Numerical study of a two-stage turbine characteristic under pulsating flow conditions

다국어 초록 (Multilingual Abstract)

With developments of turbo-compounding and two-stage turbocharging technologies, two-stage turbine is increasingly applied in automotive engines. This paper numerically investigates the characteristic of a two-stage turbine on a turbo-compound engine under pulsating flow conditions. The behaviors of turbine stages with the swallowing capacity ratio (SR) equals to 2.0, under low, mid and high load conditions were studied. Results show that the Low pressure turbine (LPT) is more sensitive to the pulsating flow, especially at low load conditions, compared with High pressure turbine (HPT). It is caused by the dramatic change of velocity ratio in LPT. Results also show that the load split between HPT and LPT under pulsating flow conditions deviates from that at quasi-steady conditions, indicating the different behaviors of the two-stage turbine under pulsating conditions.

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