Experimental Study of the Performance of a Nozzle-less Volute Casing for Turbocharger Turbines

The performance criteria for nozzle-less volute casings have been identified. The results of a study of flow in a single entry nozzle-less volute casing are given. It has been shown that the design of the entry region, in particular of the tongue, is very important for creating the desired vortex. The results show that a casing designed in accordance with the free vortex theory would not meet the performance criteria.