Thermal Science 2024 OnLine-First Issue 00, Pages: 90-90
https://doi.org/10.2298/TSCI231127090Z
Full text ( 1466 KB)
Flow and heat transfer characteristics of high-pressure natural gas in the gaps of high-speed motors with a high radius ratio
Zhao Qiang (School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, China + Wolong Electric Nanyang Explosion Protection Group Co., LTD, Nanyang, China), yuanyichao@usst.edu.cn
Yuan Yichao (School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai, China)
A motor stator-gap-rotor model is established based on the numerical heat
transfer theory by using the finite volume method. The flow evolution of
high-pressure natural gas in the gap with a radius ratio of 0.971 is
investigated. The results demonstrate that the flow patterns of
high-pressure natural gas in the motor gap can be categorized into
turbulent, spiral Taylor-Couette, and turbulent Taylor-Couette flow; the
flow ranges are determined based on the Ta/Re2. Then, the flow and heat
transfer characteristics of the cooling medium in the gap under different
flow regimes as well as the mechanism of locally enhanced heat transfer in
the gap by the Taylor-Couette flow are explored. Finally, the mathematical
expressions for the Nusselt number of motor gap are determined in terms of
the Reynolds number, Taylor number, and Prandtl number by fitting using the
Levenberg-Marquardt and global optimization methods. Using these
expressions, the flow and heat transfer characteristics in the motor gap can
be predicted. Overall, this study provides useful and novel insights on the
design of cooling systems for high-speed motors.
Keywords: high radius ratio, high-pressure natural gas, Taylor-Couette flow, high-speed motor, numerical simulation