Enhancing aerodynamic performances of a high-turning compressor cascade via boundary layer suction

Abstract

Experimental investigation was carried out to study the effect of suction positions and suction flow rates on the aerodynamic performance of a compressor cascade with a large camber angle. The ink-trace flow visualization was conducted and the flow fields of the cascade were also measured. Three types of boundary layer suction configurations are compared, i.e. the suction surface suction, the endwall suction and the compound suction. Experimental results show that the large amount of suction flow rate gains more losses reduction than the small amount for a certain proper suction configuration, but the speed of loss decline slows down as the suction flow rate goes on increasing. Boundary layer suction on the suction surface obviously enhances the ability of the boundary layer around the midspan to withstand the negative pressure gradient of the flow passage. The range of the suction surface corner is also decreased. If the suction slot locates in the corner separation region where severe separation has happened, the flow separation will be terminated at the slot and redevelop downstream. And boundary layer suction on the endwall mainly influences the endwall corner region in remarkably delaying, lessening and reorganizing the corner separation. While the whole flow field is remarkably improved at both midspan and the corner region in the compound suction schemes. At higher suction flow rates, the aerodynamic performance of the compressor cascade is better than that with boundary layer suction simply on the suction surface or on the endwall. When the suction flow rate is 1.5% of the inlet mass flow, the compound suction scheme achieves a maximum loss reduction of 17% compared with the cascade without boundary layer suction. boundary layer suction, high-turning diffusion cascade, suction flow rate, suction position, experimental investigation Citation:Guo S, Chen S W, Lu H W, et al. Enhancing aerodynamic performances of a high-turning compressor cascade via boundary layer suction.

Simplified compound suction schemes of an aspirated highly loaded compressor cascade

“…So EW1 is supposed to suck out more low-energy fluid and play a primary role in compound suction schemes. But the limited streamlines on the blades and EWs 18 illustrate that SS4 and EW1 & SS4 schemes are much more alike, especially when total suction flow rate is small, i.e., m suc = 0.5%. The suction flow distribution between EW1 & SS4 and corresponding aerodynamic parameters under different total suction flow rates in the EW1 and SS4 schemes are compared in Table 2 and Figure 10.…”

“…It should be emphasized that upper and lower boundaries of the vacuum are separately defined as wall and outlet with certain amount of mass flow rate, which is in line with the real condition of the corresponding experiments. 18 This kind of suction manner is denoted by “one-side-suction” in the followed text. It is confirmed after this study that the passage flow still keeps symmetrical under one-side-suction manner under proper design.…”

“…Before this investigation, the suction manners with one single suction slot on the suction surface of the blade (surface slot [SS]) or the EW had both been studied 18 and then a preferable configuration of each single-slot suction group was selected to form a compound suction configuration, i.e. EW1 & SS4 (EW1&SS4 stands for the compound suction configuration in which the endwall slot EW1 and the suction surface slot SS4 cooperate).…”

Effect of combined boundary layer suction on the separation control in a highly loaded transonic compressor cascade

“…They found that the reduced boundary layer will accelerate the migration of boundary layer, and the power generated by the suction plenum was reduced by the blade lean. Guo et al 20,21 investigated the different effects of compound and single scheme on the loss control in a subsonic stator. It suggested that both the boundary layer around the mid span and corner separation were removed by the suction slots.…”

Corner Separation Control by Boundary Layer Suction Applied to a Highly Loaded Axial Compressor Cascade

“…Guo et al [15][16][17] carried out experimental research both on the blade suction surface and on the endwall and found that the compound suction scheme works better with high suction flow rates compared with a single slot. A pitchwise endwall suction slot drilled at 13% chord upstream of the cascade was also investigated.…”