Nicholson Konrad Koukpaizan
(Advisor: Prof. Marilyn Smith]

will defend a doctoral thesis entitled,

Improved Techniques for Aerodynamic Flow Control Simulation with Fluidic Oscillators

On

Wednesday, May 6 at 11:00 a.m.
Bluejeans : https://bluejeans.com/777510155

Abstract
The need for improved performance, reduced drag, and more energy efficient rotary-wing and fixed-wing vehicles has motivated the aerospace community to design and implement various flow control techniques. Active Flow Control (AFC), specifically fluidic Active Flow control (FAFC) has been identified as one of key transformative technologies for the future generation of vertical lift vehicles. The global effectiveness of these techniques has been demonstrated in multiple scaled experiments, but the fundamental physics leading to the overall control is not yet fully understood. Simulations can aid to fill many of the gaps in experiments by resolving features that are difficult to measure and evaluate new designs, but they also have their challenges. This dissertation focuses on the development of computational techniques for a specific type of flow control technique: fluidic oscillators.

High-fidelity simulations were performed with an in-house Computational Fluid Dynamics (CFD) solver to characterize the physics of jet interaction fluidic oscillators and provide a basis for the development of improved boundary conditions that obviate the need to resolve the fluidic device interior. Furthermore, a wall-mounted model was designed computationally as part of this research. The model integrates an array of fluidic oscillators to assess their effectiveness in controlling the otherwise separated flow. Computations of the unactuated and actuated flows were correlated with experimental data for the first-order and second-order statistics, and the rich flow field provided by CFD permitted the assessment of the mechanisms governing the flow control. Finally, the new validated boundary condition model was leveraged to further explore the flow control design space and assess the effect of installation parameters such as jet orientation and spacing.

Committee

• Professor Marilyn J. Smith – School of Aerospace Engineering (advisor)
• Professor Ari Glezer – School of Mechanical Engineering
• Professor Stephen M. Ruffin – School of Aerospace Engineering
• Dr. David M. Schatzman – U.S. Army CCDC AvMC
• Ethan A. Romander – NASA Ames