Numerical Investigation of Leading Edge Blowing and Optimization of the Slot Geometry for a Circulation Control Airfoil

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

Volume 2A: Turbomachinery ◽

10.1115/gt2018-76147 ◽

2018 ◽

Cited By ~ 1

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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Experimental and numerical investigation of jet impingement cooling onto a concave leading edge of a generic gas turbine blade

International Journal of Thermal Sciences ◽

10.1016/j.ijthermalsci.2021.106862 ◽

2021 ◽

Vol 164 ◽

pp. 106862

Author(s):

Marius Forster ◽

Bernhard Weigand

Keyword(s):

Numerical Investigation ◽

Gas Turbine ◽

Turbine Blade ◽

Leading Edge ◽

Jet Impingement ◽

Gas Turbine Blade ◽

Impingement Cooling

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Numerical Investigation of the Solidity Effect on Linear Compressor Cascades

Volume 2A: Turbomachinery ◽

10.1115/gt2014-25532 ◽

2014 ◽

Cited By ~ 1

Author(s):

J. Sans ◽

M. Resmini ◽

J.-F. Brouckaert ◽

S. Hiernaux

Keyword(s):

Numerical Investigation ◽

State Of The Art ◽

Leading Edge ◽

Operating Conditions ◽

Compressor Cascade ◽

Minimum Loss ◽

Low Speed ◽

High Mach ◽

The Stability ◽

The Impact

Solidity in compressors is defined as the ratio of the aerodynamic chord over the peripheral distance between two adjacent blades, the pitch. This parameter is simply the inverse of the pitch-to-chord ratio generally used in turbines. Solidity must be selected at the earliest design phase, i.e. at the level of the meridional design and represents a crucial step in the whole design process. Most of the existing studies on this topic rely on low-speed compressor cascade correlations from Carter or Lieblein. The aim of this work is to update those correlations for state-of-the-art controlled diffusion blades, and extend their application to high Mach number flow regimes more typical of modern compressors. Another objective is also to improve the physical understanding of the solidity effect on compressor performance and stability. A numerical investigation has been performed using the commercial software FINE/Turbo. Two different blade profiles were selected and investigated in the compressible flow regime as an extension to the low-speed data on which the correlations are based. The first cascade uses a standard double circular arc profile, extensively referenced in the literature, while the second configuration uses a state-of-the-art CDB, representative of low pressure compressor stator mid-span profile. Both profiles have been designed with the same inlet and outlet metal angles and the same maximum thickness but the camber and thickness distributions, the stagger angle and the leading edge geometry of the CDB have been optimized. The determination of minimum loss, optimum incidence and deviation is addressed and compared with existing correlations for both configurations and various Mach numbers that have been selected in order to match typical booster stall and choke operating conditions. The emphasis is set on the minimum loss performance at mid-span. The impact of the solidity on the operating range and the stability of the cascade are also studied.

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Numerical investigation of nozzle geometry influence on the vortex cooling in an actual gas turbine blade leading edge cooling system

Heat and Mass Transfer ◽

10.1007/s00231-021-03131-9 ◽

2021 ◽

Author(s):

Xiaojun Fan ◽

Yuan Xue

Keyword(s):

Numerical Investigation ◽

Gas Turbine ◽

Turbine Blade ◽

Cooling System ◽

Leading Edge ◽

Nozzle Geometry ◽

Gas Turbine Blade ◽

Blade Leading Edge

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Numerical Investigation on Leading Edge of Film Cooling Blade with Different Turbulence and Blowing Ratios

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1070-1072.1731 ◽

2014 ◽

Vol 1070-1072 ◽

pp. 1731-1734

Author(s):

Shao Hua Li ◽

Ge Wu ◽

Ling Zhang

Keyword(s):

Temperature Field ◽

Numerical Investigation ◽

Turbulence Intensity ◽

Film Cooling ◽

Leading Edge ◽

Cooling Efficiency ◽

Simulated Temperature

In order to investigate the influence of cooling efficiency of leading edge of film cooling blade with different turbulence intensity and blowing ratios,which use method of N-S equation,various blowing ratios of 1.0、1.5 and 2.0,various turbulence intensity of 5%、12%、20% and 30%,it simulated temperature field in leading edge of film cooling blade.The results show: cooling efficiency decreased when blowing ratios is increased.When turbulence intensity is 5%、12% and 20%,it obtains maximum cooling efficiency blowing ratios of 1.0.When turbulence intensity is 30%,it obtains maximum cooling efficiency blowing ratios of 1.5. In blowing ratios of 1.0,cooling efficiency decreased when turbulence increased.But in blowing ratios of 1.5 and 2.0,cooling efficiency increased when turbulence increased.

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Elliptic Airfoil Stall Analysis With Trailing Edge Slots

Volume 1: Advances in Aerospace Technology ◽

10.1115/imece2010-38606 ◽

2010 ◽

Author(s):

Jonathan Kweder ◽

Mary Ann Clarke ◽

James E. Smith

Keyword(s):

Lift Coefficient ◽

Leading Edge ◽

Surface Velocity ◽

Circulation Control ◽

West Virginia University ◽

Trailing Edge ◽

Near Surface ◽

Wind Speeds ◽

Edge Location ◽

Stall Angle

Circulation control (CC) is a high-lift methodology that can be used on a variety of aerodynamic applications. This technology has been in the research and development phase for over sixty years primarily for fixed wing aircraft where the early models were referred to as “blown flaps”. Circulation control works by increasing the near surface velocity of the airflow over the leading edge and/or trailing edge of a lifting surface This phenomenon keeps the boundary layer jet attached to the wing surface thus increasing the lift generated on the surface. The circulation control airflow adds energy to the lift force through conventional airfoil lift production and by altering the circulation of stream lines around the airfoil. For this study, a 10:1 aspect ratio elliptical airfoil with a chord length of 11.8 inches and a span of 31.5 inches was inserted into the West Virginia University Closed Loop Wind Tunnel and was tested at varying wind speeds (80, 100, and 120 feet per second), angle of attack (zero to sixteen degrees), and blowing coefficients, ranging from 0.0006 to 0.0127 depending on plenum pressure. By comparing the non-circulation controlled wing with the active circulation control data, a trend was found as to the influence of circulation control on the stall characteristics of the wing for trailing edge active control. For this specific case, when the circulation control is in use on the 10:1 elliptical airfoil, the stall angle decreased, from eight degrees to six degrees, while providing a 70% increase in lift coefficient. It should be noted that due to the trailing edge location of the circulation control exit jet, a “virtual” camber is created with the free stream air adding length to the overall airfoil. Due to this phenomena, the actual stall angle measured increased from eight degrees on the un-augmented airfoil, to a maximum of twelve degrees.

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