Session: 06-02 Pressure Gain Combustion

Paper Number: 154259

Large-Eddy Simulation of Traversing Jet Re-Ignition in a Wave-Rotor Constant-Volume Combustor 

A three-dimensional detailed chemistry and turbulent flow simulation is conducted to investigate re-ignition in a wave-rotor combustor when a traversing jet from a fixed prechamber torch ignition source crosses one end of a combustion channel. The formation of multiple vortices that mix hot gas with fuel-air mixture mediate the initiation of a  turbulent premixed flame. Two configurations of prechamber geometries are considered in this study to deliver hot reactive gas into the constant-volume combustor with premixed ethylene and air reactants. The fluid dynamics and combustion are simulated in one wave rotor channel and the pre-combustion chamber using Large Eddy Simulation (LES) model. The role of the prechamber nozzles on the ignition delay time are investigated, with results showing substantial increase in ignition delay time with jet having inclined-converging exit orifice compared to jet of converging-diverging nozzle. The effects of the vortex structure including head vortex rings, pinch-off separation process and Kelvin-Helmholtz vortices on the onset of heat release are investigated along the axial and radial stream components. The sensitivity of near-field entrainment on turbulent mixing properties and ignition are evaluated. Time history of the strain rate measured  downstream reveals localized flame extinction triggered by extended interaction between the vortices and flame reaction zone.

Keywords: Large Eddy Simulation, wave rotor combustor, vortex structure, turbulent jet ignition, ignition mechanism.

Presenting Author: Rasheed Yinusa Purdue University

Presenting Author Biography: Rasheed K. Yinusa is a PhD Candidate at Purdue University. He completed his B. Eng. in mechanical engineering at the Federal University of Technology Akure, Nigeria, and earned his master’s degree at Howard University, specializing in convective heat transfer research. Rasheed currently leads On-Board diagnostics certification and compliance work at Cummins. His doctorate research focuses on the simulation of prechamber turbulent jet ignition processes and combustion in constant volume combustors and pressure-gain systems.

Authors:

Rasheed Yinusa Purdue University
M. Razi Nalim Purdue University