanger

建立压力能交换器的二维非稳态数值模型,研究了进流速度v、斯特劳哈尔数St以及脉动幅度A等对孔道内旋涡运动和掺混区形成的影响。结果表明,旋涡周期性脱落是掺混区形成的主要原因,涡强越大掺混越严重;St数的增大以及A的减小将使孔道内旋涡强度增强;St数的增大将使尺寸效应明显,掺混受涡强影响小,因而对于一定孔道存在最优的运行St数。并且随着A的增大,掺混区的稳定性变强,孔道的最优运行St数减小。

The rotary pressure exchanger has been simulated by a two-dimension unsteady numerical model.The effects of inlet velocity,Strouhal number and pulsating amplitude on the motion of vortex and mixing characteristic in the duct have been studied.The results show that the forming of mixing zone is mostly caused by the periodic vortex shedding.The vortex strength is stronger,the mixing is evident.The bigger Strouhal number and the small pulsating amplitude increase the vortex strength,while the rising of the Strouhal number enlarges the size effect,and the mixing is little influenced.There is an optimal Strouhal number for a constant rotor.Moreover,the larger the pulsating amplitude is,the more stability the mixing zone will be,so the optimal Strouhal number will decline.