Experimental and numerical study of oxygen-hydrogen rocket flame response to transverse acoustic excitation

The response of an oxygen-hydrogen flame to transverse acoustic velocity forcing is investigated using a combination of experimental analysis and numerical modelling. An experimental rocket combustor is used to study the response of oxygen-hydrogen flames to acoustic forcing representative of high frequency combustion instabilities. Optical datasets were analysed to identify the response of the flame to a transverse acoustic velocity disturbance using a multi-variable DMD method. As the optical access only allows for 2D imaging, CFD modelling of a representative single injector under forcing are emploiyed to gain insight into the three-dimensional features of the flow field. The numerical results successfully captured the exponential reduction in LOX core length as a function of the transverse acoustic amplitude that was observed experimentally. The CFD result show the excited LOX jet develops into a flattened and widened structure normal to the imposed disturbance. The complementary numerical and experimental analyses provide further insight into the transverse flame response.