Aerothermodynamics and Exergy Analysis in Radial Turbine With Heat Transfer

This study was motivated by the difficulties to assess the aerothermodynamic effects of heat transfer on the performance of turbocharger turbine by only looking at the global performance parameters, and by the lack of efforts to quantify the physical mechanisms associated with heat transfer. In this study, we aimed to investigate the sensitivity of performance to heat loss, to quantify the aerothermodynamic mechanisms associated with heat transfer and to study the available energy utilization by a turbocharger turbine. Exergy analysis was performed based on the predicted three-dimensional flow field by detached eddy simulation (DES). Our study showed that at a specified mass flow rate, (1) pressure ratio drop is less sensitive to heat loss as compared to turbine power reduction, (2) turbine power drop due to heat loss is relatively insignificant as compared to the exergy lost via heat transfer and thermal irreversibilities, and (3) a single-stage turbine is not an effective machine to harvest all the available exhaust energy in the system.