Experimental study of the effects of repetitive surge condition on turbocharger performance

When the mass flow rate through the compressor is reduced at a constant pressure ratio, mass flow rate will drop to an extent that the complete reversal of flow and surge occurs. Recently many research focuses on turbocharger surge, however, there are not enough investigation on the effect of surge on the performance of the turbocharger. The aim of the paper is to investigate the effect of repetitive surge condition on the performance of gasoline engine turbocharger. An experimental investigation has been performed on the turbocharger test cell for 3 different shaft speeds. Turbine and compressor power and efficiency have been investigated while turbocharger was performed in the surge zone. After 4 times repetition of the test procedure, turbocharger failure occurred. Results show that at 180000 rpm and minimum flow, the pressure ratio of compressor decreased by 7 percent after repetitive surge condition. Moreover, turbocharger failure analysis has been performed for the turbocharger which is repeatedly in the surge zone. Investigation shows that there the reason for failure was excessive axial clearance which caused high-temperature signs on the thrust bearing.