Low-Reynolds Number Behavior of the Leading-Edge Suction Parameter at Low Pitch Rates

Application of moving surface boundary layer control technique has been confined to relatively high Reynolds numbers. The present paper reports a numerical study of application of the above flow technique in the ultra-low Reynolds number range. A two dimensional incompressible unstructured grid based Navier Stokes solver has been used for conducting the numerical studies. Moving surface has been applied at three different portions on the airfoil surface, firstly, in the form of a rotating leading edge portion of the airfoil, secondly, a continuous moving surface from leading edge of airfoil to 57% of the chord along the leeward surface of the airfoil and thirdly a continuous moving surface from leading edge to 97% of the chord along the leeward surface of the airfoil. All the moving surface configurations show improvement of aerodynamic performance of the airfoil through enhancement of lift and decrement of drag as compared to a fixed surface one

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Experimental and numerical study of laminar separation bubble formation on low Reynolds number airfoil with leading-edge tubercles

Journal of the Brazilian Society of Mechanical Sciences and Engineering ◽

10.1007/s40430-020-2229-2 ◽

2020 ◽

Vol 42 (4) ◽

Author(s):

B. K. Sreejith ◽

A. Sathyabhama

Keyword(s):

Reynolds Number ◽

Numerical Study ◽

Separation Bubble ◽

Low Reynolds Number ◽

Bubble Formation ◽

Leading Edge ◽

Laminar Separation Bubble ◽

Laminar Separation ◽

Low Reynolds ◽

Low Reynolds Number Airfoil

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A Study of a Modern Transonic Fan Rotor in a Low Reynolds Number Regime for a Small Turbofan Engine

Volume 6A: Turbomachinery ◽

10.1115/gt2013-95447 ◽

2013 ◽

Author(s):

Toyotaka Sonoda ◽

Rainer Schnell ◽

Toshiyuki Arima ◽

Giles Endicott ◽

Eberhard Nicke

Keyword(s):

Reynolds Number ◽

Low Reynolds Number ◽

Leading Edge ◽

Reynolds Numbers ◽

Small Scale ◽

Turbofan Engine ◽

Pressure Surface ◽

Low Reynolds ◽

High Reynolds ◽

Transonic Fan

In this paper, Reynolds effects on a modern transonic low-aspect-ratio fan rotor (Baseline) and the re-designed (optimized) rotor performance are presented with application to a small turbofan engine. The re-design has been done using an in-house numerical optimization system in Honda and the confirmation of the performance was carried out using DLR’s TRACE RANS stage code, assessed with respect to experimental data obtained from a small scale compressor rig in Honda. The baseline rotor performance is evaluated at two Reynolds number conditions, a high Reynolds condition (corresponding to a full engine scale size) and a low Reynolds number condition (corresponding to the small scale compressor rig size), using standard ISA conditions. The performance of the optimized rotor was evaluated at the low Reynolds number condition. The CFD results show significant discrepancies in the rotor efficiency (about 1% at cruise) between these two points due to the different Reynolds numbers. The optimized rotor’s efficiency is increased compared to the baseline. A unique negative curvature region close to the leading edge on the pressure surface of the optimized rotor is one of the reasons why the optimized rotor is superior to the baseline.

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