Abstract
In this study, the results of NREL’s continued work on experimental characterization of the thermal performance of free-surface jets of automatic transmission fluid impinged on a heated target surface are presented. The measured heat transfer coefficients are useful for understanding factors influencing performance of driveline fluid-based cooling systems for electric machines and help designers in developing high-performance, power-dense and reliable machines. Experiments were carried out for different fluid and target surface temperatures (50°C, 70°C, and 90°C for the fluid and 90°C, 100°C, 110°C, and 120°C for the target surface). Impinging jet velocities (0.5 m/s to 7.5 m/s) and the jet position on the target surface (center versus edge) were also varied. The impinging angle was kept at 90° relative to the target surface. It was found that higher target surface temperature increased heat transfer coefficients, namely, increasing surface temperature from 90°C to 120°C enhanced heat transfer coefficient values at higher impinged jet velocities (7.5 m/s) by up to 15%.
Original language | American English |
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Number of pages | 7 |
DOIs | |
State | Published - 2019 |
Event | ASME 2019 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2019 - Anaheim, United States Duration: 7 Oct 2019 → 9 Oct 2019 |
Conference
Conference | ASME 2019 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2019 |
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Country/Territory | United States |
City | Anaheim |
Period | 7/10/19 → 9/10/19 |
Bibliographical note
See NREL/CP-5400-74284 for preprintNREL Publication Number
- NREL/CP-5400-76106
Keywords
- Automatic transmission fluid
- Electric machines
- Electric motors
- Jet impingement
- Thermal management