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Unsteady propeller flows due to turbulence ingestion

Published online by Cambridge University Press:  04 July 2016

J. M. Harden
Affiliation:
Department of Aerospace EngineeringUniversity of Bristol Bristol, UK
M. V. Lowson
Affiliation:
Department of Aerospace EngineeringUniversity of Bristol Bristol, UK

Abstract

A laser doppler anemometer (LDA) was configured to provide simultaneous ID velocity readings from two separate points in the contracting flow regime upstream of 0·63 m diameter model propeller operating under high thrust conditions. Cross-correlations between the velocity signals were used to map the progress of turbulent eddy structures throughout the distortion, even within the highly oscillatory region close to the blades. These measurements were used to provide data on the strength and velocity of the eddies, as well as their average size and shape in two dimensions. The results show both elongation of the turbulent structures in the streamwise direction and distortion along their length, caused by the contracting flow and the high Reynolds stress. Linearised isotropic theory was used to predict the changes in the turbulent kinetic energies, and was found to be accurate for the longitudinal component only.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1998 

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