Numerical and Experimental Investigation of Effect of Tongue Shape on Turbine Reliability

Turbine housing in turbocharger is a critical part which must withstand severe cyclic mechanical and thermal load throughout its service life. The combination of thermal transients with mechanical load cycles results in a complex evolution of damage, leading to thermal mechanical fatigue (TMF) of the material and, after a certain number of loading cycles, to failure of the component. The volute tongue at radial turbine housing is a key feature which is frequently the first location subject to thermal crack failure due to turbine design. Design of tongue is of importance to improve system's TMF performance. In this work, two tongues including square and elliptic shape on radial turbine fatigue are studied. TMF performance is evaluated by finite element analysis (FEA). In particular, experimental method is carried out in order to validate the simulation model. The good agreement is found between numerical and experimental results. Based on both numerical and experimental investigation we identify and in particular quantify the influence of tongue shape which can raise the design quality of turbine housing in the preliminary design stage.