CUED Publications database

Roughness induced transition in low pressure turbines

Sengupta, A and Vadlamani, NR and Tucker, P (2017) Roughness induced transition in low pressure turbines. In: UNSPECIFIED.

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The transition of a separated shear layer over a at plate in presence of free-stream turbulence (FST) and regular three-dimensional (3D) roughness elements, is numerically investigated. A at plate with a contoured inviscid upper wall imposes the necessary streamwise pressure gradient to simulate the suction surface of a ‘ultra high-lift’ low-pressure turbine (LPT) blade. Results obtained from the current investigation compare favourably with extensive experimental and numerical data of previous investigations. The flow physics surrounding the transition process is examined. The benefits associated with the suppression of the separation bubble by introducing FST and surface roughness is established for the blade profile. The instantaneous flow features are an essential tool to identify the various streak formations associated with introduction of upstream disturbance. The turbulent kinetic energy budget is obtained for the various test cases and the individual and cumulative effect of FST and roughness is shown.

Item Type: Conference or Workshop Item (UNSPECIFIED)
Divisions: Div A > Fluid Mechanics
Div A > Turbomachinery
Depositing User: Cron Job
Date Deposited: 17 Jul 2017 19:26
Last Modified: 22 Jul 2021 04:19
DOI: 10.2514/6.2017-0303