Experimental Investigation of Airfoil Suction Side Flow Separation Control by Spanwise Nanosecond Actuation

2011 ◽  
Author(s):  
Liang Hua ◽  
Cao Shangen ◽  
Zhang Shengzhi ◽  
Bai Junxing
Keyword(s):  
Experimental Investigation ◽  
Flow Separation ◽  
Suction Side ◽  
Separation Control ◽  
Flow Separation Control ◽  
Side Flow

Coupled Blowing and Suction for Flow Separation Control

2019 ◽  
Author(s):  
M. Tadjfar ◽  
D. J. Kamari
Keyword(s):  
Boundary Layer ◽  
Reynolds Number ◽  
Flow Field ◽  
Turbulence Model ◽  
Flow Separation ◽  
Active Flow Control ◽  
Suction Side ◽  
Separation Control ◽  
Flow Separation Control ◽  
Active Flow

Abstract The effects of applying a coupled unsteady blowing and suction combination over SD7003 airfoil at Reynolds number of 60,000 at an angle of attack of 13°, where a large separation on the suction side of the airfoil existed, was considered to investigate active flow control (AFC) mechanism. URANS equations were employed to solve the flow field and k–ω SST was used as the turbulence model. The unsteady blowing and suction were implemented at an angle to the surface crossing the boundary layer (CBL). The influence of location and frequency of the blowing/suction jets were examined.

Numerical Investigations of Flow Separation Control for a Low Pressure Turbine Blade Using Steady and Pulsed Vortex Generator Jets

2010 ◽  
Author(s):  
Xiaomin Liu ◽  
Haiyang Zhou
Keyword(s):  
Turbine Blade ◽  
Flow Separation ◽  
Vortex Generator ◽  
Suction Side ◽  
Low Pressure ◽  
Pulse Frequency ◽  
Separation Control ◽  
Flow Separation Control ◽  
Low Pressure Turbine ◽  
Vortex Generator Jets

This paper investigated numerically the application of Vortex Generator Jets (VGJs) to control flow separation on the suction side of a low pressure turbine blade. Firstly, numerical simulations of flow separation for a LPT blade, which based on Menter’s SST k-ω turbulence model coupled with Langtry-Menter transition model, were performed for different Reynolds numbers Re∼100,000, 75,000, 50,000 and 25,000, for three freestream turbulence intensity (FSTI) of 0.08%, 2.35% and 6.0%. The pressure distributions around the turbine blade and streamline plots showing the flow separation were presented in this paper. Good agreement of the numerical and experimental results also showed the validity of the numerical scheme for simulating the flow separation occurring on a low pressure turbine blade. And then, steady Vortex Generator Jets (steady VGJs) having pitch angle of 30°, skew angle of 90°, blowing ratio of 2.0 were used to control the flow separation in the suction side of the low pressure turbine blade. Although steady VGJs have been illustrated to be extremely robust at suppressing low Reynolds number separation, the practical application of VGJs in the low pressure turbine engine is in the pulsed mode. The injection mass flow requirements of pulsed Vortex Generator Jets (pulsed VGJs) can be reduced drastically when similar flow control effect is obtained using steady VGJs. For pulsed VGJs, the pulse frequency has been found to be an important control parameter for the flow separation control. In this paper, cases with the duty cycle of 0.5 were studied for the pulse frequency ranging from 2.5Hz to 10Hz at Re = 25,000 and freestream turbulence level of 0.08%. The numerical results showed that pulsed VGJs can effectively reduce and even eliminate the flow separation on the blade suction surface while there is an optimal pulse frequency. The flow control mechanism of VGJs on LPT blade was also revealed.

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