Passive Separation Control with Blade-End Slots in a Highly Loaded Compressor Cascade

AIAA Journal ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Yumeng Tang ◽  
Yangwei Liu ◽  
Lipeng Lu ◽  
Huawei Lu ◽  
Ming Wang
Keyword(s):  
Separation Control ◽  
Compressor Cascade ◽  
Passive Separation ◽  
Highly Loaded

Experimental investigation on separation control by slot jet in highly loaded compressor cascade

2017 ◽  
Vol 232 (9) ◽  
pp. 1704-1714 ◽  
Author(s):  
Hu Jiaguo ◽  
Wang Rugen ◽  
Li Renkang ◽  
He Chen ◽  
Li Qiushi
Keyword(s):  
High Efficiency ◽  
Incidence Angle ◽  
Suction Side ◽  
Separation Control ◽  
Compressor Cascade ◽  
Turning Angle ◽  
Control Approach ◽  
Stable Operating ◽  
Operating Margin ◽  
Highly Loaded

Separation control in compressor cascade is very significant for modern high efficiency compressor. This paper introduces a separation control approach using self-supplied jet in a highly loaded cascade. A novel arc slot is created into the cascade at the full span range, which connects the flow fields between the pressure and suction side. Because of the pressure difference, the slot enables to induce the jet flow into the suction side separation. Experiments are conducted to evaluate the separation control effects and preliminarily study the mechanism. The results show that the slot cascade acquires more ordered outflow by reducing the suction side separation and suppressing the complex vortices. Due to the great reduction of the separation, the total loss significantly decreases by 21.9% and the flow turning angle increases by 2.1° in average. According to the improvements of the cascade performance, the stable operating margin of the highly loaded cascade is greatly improved at least 3° in terms of the incidence angle.

Flow separation control on a highly loaded compressor cascade using endwall synthetic jets

2017 ◽  
Vol 232 (11) ◽  
pp. 2059-2075 ◽  
Author(s):  
Yong Qin ◽  
Yanping Song ◽  
Ruoyu Wang ◽  
Huaping Liu ◽  
Fu Chen
Keyword(s):  
Boundary Layer ◽  
Flow Separation ◽  
Pressure Rise ◽  
Synthetic Jets ◽  
Separation Control ◽  
Compressor Cascade ◽  
Flow Separation Control ◽  
Maximum Loss ◽  
Wall Flows ◽  
Highly Loaded

This paper presents flow separation control conducted on a highly loaded compressor stator cascade using endwall synthetic jets. Numerical methods are employed and mechanisms of endwall synthetic jets in improving the cascade performance are discussed in detail. The influence of several actuation parameters is also investigated. Results show that endwall synthetic jets are able to improve the flows in the blade passage significantly, a maximum loss reduction of 21.63% and a pressure rise increment of 5.60% are obtained at design condition. Apart from energizing the low momentum fluid inside endwall boundary layer by streamwise momentum addition, endwall synthetic jets could induce a streamwise jet vortex and impede the transverse movement of endwall boundary layer through upwash and downwash. Hence, at the expense of slightly degraded near-wall flows, the formation and further evolution of passage vortex would be delayed and flows in the midspan region would be improved notably. The effectiveness of endwall synthetic jets relies on the proper selection of actuation position and jet angle. Flow control turns out to be the most efficient when the actuator is positioned at just upstream of corner separation region with a relatively small jet angle, and a large enough injected momentum is also necessary. Additionally, the adaptability of the actuation at off-design conditions is validated in the present study.

Corner Separation Control in a Highly Loaded Compressor Cascade Using Plasma Aerodynamic Actuation

2012 ◽  
Author(s):  
Yun Wu ◽  
Xiao-hu Zhao ◽  
Ying-hong Li ◽  
Jun Li
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
Total Pressure Loss ◽  
Separation Control ◽  
Compressor Cascade ◽  
Control Effect ◽  
Suction Surface ◽  
Corner Separation ◽  
Pressure Loss Coefficient ◽  
Highly Loaded

Corner separation, which forms over the suction surface and endwall corner of a blade passage, causes significant total pressure loss in highly loaded compressors. Plasma flow control, based on the plasma aerodynamic actuation, is a novel active flow control technique to improve aircrafts’ aerodynamic characteristics and propulsion efficiency. This paper reports computational and experimental results on using three types of plasma aerodynamic actuation (PAA) to control the corner separation in a highly loaded, low speed, linear compressor cascade. Reynolds-Averaged Navier-Stokes simulations were performed to optimize the PAA arrangement. The PAA was generated by a microsecond or nanosecond dielectric barrier discharge in wind tunnel experiments. The total pressure loss coefficient distribution was adopted to evaluate the corner separation control effect. The control effect of pitch-wise PAA on the endwall, in terms of relative reduction of the pitch-wise averaged total pressure loss coefficient in the wake, is much better than that of stream-wise PAA on the suction surface. When both pitch-wise PAA on the endwall and stream-wise PAA on the suction surface are turned on simultaneously, the control effect is the best among all three types of PAA. The main effect of pitch-wise PAA on the endwall is to inhibit the crossflow from neighboring pressure surface to the suction surface, whilest the main effect of stream-wise PAA on the suction surface is to inhibit the boundary layer accumulation and separation. Compared to microsecond discharge PAA, nanosecond discharge PAA is more effective at higher freestream velocity. The mechanisms for nanosecond discharge and microsecond discharge PAA are different for corner separation control.

Numerical Investigation of Passive Flow Control Using Wavy Blades in a Highly-Loaded Compressor Cascade

2018 ◽  
Author(s):  
Bo Wang ◽  
Yanhui Wu ◽  
Kai Liu
Keyword(s):  
Numerical Investigation ◽  
Flow Structure ◽  
Cross Flow ◽  
Leading Edge ◽  
Control Flow ◽  
Streamwise Vortices ◽  
Compressor Cascade ◽  
Control Effect ◽  
Suction Surface ◽  
Highly Loaded

Driven by the need to control flow separations in highly loaded compressors, a numerical investigation is carried out to study the control effect of wavy blades in a linear compressor cascade. Two types of wavy blades are studied with wavy blade-A having a sinusoidal leading edge, while wavy blade-B having pitchwise sinusoidal variation in the stacking line. The influence of wavy blades on the cascade performance is evaluated at incidences from −1° to +9°. For the wavy blade-A with suitable waviness parameters, the cascade diffusion capacity is enhanced accompanied by the loss reduction under high incidence conditions where 2D separation is the dominant flow structure on the suction surface of the unmodified blade. For well-designed wavy blade-B, the improvement of cascade performance is achieved under low incidence conditions where 3D corner separation is the dominant flow structure on the suction surface of the baseline blade. The influence of waviness parameters on the control effect is also discussed by comparing the performance of cascades with different wavy blade configurations. Detailed analysis of the predicted flow field shows that both the wavy blade-A and wavy blade-B have capacity to control flow separation in the cascade but their control mechanism are different. For wavy blade-A, the wavy leading edge results in the formation of counter-rotating streamwise vortices downstream of trough. These streamwise vortices can not only enhance momentum exchange between the outer flow and blade boundary layer, but also act as the suction surface fence to hamper the upwash of low momentum fluid driven by cross flow. For wavy blade-B, the wavy surface on the blade leads to a reduction of the cross flow upwash by influencing the spanwise distribution of the suction surface static pressure and guiding the upwash flow.

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