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.
Original language | English |
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Article number | 121281 |
Journal | Applied Thermal Engineering |
Volume | 235 |
DOIs | |
Publication status | Published - 25 Nov 2023 |
Keywords
- CFD simulation
- DPM
- Electric machines
- Endwindings
- Multi-nozzles
- Spray cooling
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Mechanical Engineering
- Fluid Flow and Transfer Processes
- Industrial and Manufacturing Engineering