Rotorcraft aerodynamics performance and stability

Faculty: Dr. Marcel Ilie, Dr. Mosefqur Rahman

Objectives: The effect of blade-vortex interaction (BVI) phenomenon, on the rotorcraft aeroacoustics and aerodynamics performance & stability, and active and passive flow control techniques to mitigate these effects, will be investigated computationally.

Intellectual Merit: The intellectual merit of the proposed research stems from the novelty of the method employed and the use of synthetic jets for flow control in rotorcraft applications. The proposed research will provide a better understanding of the BVI phenomenon and identify the factors affecting the BVI as well provide means of mitigating the BVI through active/passive flow control techniques. It is expected that the active flow control techniques, such as synthetic jets, would reduce sound level by 20dBA.

Preliminary Results: Computational results of BVI are shown in Figure 1 that presents the velocity field, at the instant of BVI, at the instant of BVI, from the LES computations, for a R_e=10⁶, based on the free-stream velocity and chord of the airfoil, [6]. The momentum equations were integrated in time using a second order hybrid scheme. Advection terms are calculated explicitly using a second order Adams–Bashforth while diffusion terms are calculated implicitly using second order Adams–Moulton to yield an approximate solution for the velocity field.

REU students’ educational outcomes: The REU student will be trained in the computational aerodynamics and aeroacoustics, using commercial CFD software, ANSYS-Fluent with the specific goal of developing computational skills, become familiar with the numerical schemes for space and time discretization, and ability to interpret the computational results. Through this research, the REU student will acquire knowledge in the fields of turbulence modeling, sub-grid scale modeling, specifically near-wall modeling which is an open problem in CFD, laminar-turbulent flow transition and boundary layer control. The students will also develop technical writing and presentation skills through research poster and a draft paper, which will contribute to conference and/or journal publications with the students as co-authors.