Numerical study of the influence of splitter geometry on secondary flow control

Abstract

In turbmachinery, splitters are used to control secondary flow and to improve the aerodynamic performance of outlet guide vane (OGV) of axial fan. However, there is few information in the open literature focusing on the effect of the splitter geometry on the secondary flow control. In this work, the numerical investigations were performed for NACA 65-010 profile with different splitters. The spacing ratio of the main blade was 1, the spacing between the splitters and the main blade was 30mm. Three different splitters were compared to investigate the effect of the splitter geometry on secondary flow control. The flow structures near the end-wall, the streamlines on the suction surface of blade and the distribution of the flow losses on the trailing edge of blade was shown and discussed. The results showed the splitters can control the secondary flow and reduce the area of the high flow losses at the junction of end-wall and blade. However, the flow separation of the splitters also causes flow losses in the wake behind the splitters. Therefore, only the specific configuration of splitters can reduce the flow losses of the blade.

Numerical Investigation on the Secondary Flow Control by Using Splitters at Different Positions with Respect to the Main Blade

“…The fences with large height produce additional flow loss due to the reverse flow between the fences and the flow on the endwall behind the fences. Splitter [22][23][24] Reduce the end-wall loss from the mixing out of secondary flow vortices.…”

“…The velocity of inflow was smaller than Mach number 0.3, so the inflow was considered as incompressible (ρ is consistent). The turbulent intensity was set as 2%, which was tested in the wind tunnel in our lab [23,24]. The turbulent length was set as 0.014 m [24].…”

“…6. The inlet velocity profile in the CFD was fitted by the measurement results of the free field measurement [23].…”

A Numerical Investigation on the Influence of the Circular Ring on the Aerodynamic Noise Generated by a Cooling Fan

“…Recently, the research group of Bian et al [26][27][28] tried to study the flow loss and flow structure of the blade by numerical and experimental investigations and tried to investigate the influence of the splitter geometry on the secondary flow control.…”

Numerical investigation on the endwall fences with varying geometrical parameters on secondary flow control

“…Bian et al 18,19 detected the effect of fence geometry and fence position on the secondary flow reduction. Their study demonstrated that the fences could be used to reduce the secondary flow loss; however, the fences also had an additional flow loss, which is induced by the flow separation of the fences.…”