Numerical Analysis of Effect of Leading-Edge Rotating Cylinder on NACA0021 Symmetric Airfoil

M A Taher Ali,Md Abdus Salam,Nafiz Ahmed Khan,Vikram Deshpande

doi:10.24018/ejers.2019.4.7.1385

M A Taher Ali, Md Abdus Salam + Show 2 more

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https://doi.org/10.24018/ejers.2019.4.7.1385

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Abstract

The moving surface boundary control (MSBC) has been a Centre stage study for last 2-3 decades. The preliminary aim of the study was to ascertain whether the concept can improve the airfoil characteristics. Number of experimental and numerical studies pointed out that the MSBC can superiorly enhance the airfoil performance albeit for higher velocity ratios (i.e. cylinder tangential velocity to free stream velocity). Although abundant research has been undertaken in this area on different airfoil performances but no attempt was seen to study effect of MSBC on NACA0021 airfoil for and also effects of lower velocity ratios. Thus, present paper focusses on numerical study of modified NACA 0021 airfoil with leading edge rotating cylinder for velocity ratios (i.e.) between 1 to 1.78 at different angles of attack. The numerical study indicates that the modified airfoil possess better aerodynamic performance than the base airfoil even at lower velocity ratios (i.e. for velocity ratios 0.356 and beyond). The study also focusses on reason for improvement in aerodynamic performance by close look at various parameters.

Highlights

In the beginning of 20th century, Prandtl predicted the boundary layer in the vicinity of the solid bodies
A thorough parametric analysis is undertaken wherein effect of the leading-edge rotating cylinder for a modified NACA0021 airfoil is undertaken at Reynolds number 250000 for different angles of attack from 0 to 20o
The data of coefficient of lift and coefficient of drag for the base NACA0021 airfoil is compared with the cl and cd of the modified airfoil for different velocity ratios ( )

Summary

Introduction

In the beginning of 20th century, Prandtl predicted the boundary layer in the vicinity of the solid bodies. Since scientific community is in the hunt ways and means to nullify the effects of boundary layer. A vast amount of data has been generated since beginning of 20th century. One of the very interesting flow control mechanism i.e. moving surface boundary layer control. This concept was first used by Anton Flettner for propulsion of an experimental rotor vessel in year 1924 [1]. This concept was successful for moderate to strong wings

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