Aerodynamic Design and Numerical Investigation on Overall Performance of a Microradial Turbine With Millimeter-Scale
Aerodynamic Design and Numerical Investigation on Overall Performance of a Microradial Turbine With Millimeter-Scale
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DOI：
10.1115/1.3159375
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发表时间：
2010-03
影响因子：
1.5
通讯作者：
Lei Fu;Yan Shi;Qinghua Deng;Z. Feng
中科院分区：
文献类型：
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作者：
Lei Fu;Yan Shi;Qinghua Deng;Z. Feng
对于毫米级微型涡轮机，主要的挑战是实现一个设计方案，以满足气动热力学，几何约束，结构强度和组件功能的要求，同时考虑适用的材料，可实现的制造和安装技术。本文主要对一种直径为10 mm的毫米级径向涡轮机的气动热力设计、几何设计和总体性能预测进行了数值研究，设计了四种不同的涡轮机转子型线，并对它们进行了比较，以选择适合于微型径向涡轮机的型线。微型燃气轮机中的离开速度损失被发现是效率低下的一个很大来源。通过对转子叶片几何结构和扩压器型线的改进，降低了出口马赫数，提高了总静效率。与常规燃气轮机不同，微型燃气轮机在低雷诺数（10 4 ~ 10 5）下工作，对流动分离、传热以及层流到湍流的转捩有重要影响。基于选定的转子型线，研究了几种微气体涡轮机配置，这些配置具有0.1 mm、0.2 mm和0.3 mm的不同叶尖间隙、两种不同的等温壁条件和两种层流-湍流过渡模型，以了解低雷诺数的特殊影响。详细分析了这些因素对微燃气涡轮机整体性能的影响。结果表明，在毫米级微径向涡轮的设计过程中，这些配置应包括和重视。
For millimeter-scale microturbines, the principal challenge is to achieve a design scheme to meet the aerothermodynamics, geometry restriction, structural strength, and component functionality requirements while in consideration of the applicable materials, realizable manufacturing, and installation technology. This paper mainly presents numerical investigations on the aerothermodynamic design, geometrical design, and overall performance prediction of a millimeter-scale radial turbine with a rotor diameter of 10 mm. Four kinds of turbine rotor profiles were designed, and they were compared with one another in order to select the suitable profile for the microradial turbine. The leaving velocity loss in microgas turbines was found to be a large source of inefficiency. The approach of refining the geometric structure of rotor blades and the profile of diffuser were adopted to reduce the exit Mach number, thus improving the total-static efficiency. Different from general gas turbines, microgas turbines are operated in low Reynolds numbers (10 4 ―10 5 ), which has significant effect on flow separation, heat transfer, and laminar to turbulent flow transition. Based on the selected rotor profile, several microgas turbine configurations with different tip clearances of 0.1 mm, 0.2 mm, and 0.3 mm, two different isothermal wall conditions, and two laminar-turbulent transition models were investigated to understand the particular influences of low Reynolds numbers. These influences on the overall performance of the microgas turbine were analyzed in detail. The results indicate that these configurations should be included and emphasized during the design process of the millimeter-scale microradial turbines.