Experimental and CFD analysis of multi nozzle ejector system for aircraft compact heat exchanger applications

Abstract

In the present study, analysis of multi-nozzle ejector systems for aircraft compact heat exchanger applications is performed. CFD procedure is validated with experimental data of a single-nozzle ejector. Experimentation is carried out with a multi-nozzle ejector to evaluate the performance of the system at ambient temperature (307 K). Based on the pressure drop data obtained from the experiment, the computational domain for CFD studies is simplified. Further the analysis of air ejector systems at higher operating temperature (813 K) is performed. Primary air inlet temperatures and pressure are varied as parameters. Velocity contour, pressure contour and temperature contours are plotted for cold and hot fluid cases. High pressure zones are observed in the mixing regime of primary and secondary fluid. Improper mixing of primary and secondary fluid is observed. The mass ratio is reduced with increase in primary pressure. Based on the CFD results at high temperature, the performance of the compact heat exchanger is computed using the heat exchanger carpet curve for the different secondary (cold) air flows induced by the ejector.