Comparison of Valved-Pulsejet Combustion Operation Using Ethanol and Gasoline Fuels

This works intends to study the behavior of a valved-pulsejet combustion using gasoline and ethanol fuels with twelve different geometries. The study includes measurements of pressure and thrust. The twin-peak behavior that appears on The PCB (pressure inside the engine), thrust, and microphone (outside sound pressure) with both fuels. This suggest that there is another phenomenon accompanied the acoustic pressure waves inside the engine. The high amount of thrust associated with high peak pressure. Peak pressure points located on the upstream section of the engine for both fuels (Helmholtz-like modes). Ethanol fuel produces higher peak pressure values than gasoline. Thrust (and peak pressure) and are highly non-linear with respect to the geometrical factor of the pulsejet engine. Gasoline provides more stable and sustained operation than ethanol, due to the flammability characteristics of the ethanol at atmospheric condition.