Improving Aerodynamic and aeroacoustic performance of the propeller by synchronic wavy tubercles

One of the effective methods in improving the performance of propellers is the use of tubercles on blades inspired by nature and the basis of passive flow control. In this research, the effectiveness of an innovative idea has been investigated from an aerodynamic aspect with computational fluid dynamics analysis and from aeroacoustic aspect with experimental testing. This idea has been studied by creating wavy simultaneous tubercles on leading and trailing edges with a wavelength of 6 mm and an amplitude range of 3 degrees in pitch direction from near the root to tip of the blade. Improvement of aerodynamic efficiency has been done by numerical simulation using the rotating reference frame method, and improvement of static aeroacoustic efficiency has been done with experimental tests resulting from the calibration of microphone sensors. Computational fluid analysis using the finite volume method based on finite elements and solving Reynolds averaged Navier-Stokes equation with K-Omega-SST model has been validated from reference experimental test. By studying the independence of results, the appropriate computing domain and grid for numerical simulation of flow has been determined. Results show an increase in aerodynamic efficiency of 7.5% in advance ratio equivalent to maximum efficiency and an increase of 22% in others. Reduction of maximum sound intensity in frequency equivalent to the main harmonic of the propeller, 1.4% in the area near the rotor plate and 3.8% in the area behind the plate, shows improvement of aeroacoustic performance.