Rotorcraft Aerodynamics and Aeroacoustics

Blade-Vortex Interaction
Vortices generated by the leading blade interact with the following blade, resulting in a strong fluctuation in the airload. Vibrations and aerodynamic noise are also generated as a result of the blade-vortex interaction (BVI).  From the viewpoint of rotorcraft design, BVI, which affects various fields, is a very crucial physical phenomenon. The problem is that since the vortex is numerically highly dissipative, to predict BVI accurately, a large number of grids is necessary, resulting in an excessive computing load. The eMLP-VC scheme designed to target vorticity conservation was used to predict this phenomenon. Noise prediction due to BVI was also carried out.

Propeller-Wing Interaction
The wake of the propeller make the airloads of the wings fluctuate, causing aerodynamic noise and vibration. In addition to the propeller, the wing also has an effect on the propeller.
With the use of a high-accuracy scheme, the interaction between propellers was examined, as well as the influence of the number of propellers and rotation direction.

Prediction of Aerodynamic and Aeroacoustic Characteristics Using ROM
with Mr. Soonmoung Kwon and Mr. Yu-eop Kang (Ph.D students in SNU AVDL)
Thanks to their ability to take off and land vertically, rotorcraft are frequently operated in close proximity to residential areas. However, helicopters are extremely susceptible to aeroacoustic noise, and in particular, noise generated by BVI propagates downward to the aircraft, limiting helicopter operations in cities. As a result, our research team selected the helicopter's take-off and landing path based on an approximate model approach with a Reduced Order Model (ROM). This approach is possible to predict aerodynamic noise accurately by utilizing the URANS-based dataset.