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Unsteady effects of camber on the aerodynamic characteristics of a thin aerofoil moving near the ground

Published online by Cambridge University Press:  04 July 2016

M. F. Zedan  and
A. O. Nuhait
M. F. Zedan
Affiliation:
Mechanical Engineering Department, College of Engineering, King Saud University, Riyadh, Saudi Arabia
A. O. Nuhait
Affiliation:
Mechanical Engineering Department, College of Engineering, King Saud University, Riyadh, Saudi Arabia
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Abstract

The effect of camber on the aerodynamic characteristics of an infinitely thin aerofoil approaching the ground is studied using a numerical model that accounts for the unsteady nature of the flow. The wake is computed as a part of the solution and the image technique is used to account for ground effects. The results indicate that relative deviations of lift and moment coefficients, from corresponding values far from ground, decrease as the camber ratio or angle of attack increases. Moving the location of maximum camber backward has a similar effect. Meanlines of NACA 4-digit series showed smaller deviations compared to NACA 6-digit series meanlines. Increasing camber ratio or moving maximum camber backward causes the wake trajectory to be lower. The steady ground-effect approach is inaccurate and may give erroneous results for plates with high camber ratios at small angles of attack, especially near the ground.

Type
Research Article
Information
The Aeronautical Journal , Volume 96 , Issue 959 , November 1992 , pp. 343 - 350
Copyright
Copyright © Royal Aeronautical Society 1992 

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