Micro-turbines/expanders are growing in the fields of waste heat recovery, micro power generation and energy harvesting. Traditional turbines impose problems of complex nature of blades, balancing issues and high cost. The aim of this paper is to investigate feasibility of multiple disk Tesla air turbo expanders by extensively performing experimental and computational analysis. A flexible test rig of 200 W net mechanical power is developed with speed of rotation ranging from 10000 to 40000 rpm. The results of the experiments are presented and discussed by varying significant geometrical parameters of the prototype. A 3D computational fluid dynamic (CFD) analysis of rotor and stator with real fluid gas assumption is performed to characterize flow in the Tesla micro expander. Experimental turbine efficiencies found to be lower compared to the rotor efficiencies analyzed theoretically. The gap in the efficiency is discussed by analyzing CFD and experimental results.
