Theoretical investigation of pressure waves generated by heat addition in a gaseous medium
Implementing Organization
CO-Principal Investigator
Dr. T. John Tharakan
Liquid Propulsion Systems Centre (LPSC), Valiamala
Project Overview
Heat addition in a combustible mixture involves various processes. The first process is heating of the mixture. When the temperature reaches the auto-ignition temperature, the mixture ignites, and combustion occurs resulting in deflagration or detonation depending on whether the flame propagation velocity is subsonic or supersonic respectively. Both these processes can generate pressure waves which should be investigated theoretically to ensure they are not detrimental to the system. Once the mixture reaches the steady state, under certain conditions, combustion instability may set in. This may involve the constructive interaction of the heat release of the flame and the corresponding pressure perturbations which are amplified by the acoustics of the combustion chamber. Alternatively, the heat release fluctuations may generate entropy waves which can subsequently be converted to pressure waves when they are accelerated in a nozzle. The characteristics of pressure waves generated during the thermoacoustic and entropy-acoustic combustion instability is to be theoretically investigated in a detailed and comprehensive manner.