S. Mano1, S. Arunvinthan1, and S. Nadaraja Pillai This email address is being protected from spambots. You need JavaScript enabled to view it.1

1School of Mechanical Engineering, SASTRA Deemed University, Thanjavur, Tamil Nadu, India


 

Received: November 19, 2019
Accepted: February 28, 2020
Publication Date: December 1, 2020

Download Citation: ||https://doi.org/10.6180/jase.202012_23(4).0004  

ABSTRACT


In recent times, air transport has emerged as an important force in driving the globalization process, resulting in an ever increasing passenger growth, which in turn demands reduced in-between timings of preceding flights. One of the prominent factors which influence this in-between timings is the downstream wake characteristics. Therefore, in this current study, a series of wind tunnel investigations were performed to assess the downstream near wake characteristics of the NACA 0015 airfoil at various angles of attack corresponding to Re =1.83×105. The downstream near wake measurements and turbulence quantities were measured using a Pitot-static probe and a simultaneous pressure scanner, with a sampling frequency of 700Hz. Experimental results revealed the complex nature of the downstream near wake characteristics featuring substantial asymmetry arising out of the incoherent flow separations prevailing over the suction and the pressure side of the airfoil. Aiming at systematically investigating the downstream near wake characteristics, the following parameters like wake width, dissipation length, wake width coefficient, downstream velocity ratio and turbulence intensities were considered in this study. Based on the experimental results, it is found that the wake width and the downstream velocity ratio decreases with the increase in the angle of attack. However, the dissipation length, wake width coefficient and turbulence intensity increase with the increase in the angle of attack. Additionally, attempts were made to understand the physical nature of the near wake characteristics at two and four axial chord downstream locations.


Keywords: wake velocity; dissipation length; downstream velocity ratio; wake width coefficient


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