Low-speed flows involving bubble separations

Numerical simulation of flow over an airfoil for small wind turbines using the $$\gamma - {\text{Re}}_{\theta }$$ γ - Re θ model

“…Further contributions in the characterization of LSB were made by McGregor [29], Young and Horton [30] and Woodward [31]. Further, extensive literature on LSB and low Reynolds aerodynamics was documented by Carmichael [20], Lissaman [25] and Tani [32].…”

“…Here it is to emphasize that the size and position of the LSB are the functions of the airfoil shape, angle of attack (a), Re and environmental interruptions [28,32].…”

Prediction of Aerodynamic Characteristics for Elliptic Airfoils in Unmanned Aerial Vehicle Applications

“…This must be due to the size of separation bubble produced in that region. As first explained by Tani (1964) and later reviewed by Shyy et al (1999) and Lian & Shyy (2007), long separation bubbles generally cover considerable portion of airfoil surface and affect inviscid pressure and velocity distributions around the airfoil, whereas, short bubbles cover small portion of surface and do not affect pressure and velocity distributions.…”

“…Depending on the size of bubble, LSB's are typically categorized as either short or long bubbles (Tani, 1964). A long bubble occupies a significant portion of the airfoil surface and affects the inviscid pressure and velocity distributions over much of the airfoil, whereas a short bubble covers only a small portion of airfoil surface and does not affect the pressure and velocity distributions.…”

Flow-Control Effectiveness of Convergent Surface Indentations on an Aerofoil at Low Reynolds Numbers

“…Therefore, a long bubble significantly limits the aerofoil's lift and increases the pressure drag. 4,9 Moreover, although short separation bubbles have been experimentally shown to have little effect upon the aerofoil's lift, they can create a thicker turbulent boundary layer that results in a significant drag increase. 6 Therefore, the primary goal of flow control at low Re is to reduce or eliminate the separation bubble in order to increase lift and reduce drag.…”