Pressure-Gain Combustion: Part I—Model Development

A model for aerodynamically valved pulse combustion is presented. Particular emphasis is placed on using the model equations to identify characteristic length and time scales relevant to the design of pressure-gain combustors for gas turbine applications. The model is a control volume description of conservation laws for several regions of the pulse combustor. Combustion is modeled as a bimolecular reaction. Mixing between the fresh charge and the combustion products is modeled using a turbulent eddy time estimated from the combustor geometry and flow conditions. The model equations identify two characteristic lengths, which should be held constant during combustor scaleup, as well as certain exceptions to this approach. The effect of ambient operating pressure and inlet air temperature is also discussed.