Anisotropy and relaminarisation of the turbulent flow near a rotating cylindrical cavity wall

Research output: Contribution to journalResearch articleContributedpeer-review

Abstract

Rotor internal cooling is a new concept for high power density electric vehicle drives. A turbulent pipe flow is injected into a cylindrical cavity in the rotor shaft of the motor. The flow is deflected in the cavity, accelerated in circumferential direction by the rotor wall and exits through an annular duct with the outer wall rotating. Due to the opposing effects of rotation on turbulence, a complex transitional flow develops. The strong shear layer in the jet region causes high turbulence production. On the other hand, these fluctuations are damped by the centrifugal forces due to the flow rotation. To investigate the influences of the rotation on the turbulence properties and the mean flow, highly resolved large eddy simulations are performed. It is shown that the turbulence production and attenuation due to rotation affect different components of the Reynolds shear stress tensor. This results in highly anisotropic turbulence. In certain areas, where the turbulence attenuation is strongest, the flow even relaminarises. Since the cooling efficiency depends on the turbulent heat transfer of the flow, the local turbulence characteristics are key quantities for the cooling application.

Details

Original languageEnglish
Pages (from-to)e202300263
JournalPAMM
Volume23
Issue number3
Publication statusPublished - Nov 2023
Peer-reviewedYes

External IDs

Mendeley caa34416-34ba-3f79-8990-b5eee31858f4
unpaywall 10.1002/pamm.202300263

Keywords

Library keywords