Experimental Study on Nonuniform Hartmann Resonators

Hartmann whistle, sometimes also known as Powered Resonance Tube, refers to a device that employs a high speed jet impinging on a cavity, which is open at one end and closed at the other. This device is capable of producing high amplitude tones over a wide range of frequencies. The aero-acoustic field produced by Hartmann whistle can have very high amplitudes. These strong unsteady flow fields can be used for Active Flow Control (AFC) applications. Advantage of using such a device is that, it employs no moving part which in turn, makes it more reliable and safe. This device is also capable of producing resonance induced heating at the closed end of the tube, where the temperatures can reach as high as 1000K. The intended work primarily focuses on the performance of nonuniform Hartmann whistle at different nozzle pressure ratios. In the full paper, results for aero-acoustic and heating effects in a nonuniform Hartmann resonator will be presented. The results will include the amplitude of sound, the tonal quality in terms of frequency content and the temperature achieved at the closed end.