We present a study of the flame-embedding concept, introduced in [1] as an efficient approach for large-eddy simulation of turbulent combustion at high Reynolds and Damköhler numbers. In flame embedding, the combustion zone is modeled as an unsteady flame modified by the local tangential strain rate, with the latter extracted every time step from the flow field simulations. The flame structure ...

An enthalpy-balance fuel-grain regression model is presented. The regression model, based on the longitudinally averaged fuel recession rates, is shown to accurately predict the chamber pressure, thrust and specific impulse performance of small and medium scale hybrid rocket motors. The key to the model predictions is the longitudinal enthalpy balance between the fuel grain heat of ablation and...

Abstract An axial vane rotary engine (AVRE) is a novel type of engines. The positive displacement mechanism that permits the four “stroke” action to occur in one revolution shaft with minimum number moving components comparison reciprocating In this paper, two-zone combustion model developed for spark ignition AVRE. chamber divided into burned and unburned zones differential equations are chang...

One of the important problems in reducing pollutant emission from diesel engines is trade-off between soot and NOx. Split injection is one of the most powerful tools that decrease soot and NOx emissions simultaneously. At the present work, the effect of split injection on the combustion process and emissions of a direct-injection diesel engine under full-load conditions is investigated by the c...

One strategy to decrease the amount of oxides of nitrogen formed and emitted from certain combustion devices, such as the internal combustion engine, is to recirculate and introduce a portion of the unburned product gases with the air and fuel. The effect of the re-circulated gases is to decrease the maximum temperatures in the flame zone, and hence decrease NOx formation. However, dilution of ...

An existing in-cylinder thermal regeneration concept for Diesel engines is examined for the roles of the porous insert motion and the fuel injection strategies on the fuel evaporation and combustion and on the engine efficiency. While the heated air emanating from the insert enhances fuel evaporation resulting in a superadiabatic combustion process (thus increasing thermal efficiency), the corr...

Non-intrusive hydroxyl radical (OH) planar laser-induced fluorescence (PLIF) measurements were obtained in configuration C of the University of Virginia supersonic combustion experiment. The combustion of hydrogen fuel injected through an unswept compression ramp into a supersonic cross-flow was imaged over a range of streamwise positions. Images were corrected for optical distortion, variation...