Experimental study of shock structure of particle-laden under expanded free jet

An experimental investigation of under expanded particle-laden jet flows is conducted. The key parameter varied in the study is the mass loading ratio: the proportion of particle mass flow to air mass flow. A robust experimental setup is designed, calibrated, and built to produce repeatable data. Schlieren imagery with a horizontal knife edge and a high speed Chronos camera were used to analyze the shock structure of the resulting under expandedjet. Comparisons were made between Mach disc offset distance for unladen and laden flow. Contrary to literature, it is found that the Mach disc distance in particle-laden flow is dependent on both nozzle pressure ratio and mass loading ratio. Unladen data shows good agreement with literature and the Mach disc in laden flow is seen to move upstream with the addition of particles. Only qualitative comparisons are made to limited literature studies as mass loading ratios tested in this study, 0.5 – 2, were higher than those of literature: < 1. Further work is necessary to find a detailed empirical relationship between Mach disc offset distance, mass loading ratio, and nozzle pressure ratio.