Aerodynamic Optimization of High Speed Propellers

Gonzalo Montero Villar (Chalmers University)

CHALLENGE - The fact that fuel costs accounts for 29% of all airlines cost and the increase in environmental awareness is driving the aviation industry to reach for more efficient engines. One of the promising technologies to tackle this problem is the open-rotor, or more specifically, counter rotating open-rotors (CROR), which are expected to bring fuel savings to 20% − 35%. A new type of propeller blade concept is the Boxprop. Its highly 3 dimensional geometry together with the complexity of the flow, make optimization challenging for conventional design methods, thus necessitating a different approach.

SOLUTION - This work presents an optimization framework, a geometric parametrization, geometry creation and mesh generation approach in order to optimize the Boxprop by means of genetic algorithms. As far as the genetic algorithm is concerned, it has been tested and compared with the optimization software modeFRONTIER. During the optimization process multiple blade designs are evaluated, requiring an automated mesh generation. This automation is carried out by means of ICEM CFD scripting, which allows a fast and parametrized mesh generation.

BENEFITS - The parametrization chosen for the Boxblade, despite some limitations, seems to give enough design freedom in order to be considered for the optimization. Moreover, the geometry generation method where STL surfaces are generated from a cloud of points in Python has been shown useful and versatile. Also, the testing of the implemented genetic algorithm has given good results and the framework has been tested and the implementation can be considered as satisfactory.