Design and Numerical Optimization of Thick Airfoils Including Blunt Trailing Edges

The numerical optimization of thick airfoils by means of genetic- and gradient-based numerical optimization in combination with a Navier-Stokes code is described and the results are discussed. The objectives of the study are to maximize both the section moment of inertia, and the airfoil lift-to-drag ratio at fully turbulent conditions and a chord Reynolds number of 1 x 10... A robust and flexible airfoil surface definition that is based on polynomial functions and allows for blunt trailing edges is used to generate section shapes with a maximum-thickness-to-chord ratio between 35 and 42%. To mitigate the unsteady vortex shedding, a splitter plate is added to the blunt trailing edge of the resulting airfoils. This allows steady-state simulations with the Navier-Stokes code and reduces the calculation time. The study resulted in a Pareto front, which represents a range of aerodynamically and structurally improved airfoils. Although the optimizer was given the opportunity to create airfoils with a nominally sharp trailing edge, the improved airfoils all contain significant trailing-edge thickness. (ProQuest Information and Learning: ... denotes formulae/symbols omitted.)