Fluidic control with microjets in dump combustors

This work explores the use of microjets as an effective means to improve the performance of dump combustors. Design studies are conducted for implementation of microjets using Reynolds averaged Navier-Stokes (RANS) equations in the framework of standard k- turbulence models. The effect of microjets on the primary flow and combustion is studied in two dump combustor geometries, namely round (axisymmetric) and planar dump combustors. Microjets are placed on the step face at a 45° angle. Compared to the baseline case without microjets, simulations show that adding microjets results in an increase in heat release rate of ∼22% and ∼140% in round and planar dump combustors, respectively. A parametric study is conducted by varying the microjet velocity. The finalized design for implementation of microjets, based on RANS simulations, has been used for experiments. The data collected from the experiments qualitatively confirm the trends predicted by the simulations.