The effects of interblade phase angle on pitch oscillating, transonic, cascade flows

Allison, SD

Abstract

A series of compressor blades, aligned as a cascade, situated in a transonic flow has been studied using a two-dimensional Computational Fluid Dynamics (CFD)
technique.
An objective of the research was to discover, using a CFD code, how the total aerodynamic stability of a compressor cascade was affected by blade pitching oscillations, vibrating at certain interblade phase angles and oscillation frequencies.
The analysis focused on the way in which the interblade phase angle, a, is likely to affect the stability of the cascade over a range of oscillation frequencies between
200Hz and 1 OOOHz, for a series of interblade phase angles between 0° and 180°. Two turbulence models were assessed to determine the sensitivity of turbulence coding, namely the Baldwin-Lomax and Johnson-King models. A validation of the CFD code against published data from the NASA Lewis Research Centre was carried out.
The interaction of the passage shock, formed between the blades, and on the positive pressure surface of the blade was shown to have the greatest influence on the aerodynamic stability of the cascade; the shocks formed on the suction side had a somewhat smaller effect. Any flow separation, on either the suction or pressure surfaces, was also shown to decrease cascade stability.

Citation

Allison, S. The effects of interblade phase angle on pitch oscillating, transonic, cascade flows. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Oct 3, 2012
• Award Date: Jan 1, 2011