A Comprehensive investigation of volumetric heating Effects on supersonic nozzle flow patterns and condensation shocks, Considering Non-Equilibrium condensation and gas dynamics characteristics

Supersonic nozzles are widely used in industry, handling compressible flows ranging from subsonic to supersonic speeds. This study introduces a mathematical model that focuses on the transient phase change phenomenon and the formation of liquid nanodroplets to predict the condensing flow regime within the Eulerian-Eulerian framework. The research then examines the effect of volumetric heating applied to specific sections of the supersonic nozzle on both two-phase model (TPM) and single-phase model (SPM) simulations. The results highlight the significant impact of the area where volumetric heating is applied on the flow patterns of TPM and SPM. Volumetric heating plays a crucial role in shifting the condensation shock downstream in the supersonic nozzle. Frictional entropy generation emerges as the primary contributor to entropy production in the supersonic nozzle, a factor mitigated by volumetric heating. Applying 20 MW/m2 of volumetric heating across the entire nozzle prevents two-phase flow, maintaining single-phase conditions. This application results in reductions of approximately 4.6 % in the mass flow rate, 8.4 % in frictional entropy generation, 5.7 % in thermal entropy generation, and 6.5 % in total entropy generation compared to the unheated state.