ESTIMATION OF AERODYNAMIC CHARACTERISTICS OF A LIGHT AIRCRAFT

Abstract

This paper presents the aerodynamic estimation carried out on a three-dimensional
aircraft model by conducting wind tunnel tests and Computational Fluid Dynamics (CFD)
simulation. The test model is a 15% scaled down from a two-seater light aircraft that is
closed to the Malaysian made SME MD3- I60 aircraft. This aircraft model has been tested
at two different low speed tunnels, namely at Universiti Teknologi Malays ia 's tunnel
(UTM-LS T) test section sized of 2.0 x 1.5 m', and at Institute Aerodynamic Research.
National Research Council of Canada (IAR-NRC) sized 3.0 x 2.0 n/ tunn el. The speed
during testing at UTM-LST and IAR-NRC tunnels was up to 70 m/s, which corresponds to
6
Reynolds Numb er of 1.3 x 10 . The longitudinal and lateral directional aerodynamic
characteristics of the aircraft such as coeffic ients ofpr essure. f orces (lift, drag and side
force) and moments (roll, pitch and yaw moment) had been experimentally measured
either using direct f orce measurement or pressure measurement method. The data
reduction meth ods included the strut suppo rt interf erence factor using dummy image and
the blockage correction had been app lied in this wind tunnel tests. On top of the
experimental study, simulation was also performed using a commercial CFD code,
FLUENT Experimental works at UTM-LST and IAR-NRC tunnel showed that the
aerodynamic characteristics ofthis light airc raft were ill good agreement with each other.
Simultaneously, the aerodynamic fo rces obtained p am the experimental works and CFD
simulations had been compared. The results proved that they were agr eeable especially at
a low angle of attack.