Effects of the Wake Turbulence on Aircraft Wing Model: Experimental Method

A research on studying the effect ofthe wake generated by an aircraft wing section on a
following aircraft wing section is performed. NACA 2412 is chosen as the airfoil model
in this project. The airfoil model is fabricated by using CNC machining. Aluminium is
chosen as the material for the airfoil model because it provides a good surface finish.
Three experiments are conducted by using the open-circuit wind tunnel in Universiti
Sains Malaysia (USM). The wind tunnel tests were carried out at the velocity of 5m/s to
30m/s in a test section of the size 0.30m (W), 0.30m (H) and 0.60m (L), at the Reynolds
number of4.10 x 104 to 2.54 x 105. Experiment 1 isthe testing of single airfoil model to
define the coefficientoflift, coefficient of drag and Reynoldsnumber at various angles of
attack. Experiment 1 is functioning as references for comparison for Experiment 2 and
Experiment 3. Experiment 2 and Experiment 3 are the testing of two airfoil models at a
separating distance of 1 chord length (13cm) and 2 Chord lengths (26cm) respectively.
The main objective of Experiment 2 and Experiment 3 are to study the effects of wake
turbulence on the characteristic of coefficient of lift, coefficient of drag and Reynolds
number of a following airfoil model when an airfoil model is placed in front of it at a
specific distance. The characteristics of the wake generated by an airfoil model on a
following airfoil model are observed and studied during the testing in wind tunnel.
Further investigations, discussions and conclusions are carried out throughout completing
this research project. The results show that the separating distance between the two
airfoils affects the coefficient of lift, coefficient of drag and the stall angle of the
following airfoil at various angle of attack and free stream velocity.