عنوان مقاله [English]
This research is focused on scaling of a radial turbine for turbocharger of a lean combustion engine. One of the methods to decrease pollution is to reduce the exhaust temperature using lean combustion. So, more air should be entered the engine, and by increasing the air, the turbocharger should be changed for increased mass flow rate. In the first step, the turbine performance is simulated using a CFD solver, and the results are compared to the experimental data. Next, the turbine is scaled by four scenarios, and the turbines' performance is simulated using the CFD solver. In the first scenario, only the hub radius is decreased, and the mass flow is increased by 0.5%. In the second scenario, the hub radius decreases, and the shroud radius increases, and a 7% improvement is obtained. In the third scenario, the inlet and shroud radius increase while the hub radius decreases, and the mass flow is improved by 11%. In the fourth scenario, the geometry is changed freely, and a 20% increment is obtained.