CFD simulations of electric motor end ring cooling for improved thermal management
Proper thermal management of an electric motor for vehicle applications extends its operating range. One cooling approach is to impinge Automatic Transmission Fluid (ATF) onto the rotor end ring. Increased ATF coverage correlates to enhanced heat transfer. Computational Fluid Dynamics (CFD) analytic...
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EDP Sciences
2022-01-01
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Series: | Science and Technology for Energy Transition |
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Online Access: | https://www.stet-review.org/articles/stet/full_html/2022/01/stet210308/stet210308.html |
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author | Grover Ronald O. Yang Xiaofeng Parrish Scott Nocivelli Lorenzo Asztalos Katherine J. Som Sibendu Li Yanheng Burns Cooper Van Gilder John Attal Nitesh Avanessian Oshin |
author_facet | Grover Ronald O. Yang Xiaofeng Parrish Scott Nocivelli Lorenzo Asztalos Katherine J. Som Sibendu Li Yanheng Burns Cooper Van Gilder John Attal Nitesh Avanessian Oshin |
author_sort | Grover Ronald O. |
collection | DOAJ |
description | Proper thermal management of an electric motor for vehicle applications extends its operating range. One cooling approach is to impinge Automatic Transmission Fluid (ATF) onto the rotor end ring. Increased ATF coverage correlates to enhanced heat transfer. Computational Fluid Dynamics (CFD) analytical tools provide a mechanism to assess motor thermal management prior to hardware fabrication. The complexity of the fluid flow (e.g., jet atomization, interface tracking, wall impingement) and heat transfer makes these simulations challenging. Computational costs are high when solving these flows on high-speed rotating meshes. Typically, a Volume-of Fluid (VOF) technique (i.e., two-fluid system) is used to resolve ATF dynamics within this rotating framework. Suitable numerical resolution of the relevant physics for thin films under strong inertial forces at high rotor speeds is computationally expensive, further increasing the run times. In this work, a numerical study of rotor-ring cooling by ATF is presented using a patent automated Cartesian cut-cell based method coupled with Automatic Mesh Refinement (AMR). This approach automatically creates the Cartesian mesh on-the-fly and can effectively handle complex rotating geometries by adaptively refining the mesh based on local gradients in the flow field which results in better resolution of the air-ATF interface. A Single non-inertial Reference Frame (SRF) approach is used to account for the rotating geometry and to further improve the overall computational efficiency. Quasi-steady state conditions are targeted in the analysis of the results. Important physics such as ATF jet structure, velocity detail near the air-jet interface, ATF coverage/accumulation on the ring surface, and cooling capacity are presented for a low-resolution Reynolds averaged Navier-Stokes (RANS), high-resolution RANS, and high-resolution Large-Eddy Simulation (LES) models. Computations are scaled over hundreds of cores on a supercomputer to maximize turnaround time. Each numerical approach is shown to capture the general trajectory of the oil jet prior to surface impingement. The high-resolution LES simulation, however, is superior in capturing small scale details and heat transfer between the free jet and surrounding air. |
first_indexed | 2024-04-12T03:17:40Z |
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id | doaj.art-78bfd7d5d6f647498c7b5ca8d8c97ed0 |
institution | Directory Open Access Journal |
issn | 2804-7699 |
language | English |
last_indexed | 2024-04-12T03:17:40Z |
publishDate | 2022-01-01 |
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series | Science and Technology for Energy Transition |
spelling | doaj.art-78bfd7d5d6f647498c7b5ca8d8c97ed02022-12-22T03:50:03ZengEDP SciencesScience and Technology for Energy Transition2804-76992022-01-01771710.2516/stet/2022015stet210308CFD simulations of electric motor end ring cooling for improved thermal managementGrover Ronald O.0Yang Xiaofeng1Parrish Scott2Nocivelli Lorenzo3Asztalos Katherine J.4https://orcid.org/0000-0003-4001-168XSom Sibendu5Li Yanheng6https://orcid.org/0000-0002-2954-1375Burns Cooper7Van Gilder John8Attal Nitesh9Avanessian Oshin10General Motors CompanyGeneral Motors CompanyGeneral Motors CompanyArgonne National LaboratoryArgonne National LaboratoryArgonne National LaboratoryConvergent Science Inc.Convergent Science Inc.Convergent Science Inc.Convergent Science Inc.Convergent Science Inc.Proper thermal management of an electric motor for vehicle applications extends its operating range. One cooling approach is to impinge Automatic Transmission Fluid (ATF) onto the rotor end ring. Increased ATF coverage correlates to enhanced heat transfer. Computational Fluid Dynamics (CFD) analytical tools provide a mechanism to assess motor thermal management prior to hardware fabrication. The complexity of the fluid flow (e.g., jet atomization, interface tracking, wall impingement) and heat transfer makes these simulations challenging. Computational costs are high when solving these flows on high-speed rotating meshes. Typically, a Volume-of Fluid (VOF) technique (i.e., two-fluid system) is used to resolve ATF dynamics within this rotating framework. Suitable numerical resolution of the relevant physics for thin films under strong inertial forces at high rotor speeds is computationally expensive, further increasing the run times. In this work, a numerical study of rotor-ring cooling by ATF is presented using a patent automated Cartesian cut-cell based method coupled with Automatic Mesh Refinement (AMR). This approach automatically creates the Cartesian mesh on-the-fly and can effectively handle complex rotating geometries by adaptively refining the mesh based on local gradients in the flow field which results in better resolution of the air-ATF interface. A Single non-inertial Reference Frame (SRF) approach is used to account for the rotating geometry and to further improve the overall computational efficiency. Quasi-steady state conditions are targeted in the analysis of the results. Important physics such as ATF jet structure, velocity detail near the air-jet interface, ATF coverage/accumulation on the ring surface, and cooling capacity are presented for a low-resolution Reynolds averaged Navier-Stokes (RANS), high-resolution RANS, and high-resolution Large-Eddy Simulation (LES) models. Computations are scaled over hundreds of cores on a supercomputer to maximize turnaround time. Each numerical approach is shown to capture the general trajectory of the oil jet prior to surface impingement. The high-resolution LES simulation, however, is superior in capturing small scale details and heat transfer between the free jet and surrounding air.https://www.stet-review.org/articles/stet/full_html/2022/01/stet210308/stet210308.htmllarge eddy simulationelectric motorcomputational fluid dynamicsvolume of fluid methodadaptive mesh refinement |
spellingShingle | Grover Ronald O. Yang Xiaofeng Parrish Scott Nocivelli Lorenzo Asztalos Katherine J. Som Sibendu Li Yanheng Burns Cooper Van Gilder John Attal Nitesh Avanessian Oshin CFD simulations of electric motor end ring cooling for improved thermal management Science and Technology for Energy Transition large eddy simulation electric motor computational fluid dynamics volume of fluid method adaptive mesh refinement |
title | CFD simulations of electric motor end ring cooling for improved thermal management |
title_full | CFD simulations of electric motor end ring cooling for improved thermal management |
title_fullStr | CFD simulations of electric motor end ring cooling for improved thermal management |
title_full_unstemmed | CFD simulations of electric motor end ring cooling for improved thermal management |
title_short | CFD simulations of electric motor end ring cooling for improved thermal management |
title_sort | cfd simulations of electric motor end ring cooling for improved thermal management |
topic | large eddy simulation electric motor computational fluid dynamics volume of fluid method adaptive mesh refinement |
url | https://www.stet-review.org/articles/stet/full_html/2022/01/stet210308/stet210308.html |
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