Open AccessINFLUENCE OF SURFACE ROUGHNESS ON THE DYNAMIC STALL OF A ROTARY WING SECTION IN SUBSONIC FLOW
Author(s) -
Farag Mahel Mohammed
Publication year - 2021
Publication title -
magallaẗ kulliyyaẗ al-rāfidayn al-ǧāmi'aẗ al-'ulūm/maǧallaẗ kulliyyaẗ al-rāfidayn al-ǧāmiʻaẗ li-l-ʻulūm
Language(s) - English
Resource type - Journals
eISSN - 2790-2293
pISSN - 1681-6870
DOI - 10.55562/jrucs.v22i1.493
Subject(s) - airfoil , pitching moment , stall (fluid mechanics) , angle of attack , lift coefficient , aerodynamic center , naca airfoil , mechanics , chord (peer to peer) , surface roughness , surface finish , aerodynamics , materials science , physics , reynolds number , computer science , composite material , turbulence , distributed computing
Wear involves the losses of some material from the surface and leads to the surface roughness. In the present work, the influence of surface roughness on the dynamic stall of a rotary wing section in subsonic flow has been investigated with different degree of surface roughness. The airfoil surface roughness was estimated using arithmetic mean roughness value (ISO-4287/1). For this purpose an indicial response method for unsteady, two dimensional flow is used to calculating the unsteady lift and pitching moment of NACA 0012 airfoil undergoing a pitching oscillation in the deep dynamic stall regime. Using the ANSYS-5.8 software as a source for the preliminary static data that required by the indicial method. The investigation is done through a number of test cases with different mean angles of attack, amplitude and reduced frequencies for airfoil oscillating around its quarter chord axis. The results include the time dependent behaviour and hysteresis loops of the lift and pitching moment for the airfoil with different degree of surface roughness. For rough airfoil an aerodynamic characteristic showed a reduction in the lift coefficient, separation point moved forward to the leading edge, the boundary layer reattachment take place at smaller angle of attack, the stall angle decrease and the pitching moment coefficient decrease as compared with smoother airfoil. So the periodic test must be done and re-coating the rotary wing if the surface roughness increased.