Mojtaba Ahmadi-Baloutaki, Ahmad Sedaghat, Mohsen Saghafian and Mohammad Ali Badri, A computational study on robust prediction of transition point over NACA0012 aerofoil surfaces from laminar to ..., THEORETICAL & APPLIED MECHANICS LETTERS 3, 042004 (2013)

A computational study on robust prediction of transition point over NACA0012 aerofoil surfaces from laminar to turbulent flows

 

Mojtaba Ahmadi-Baloutaki,1 Ahmad Sedaghat,2, a) Mohsen Saghafian,2 and Mohammad Ali Badri3

 

1)Department of Mechanical Engineering, University of Windsor, Ontario N9B 3P4, Canada

2)Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156, Iran

3)Research Institute for Subsea Science & Technology, Isfahan University of Technology, Isfahan 84156, Iran

 

(Received 14 May 2013; accepted 21 June 2013; published online 10 July 2013)

 

Abstract

Flow transition from laminar to turbulent is prerequisite to decide whereabouts to apply surface fow control techniques. This appears missing in a number of works in which the control eects were merely investigated without getting insight into alteration of transition position. The aim of this study is to capture the correct position of transition over NACA0012 aerofoil at dierent angles of attack. Firstly, an implicit, time marching, high resolution total variation diminishing (TVD) scheme was developed to solve the governing Navier{Stokes equations for compressible 

fuid fows around aerofoil sections to obtain velocity proles around the aerofoil surfaces. Secondly, the linear instability solver based on the Orr{Sommerfeld equations and the eN methods were developed to calculate the onset of transition over the aerofoil surfaces. For the flow subsonic Mach number of 0.16, the accuracy of the compressible solutions was assessed by some available experimental results of low speed incompressible fows. In all cases, transition positions were accurately predicted which shows applicability and superiority of the present work to be extended for higher Mach number compressible fows. Here, transition prediction methodology is described and the results of this

analysis without active flow control or separation are presented.

 

2013 The Chinese Society of Theoretical and Applied Mechanics. [doi:10.1063/2.1304204]

 

Keywords transition prediction, hydrodynamic stability, laminar flow control, TVD solver, aerofoil