Numerical Investigation of Shrouded Ejector-Enhanced Pulse Combustor Performance at High Pressure

Abstract

A computational fluid dynamics investigation of a pressure-gain combustor system for gas turbine applications is described. The system consists of a valved pulse combustor and an ejector, housed within a shroud. The computational fluid dynamics solver is first validated by comparing its output to experimental measurements done on a pulse combustor operating at sea-level static conditions. Subsequently, the combustor inlet pressure and temperature are increased in the simulations to more closely align with those seen downstream of a compressor. Several parameters that influence combustor performance are then varied in order to demonstrate the potential benefit of optimization efforts. Emissions calculations are also performed. It is found that efficient high-pressure operation is possible and that system pressure gain of nearly 3% (at gas turbine compatible combustor temperature ratios) is achievable, with nearly smooth exit flow, having a competitive emission index. The potential for pulse combustors to achieve ultra-low levels of emissions at high-pressure conditions is also demonstrated.