Citation:
Saddington AJ, Cabrita PM, Knowles K. (2005) Large-scale instabilities in a STOVL upwash fountain. InEngineering Turbulence Modelling and Experiments 6, January 2005, pp. 667-676
Abstract:
The fountain flow created by two underexpanded axisymmetric, turbulent jets
impinging on a ground plane was studied through the use of laser-based
experimental techniques. Velocity and turbulence data were acquired in the jet
and fountain flow regions using laser doppler velocimetry and particle image
velocimetry. Profiles of mean and rms velocities along the jet centreline are
presented for nozzle pressure ratios of two, three and four. The unsteady nature
of the fountain flow was examined and the presence of large-scale coherent
structures identified. A spectral analysis of the fountain flow data was
performed using the Welch method. The results have relevance to ongoing studies
of the fountain flow using large eddy simulation techniques.