Design and safety analysis of an in-flight, test airfoil

The evaluation of an in-flight airfoil model requires extensive analysis of a variety of structural systems. Determining the safety of the design is a unique task dependant on the aircraft, flight environment, and physical requirements of the airfoil. With some areas of aerodynamic research choosing to utilize flight testing over wind tunnels the need to design and certify safe and reliable designs is a necessity. Commercially available codes have routinely demonstrated an ability to simulate complex systems. The union of three-dimensional design software with finite element programs, such as SolidWorks and COSMOSWorks, allows for a streamlined approach to the iterative task of design and simulation. The iterative process is essential to the safety analysis of the system. Results from finite-element analysis are used to determine material selection and component dimensions. These changes, in turn, produce different stress profiles, which will affect other components. The unique case presented in this study outlines the process required to certify a large swept-wing model mounted to a Cessna O-2 aircraft. The process studies the affect of aerodynamic loading on the hard-point structure inside the wing, as well as the model mounting structure, and support strut. The process does not end when numerical simulations indicate that each system is safe. Following numerical work, a series of static tests are used to verify that no unforeseen failures will occur. Although the process is tailored to one specific example, it outlines an approach that could be applied to any test platform. A different model may create a physically different system, but the safety analysis would remain the same.