Abstract
Flow instability in a centrifugal fan was studied using energy gradient theory. Numerical simulation was performed for the threedimensional turbulent flow field in a centrifugal fan. The flow is governed by the three-dimensional incompressible Navier-Stokes equations coupled with the RNG k-ε turbulent model. The finite volume method was used to discretize the governing equations and the Semi-implicit method for pressure linked equation (SIMPLE) algorithm is employed to iterate the system of the equations. The interior flow field in the centrifugal fan and the distribution of the energy gradient function K are obtained at different flow rates. According to the energy gradient method, the area with larger value of K is the place where the flow loses stability easier. The results show that instability is easier to generate in the regions of impeller outlet and volute tongue. The air flow near the hub is more stable than that near the shroud. That is due to the influences of variations of the velocity and the inlet angle along the axial direction. With the decrease of the flow rate, instability zone in a blade channel moves to the impeller inlet from the outlet and the unstable regions in different channels develop in opposite direction to the rotation of impeller.
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Recommended by Guest Editor Hyung Hee Cho and Yulin Wu
Meina Xiao received her M.S. from Zhejiang Sci-Tech University in 2013. Since then, she has been a Ph.D. student in the Faculty of Mechanical Engineering and Automation at Zhejiang Sci-Tech University. Her research interests include computational fluid dynamics, fluid mechanics and turbomachinery.
Hua-Shu Dou received his Ph.D. from Beijing University of Aeronautics and Astronautics in 1991. Since 2011, he has been a professor in the Faculty of Mechanical Engineering and Automation at Zhejiang Sci-Tech University. His main areas of interest are computational fluid dynamics, fluid mechanics, aerodynamics, turbomachinery, non-Newtonian fluid mechanics as well as combustion and detonation.
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Xiao, M., Xiao, Q., Dou, HS. et al. Study of flow instability in a centrifugal fan based on energy gradient theory. J Mech Sci Technol 30, 507–517 (2016). https://doi.org/10.1007/s12206-016-0103-z
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DOI: https://doi.org/10.1007/s12206-016-0103-z