Research or Creative Experience for Undergraduates (RCEU) Projects - May 2019 - August 2019
Wind tunnel model (above) and symmetric actuation effects at 12kV (below)
Selective Dielectric Barrier Discharge Actuation for Flow Control of Delta Wings
The goal of the proposed project was to control the vortex formation over a delta wing surface, using selective Dielectric Barrier Discharge (DBD) actuation to improve the aircraft’s performance. DBDs or plasma actuators are electrical devices that generate a wall bounded jet without the use of any moving parts. In contrast to conventional DBD actuators driven by sinusoidal voltages, a voltage profile consisting of nanosecond pulses superimposed on dc bias voltage is proposed. The advantage of this non self-sustained discharge is that the parameters of ionizing pulses and the driving bias voltage can be varied independently, which adds flexibility to control and optimization of the actuators performance. The proposed work investigated the possibility of selectively manipulating vortex formation using nanosecond DBD’s over a delta wing to improve aircraft’s performance. Wind tunnel testing and flow visualization techniques such as Particle Image Velocimetry was used for evaluating the DBD’s efficiency. Effects of symmetric leading-edge DBD actuation in a post breakdown phase at x/c=0.5 shows a reduced region of increased peak vorticity for the right vortex along with the substantial strengthening of the left vortex which led to the reformation of the vortex core, consequently delaying vortex breakdown.
Optimized blended and multi-winglet (above), Lift/Drag Coefficient vs Angle of Attack for different cant angles (below)
Preliminary Analysis & Design of Morphing Winglets for UAVs
The goal of the proposed work was to conduct an analysis and develop a morphing (adaptive) multi-winglet capable of reducing the strength and size of wingtip vortices, resulting in improved aircraft performance. Induced drag accounts for roughly 40% of the total drag on an aircraft and therefore, reduction of the induced drag would significantly reduce fuel consumption, cost of operation, and the carbon footprint of the aircraft. Wingtip modifications can either move the vortices away in relation to the aircraft longitudinal axis or reduce their intensity. Morphing multi-winglets, where the geometry can be adjusted real-time to the changing flow conditions, have the potential to improve the aerodynamic performance during climb and/or high-speed off-design conditions by providing adapted wing lift distribution throughout the flight envelope. The developed adaptive winglet designs will subsequently be subjected to wind tunnel testing and Particle Image Velocimetry for optimization and performance analysis.
New Faculty Research (NFR) Program - December 2018 - December 2019
Morphing wing prototype and CAD (above), Flexinol actuator test setup (below)
Design and Development of an Actuation System for Morphing Wings
The goal of the proposed work is to design and develop a lightweight actuation system for a morphing flap capable of sustaining a smooth operation under aerodynamic loads. Using a morphing (adaptive) wing, whose geometry varies according to changing external aerodynamic loads, the airflow in each part of the aircraft mission profile can be optimized, resulting in an increase of aerodynamic efficiency during flight. The use of additive manufacturing techniques enables manufacturing parts with selective strength, toughness, and ductility by linking multiple types of topologies in the case of “lattice structures”. This, not only introduces a new degree of design freedom to build morphing structures with identical geometry but also allows it to bend in different ways. A morphing flap using shape memory alloy (SMA) actuators will be designed, developed and tested, while actuation optimization will be conducted through Particle Image Velocimetry analysis and wind tunnel tests.