Experiment Investigation of Proposed Design Concepts for a High Speed Mini Turbopump

高速微型涡轮泵拟议设计概念的实验研究

基本信息

批准号：
11650179
负责人：
NISHI Michihiro
金额：
$ 2.43万
依托单位：
KYUSHU INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650179/
关键词：
Fluid Machinery Turbopump Mini Pump Hydraulic Performance Design Concepts Impeller Performance Test Clearance ポンプ性能

项目摘要

Regarding those turbo-pumps of impeller diameter between several millimeter and 50 mm as mini size pumps, this research project aims to develop the hydrodynamic basis of a mini pump having high performance and applicability. To achieve the objective, we have studied the usefulness and effectiveness of the following proposed design-concepts experimentally and numerically :(1) Selection of higher driving speed of pump(2) Selection of semi-open type impeller (without front shroud)(3) Selection of greater number of blades and blade exit-angle(4) Selection of exit-to-inlet area ratio of impeller less than 1From two years' research work, the following major conclusions are obtained :1. It is clarified that a mini turbopump having the internal efficiency greater than 60 % is possible. It is noted that this value is greater than that shown in various textbooks.2. Experimental results indicate that the slip factor takes the value larger than 0.9 and the greater power input will be possible by u … More se of the present design concepts for mini pump.3. The similarity law is observed in the pump characteristics for a rotational speed greater than 4,000 rpm. This speed corresponds to the Reynolds number being 1.2 × 10^5, which almost agrees with the description shown in the literatures. Thus, a high speed pump is desirable for the mini size from the viewpoints of not only the Reynolds number effects but the reduction of loss fraction of mechanical seal.4. It is shown that the numerical turbulent flow analysis based on Reynolds Averaged Naiver Stokes equations with k-ω turbulence model will be reasonably applicable to study the hydraulic performance of mini impeller.5. The effect of axial clearance between the impeller tip and the casing wall on the hydraulic performance is satisfactorily predicted by the analysis.6. The bypass method to return some amount of flow from the exit of the pump to the suction pipe is usable to some extent to improve unstable Q-H curve in the low flow region.7. Though the present test results showed that the pump efficiency of closed impeller (with shroud) was better than that of semi-open impeller (without shroud), the further study is expected to explain them reasonably.8. It is confirmed from the present experimental and numerical study that the hydraulic performances including the axial clearance effect will be varied greatly depending on design methods, even if we selected the nearly identical specific speed and diameter. Less

针对叶轮直径在几毫米到50毫米之间的涡轮泵作为微型泵，本研究项目旨在开发具有高性能和适用性的微型泵的水动力基础，以实现这一目标，我们研究了其实用性和有效性。通过实验和数值分析提出以下设计理念：（1）选择较高的泵驱动转速（2）选择半开式叶轮（无前盖）（3）选择更多数量的叶轮叶片及叶片出口角(4)小于1的叶轮出口与入口面积比的选择经过两年的研究工作，得到以下主要结论： 1．明确了微型涡轮泵的内效率较高。超过60%是可能的。值得注意的是，这个值比各种教科书上显示的值都要大。2．实验结果表明，滑差系数取大于0.9的值，则可以得到更大的功率输入。 3. 转速大于 4,000 rpm 时，泵特性符合相似定律，该转速对应的雷诺数为 1.2 × 10^5，与图 1 中的描述基本一致。因此，从雷诺数效应和减少机械密封损失率的角度来看，高速泵是理想的选择。 4．采用k-ω湍流模型的平均Naiver Stokes方程可以合理地应用于研究微型叶轮的水力性能。5．通过分析，满意地预测了叶轮尖端与壳体壁之间的轴向间隙对水力性能的影响。6．采用从泵出口回流部分流量至吸入管的旁路方式，可在一定程度上改善低流量区不稳定的Q-H曲线。7．闭式叶轮（带护罩）的水力性能优于半开式叶轮（无护罩），期望进一步的研究能够合理地解释它们。8．从目前的实验和数值研究证实，包括轴向在内的水力性能。即使我们选择几乎相同的比速度和直径，间隙效果也会因设计方法的不同而有很大差异。