Tehnički glasnik, Vol. 9 No. 4, 2015.
Izvorni znanstveni članak
Numerical investigation of influence of tip clearance in mixed-flow compressor performance
Guo-jie Zhang
; School of Electric Power Engineer, Xuzhou, Jiangsu Province, China
Yi-min Li
; School of Electric Power Engineer, Xuzhou, Jiangsu Province, China
Zhong-ning Zhou
; School of Electric Power Engineer, Xuzhou, Jiangsu Province, China
Sažetak
In mixed-flow compressor, the leakage flow through the tip clearance generates the tip leakage vortex by the interaction with the main flow, and consequently makes the flow in the impeller passage more complex. Different tip clearances generate different intensity of disturbance to main flow. In this paper, numerical analysis is performed using a commercial code to investigate tip clearance effects on main flow. The performance of mixed-flow impeller with four different clearances between impeller and stationary shroud are evaluated and compared with experimental results. The impeller performance curves are obtained for different mass flow parameters with different tip clearances at design speed. The results show that the tip leakage flow strongly interacts with main flow and contributes to total pressure loss and performance reduction. The pressure and performance decrement are approximately linearly proportional to the gap between impeller and stationary shroud. Though the velocity vectors distribution, the computed results reveal that the intensity of the disturbance generated by the leakage flow interacts with the main flow has rather a large influence over efficiency. And the quantity of backflow is minimum when the tip clearance is 0.5 mm, while the 0.75mm tip clearance, by contrast, has a considerable effect on main flow by the interaction with leakage flow.
Ključne riječi
Mixed-flow compressor; tip clearance; efficiency; tip-leakage flow; numerical analysis
Hrčak ID:
149754
URI
Datum izdavanja:
15.12.2015.
Posjeta: 1.060 *