2相早后除极诱发时空湍流的抑制方法  

Effects of Blade Leading Edge Lean and Sweep on the Aerodynamic Performance of Centrifugal Impellers

作　　者：赵会晶[1] 王志恒[1] 唐永洪[1] 席光[1] 

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2015年第11期1-7,共7页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目（81271661，30870659）；教育部回国留学基金项目（第 40 批）

摘　　要：针对心肌细胞膜电位振荡的早期后除极（EAD）诱发的湍流,提出了恒定电场和周期电场两种湍流消除方法并对其效果进行了比较。基于LR91单细胞模型构建了一块包含400×400个细胞格点的二维组织,并通过将K＋电流门控变量时常数和Ca2＋电流最大电导分别增大4和2倍的方法在组织中心设置了一块由20×20个格点构成,具有EAD特征的区域。利用垂直场法诱导螺旋波斑图,并在EAD的作用下碎裂出现湍流即室颤。通过在反应扩散方程中引入电场项建立除颤模型,并引入膜电位的全局偏导数判别湍流的抑制效果。计算机仿真结果表明,恒定电场法抑制湍流的时间小于50 ms,周期场法需历时200 ms,但两种方法电场的实际作用时间无显著差异;尽管周期场法产生的总热能是恒定电场法的2.3倍,但周期场法一个周期产生的热能仅为恒定电场法的一半。因此,恒定电场法具有消除湍流快、总热能低的特点,但周期场法由于电场断续式的施加,更有利于减小热的持续积累对心肌的损伤。To study the effects of blade leading edge lean and sweep on the aerodynamic performance and stable operating range of centrifugal impellers, this paper presents four different blade leading edge lean and sweep by sweeping blade tip forward and backward, and sweeping blade root forward and backward along the meridional chord line. Firstly, the effects of blade leading edge sweep on the overall performance and flow field of a transonic centrifugal impeller are studied, and the results show that the blade tip forward sweep or blade root forward sweep can improve the highest isentropic efficiency and total pressure ratio of the centrifugal impeller; the blade tip backward sweep almost has no effect on the isentropic efficiency, but can decrease the total pressure ratio; the blade root backward sweep decreases both the isentropic efficiency and total pressure ratio. Additionally. the stall margin is increased by the blade tip forward sweep or blade root backward sweep, and reduced by the blade tip backward sweep or blade root forward sweep. Finally, the effect of blade leading edge sweep on a subsonic centrifugal impeller is investigated, and it indicates that, compared with transonic centrifugal impeller, the blade leading edge sweep has less effect on the isentropic efficiency and total pressure ratio in a subsonic centrifugal impeller. However, the effects on stall margin are almost the same for both transonic and subsonic centrifugal impellers. For an unshrouded transonic impeller, blade tip forward sweep is an effective way to increase its isentropic efficiency, pressure ratio and stall margin.

关 键 词：早期后除极 湍流波 除颤 电场 计算机仿真 

分 类 号：TK269[动力工程及工程热物理—动力机械及工程]