Krishan K. Ahuja

TL;DR: In this article, four different approaches are used to determine experimentally the sources of jet mixing noise: spectral and directional information measured by a single microphone in the far field, fine-scale turbulence, large turbulence structures of the jet flow, and a mirror microphone is used to measure the noise source distribution along the lengths of high speed jets.

TL;DR: In this article, a new feedback mechanism is proposed for discrete tone generation by impinging jets, which is achieved by upstream-propagating waves associated with the lowest-order intrinsic neutral wave modes of the jet flow.

TL;DR: In this article, it was found by direct numerical simulation that sound waves at high intensity can induce vortex shedding at the mouths of the resonators of an acoustic liner, which is a dominant dissipation mechanism of resonant acoustic liners.

TL;DR: In this paper, four different approaches are used to determine experimentally the sources of jet noise: spectral and directional information measured by a single microphone in the far field, fine scale turbulence, large turbulence structures of the jet flow, and a mirror microphone is used to measure the noise source distribution along the lengths of high speed jets.

TL;DR: In this paper, measurements of the noise field from three 1.52, 2.4 and 2.84 inch diameter subsonic cold-air jets are presented in the anechoic chamber of National Gas Turbine Establishment, Pyestock, on a test rig with a very large contraction ratio (maximum 250:1, minimum 70:1).