Hot surface ignition was examined using a variety of heat sources in a series of premixed hydrocarbon, hydrogen, and air mixtures. Building off previous work, hexane-air, heptane-air and hydrogen-air experiments were performed in addition to the eventual hexane-hydrogen-air mixtures. Using high-speed schlieren photography, thermocouples, and a fast-response pressure transducer, flame characteri...

This research supported by the U.S. Army Research Office examines a myriad of facets of lifted hydrocarbon jet flames in the presence of air co-flow. At a certain jet exit velocity, a flame will lift from the fuel nozzle and stabilize at some downstream position. The partially-premixed flame front of the lifted flame oscillates, with the oscillations becoming greater in flames stabilized furthe...

The characteristics of the combustion temperature, flow velocity, CO distribution and NOx emissions of a 10 MW gas burner at different primary to secondary air ratios are numerically studied using computational fluid dynamics software Fluent. The results indicate that the primary to secondary air ratio in gas burner determines the combustion quality through influencing some parameters directly,...

In this work, the effects of the electric fields on the flame propagation and combustion characteristics of lean premixed methane–air mixtures were experimentally investigated in a constant volume chamber. Results show that the flame front is remarkably stretched by the applied electric field, the stretched flame propagation velocity and the average flame propagation velocity are all accelerate...

A new facility has been built at the University of Michigan to study shear coaxial combusting gas-gas injection in a rocket combustion chamber. This facility, capable of chamber pressures of 10 atmospheres, is used to obtain a better understanding of the complex fluid dynamics and combustion processes found in rocket combustion chambers and to provide data to assess NASA’s computational fluid d...

The purpose of this work is to highlight the importance of taking into account the two-way interaction between flame and acoustics in the prediction of combustion noise generated by enclosed turbulent flames. It is argued that in general the power spectral density (PSD) of noise inside a combustion chamber can be determined accurately only if the influence of acoustics on the flame is considere...

This paper presents an application of fuzzy logics for controlling the combustion flame of a premixed gas burner. The control objective is to achieve a good characteristic of combustion flame by visualizing the colors of the flame while maintaining its size as desired. The fuzzy logic controller adjusts the flow rates of gas and air independently through two stepper-driven needle valves. A CCD ...

The acoustic power of an oscillating flame is measured. A turbulent premixed propane/air flame is situated near a pressure antinode of a standing wave in a laboratory combustion chamber. This standing wave is generated by a piston. The fluctuating heat release of the flame will supply acoustic power to the standing wave as postulated by Rayleigh. This flame acoustic power is obtained by setting...

The lagrangian point of view is adopted to study turbulent premixed combustion. The evolution of the volume fraction of combustion products is established by the Reynolds transport theorem. It emerges that the burned-mass fraction is led by the turbulent particle motion, by the flame front velocity, and by the mean curvature of the flame front. A physical requirement connecting particle turbule...