Parameter study for oil spray cooling on endwindings of electric machines via Eulerian–Lagrangian simulation

Zhao, An; Duwig, Christophe; Liu, Chuan; Gerada, David; Leksell, Mats

Abstract

The demand for larger power density and torque for the power traction motors used in electrified transportation puts forward a requirement for better thermal management methods. Spray cooling is a promising direct liquid cooling technique that has been proved to possess high heat removal capability in previous research. This paper investigates the heat transfer characteristics of spray cooling on endwindings of electric machines via numerical simulation through an Eulerian–Lagrangian approach. The utilized numerical models and calculated results are validated with experimentally measured data. The influence of different parameters and options involved in the simulation settings on the final results, like the stream numbers for the spray injector, the constant heat flux versus constant temperature thermal boundary condition, the influence of splashing, the effect of heat conduction in the endwindings and the Saffman lift force, only solving the energy equation for the air after its flow field reaches a steady-state, are evaluated. Parameter analyses are also conducted for operation conditions, configuration of the spray nozzles, and material properties of the coolant liquid. It is found that larger flow rate, smaller droplet size, lower spray height, more nozzle numbers, larger thermal conductivity and smaller viscosity of the coolant liquid tend to increase the overall heat transfer performance.

Citation

Zhao, A., Duwig, C., Liu, C., Gerada, D., & Leksell, M. (2023). Parameter study for oil spray cooling on endwindings of electric machines via Eulerian–Lagrangian simulation. Applied Thermal Engineering, 235, Article 121281. https://doi.org/10.1016/j.applthermaleng.2023.121281

• Journal Article Type: Article
• Acceptance Date: Aug 2, 2023
• Online Publication Date: Aug 18, 2023
• Publication Date: Nov 25, 2023
• Deposit Date: Nov 26, 2024
• Publicly Available Date: Nov 26, 2024
• Journal: Applied Thermal Engineering
• Print ISSN: 1359-4311
• Electronic ISSN: 1873-5606
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 235
• Article Number: 121281
• DOI: https://doi.org/10.1016/j.applthermaleng.2023.121281
• Keywords: Industrial and Manufacturing Engineering; Energy Engineering and Power Technology; Fluid Flow and Transfer Processes; Mechanical Engineering
• Public URL: https://nottingham-repository.worktribe.com/output/24864195
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S1359431123013108