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

Response Tests on the Unsteady Fluid Forces for the Oscillating Centrifugal Impeller

摆动离心叶轮非定常流体力响应试验

基本信息

批准号：
06555055
负责人：
TSUJIMOTO Yoshinobu
金额：
$ 3.84万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

The first year was devoted to the estimation of the fluid force moment on the shroud of precessing impeller, from unsteady pressure measurements. It was shown that the destabilizing region increases as the increase is leakage flow rate, caused by the increase in the mean tangential velocity of the leakage flow. It was also found the increase of resistance at the outerradius causes the increase in the force measurements. A numerical analysis based on the bulk flow model was made. It was found that analysis can simulate most of important aspects experiments. It was also made clear that the leakage flow can be basically treated as a 2-D inviscid unsteady flow within variable clearance.In the 2nd year, direct force measurements on a whirling open-type compressor impeller which was designed and manufactured in the preceding year. To identify the phase relationship of the impeller rotation and the whirling motion, two triggering signals from the main shaft and the whirling sleeve was put in an AND circuit and a triggering signal was put out when the rotational and whirl signal were both on. The triggering signal was used to start accumulating the force signal in a FFT.An interesting result which suggests the possibility of both forward and backward whirl instability was obtained. However, a detailed inspection of the fluctuating force suggests the existence of unexpected shaft vibration. Hence we should continue the experiments to obtain more reliable data.

第一年主要是通过非定常压力测量来估计加工叶轮叶冠上的流体力力矩。结果表明，随着泄漏流平均切向速度的增大，泄漏流的不稳定区域也随之增大。还发现外半径处阻力的增加导致力测量值的增加。基于体积流模型进行了数值分析。结果表明，分析可以模拟实验的大部分重要方面。也表明泄漏流动基本上可以看作是变间隙的二维无粘非定常流。第二年，对前一年设计制造的旋转开式压缩机叶轮进行了直接力测量。为了识别叶轮旋转和旋转运动的相位关系，将主轴和旋转套筒的两个触发信号放入与电路中，在旋转和旋转信号同时打开时发出一个触发信号。触发信号用于在FFT中开始积累力信号。得到了一个有趣的结果，它提示了向前和向后旋转不稳定的可能性。然而，对波动力的详细检查表明存在意想不到的轴振动。因此，我们应该继续实验，以获得更可靠的数据。