权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Experimental Study of Effects of Coriolis Force on Flow in a Rotating Deffuser

科里奥利力对旋转扩散器内流动影响的实验研究

基本信息

批准号：
04650164
负责人：
KOYAMA Hideharu
金额：
$ 1.22万
依托单位：
Tokyo denki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

To investigate the coupled effects of secondary flow, stability ( or instability ) due to Coriolis force, and adverse pressure gradient on the flow in a rotating diffuser of low aspect ratio, pressure, time-mean and fluctuating velocity components were measured. Conclusions reached as a result of present experimental study may be summarized as follows :(1) As increasing angular velocity, the boundary-layr development is promoted on the suction side and is suppressed on the pressure side due to thje secondary flows arising in the top and bottom wall boundary layrs. Eventually, the fully developed and retarded boundary layr separates only from the suction side wall due to the coupled effects of adverse pressure gradient, secondary flow and stability, while never separates from the pressure side due to the coupled effects of secondary flow and instability, but the secondary flow effect may be stronger than the instability effect,(2) Once the oncoming flow is separated from the suction side wall, the separated flow pattern is steady due to the combined effects of secondary flow and stability. The change ofg the angular velocity has little ro no effect on the mean velocity and turbulence intensity profiles at the diffuser mid-height. The flow is divided approximately into two regions, a through-flow ( jet ) on the pressure side and a separated flow ( wake ) on the suction side. The separated flow region with reverse flow is strabilized substantially,(3) In the shear flow region between the reverse flow and the through-flow, the turbulence intensity decreases with increasing the angular velocity at the same included angle because the production of turbulent shear stress is suppressed due to the stabilizing effect.

为了研究二次流、科氏力引起的稳定性（或不稳定性）和逆压梯度对小展弦比旋转扩压器内流动的耦合影响，测量了压力、时均速度和脉动速度分量。实验结果表明：（1）随着角速度的增加，在吸力面，由于在顶壁和底壁边界层中产生二次流，边界层的发展受到促进，而在压力面受到抑制。最终，由于逆压梯度、二次流和稳定性的耦合作用，充分发展和阻滞的边界层只与吸力面分离，而由于二次流和不稳定性的耦合作用，边界层始终不与压力面分离，但二次流的影响可能比不稳定性的影响更强。（2）来流一旦与吸力面分离，由于二次流和稳定性的共同作用，分离流态是稳定的。角速度的变化对扩散段中高处的平均速度和湍流度分布影响不大。流动大致分为两个区域，压力侧的通流（射流）和吸力侧的分离流（尾流）。（3）在反向流与通流之间的剪切流区，由于稳定作用抑制了湍流切应力的产生，在相同夹角下，湍流强度随角速度的增大而减小。