EXPERIMENTS AND SIMULATIONS

ECTS credits: 2

Objectives:

Airfoil Mechanics studies wing torsion as the wing incidence greatly affects performance (in terms of lift and drag). The project involves building a wing using (very) precise truss ribs and two longerons. Torsional stiffness is measured at several stages during the construction process. Stiffness with only the longerons, adding the shear webbing, leading edge, trailing edge and covering.

Parallel to the construction and measurements, the students calculate the torsional stiffness of the wing using RDM6

Finally, the wing characteristics (lift and drag versus incidence angle) are analyzed using the XFOIL software.

As torsional stiffness of the wing depends on elements with complex shapes, the students build a balsa bridge in parallel, with a limited amount of balsa 5x5mm sticks. The bridge should resist the highest load, but should also have the highest (torsional) stiffness. The students analyze the elements that endure the highest stress using RDM6 and optimize the structure. The students should predict this highest load and stiffness numerically, and compare the result with the measured values. The bridges are finally loaded to establish the maximum load and the type of catastrophic failure.

The general objectives of this course are:

a) help students identify the most loaded elements in a structure;

b) optimize the structure such that each element is equally loaded; 

c) optimize a structure with respect to two (conflicting) requirements (flexion and torsion); 

d) study airfoil drag and lift forces for various angles of attack;

Syllabus:

          1 – Wing construction

• Samba truss rib construction,
• Ribs on longerons,
• Shear webbing,
• Leading edge
• Trailing edge
•  Covering

          2 – Bridge construction:

• Optimization wrt flexion (RDM6)
• Optimization wrt torsion (RDM6)
• Final construction and testing

          3 – Wing characteristic analysis with XFOIL

          4 – Final presentation