Download Fathi Finaish Broad Areas of Research Interests: Aerodynamics

Fathi Finaish
Broad Areas of Research Interests: Aerodynamics/Fluid Dynamics
Specific Research Interests: Aerodynamic testing, unsteady flows, vortex dynamics in separated flows,
physical and numerical flow visualizations, active flow control, and flow mixing.
Areas of Teaching Responsibility: Aerodynamics, fluid dynamics, design, and experimental methods.
Description of Scholarly Expertise:
External Flows: A variety of factors have led to a surge in present interest in low Reynolds number
aerodynamics. For instance, recent interest in renewable energy has resulted in growing interest in wind
turbines and related technologies. Recent advancements in the fields of micro-system technology have
enabled the development of mini- and micro aerial vehicles, which have a broad range of potential
applications. The development of aircraft on such a small scale has led to a variety of previously rarely
encountered low Reynolds number phenomena, such as Laminar Separation Bubbles (LSB). Our current
efforts are focused on investigating the feasibility of employing plasma actuators as a means of
controlling LSB. Both steady and unsteady plasma actuation modes are being investigated. In our recent
efforts, a plasma actuator, modeled as a localized body force, is applied to the airfoil surface, and used to
effect changes in the characteristics of the bubble and the airfoil aerodynamic performance. Parametric
studies are conducted for both the steady and pulsed actuator configuration to determine the optimal
configurations of the actuator in each case. The pulsed and steady control methods are compared to
determine the advantages gained by pulsing the actuator. Additionally, power and voltage requirements
of the plasma actuator are estimated in order to gauge the practicality and effectiveness of the proposed
LSB control method.
Internal Flows: Poor mixing between the warm return air and the cold outside air often leads to air
stratification in Air Handling Units, which results in various problems, such as, nuisance trips of low
temperature safety thermostats, freezing of chilled or hot water coils in a stratified subfreezing air stream
and loss of control when sensors cannot read the true temperature of the air stream. Our most recent
efforts are focusing on quantifying mixing characteristics such as thermal statistic and range mixing
effectiveness and investigating the influence of flow baffles on flow mixing and produced pressure drop.
Laboratory Location: 334 Toomey
Laboratory Description: This laboratory houses an 18"x18" subsonic wind tunnel. This tunnel is an
open return type capable of producing flow speeds up to 90 mph in an 18"x18" square test section. Flow
turbulence is controlled by a combination of three anti-turbulence screens and honeycomb panel installed
in the tunnel-settling chamber. The tunnel is equipped with three interchangeable test sections that can
easily be installed downstream of a 6.25:1 contraction. Test models, a lighting system, and a movie
camera are available and can be employed to visualize flow developments over various test models.
Also, this laboratory houses a 10”x10" subsonic wind tunnel. This tunnel is a variable density wind tunnel
used for flow testing under controlled conditions of flow temperature, pressure, and humidity. This facility
is designed to test performance of airflow instruments as well as aerodynamic performance of models in
variable density environments. Heating, cooling, humidification arrangements, along with measuring
instruments are incorporated into the tunnel to provide for accurate control and monitoring of flow
properties. The tunnel is equipped with a 10"x10" test section where the static absolute pressure,
temperature, and humidity can be varied in ranges between 5-20 psia (34-137 kPa), 50-250oF (10121oC), and 0.003-0.012 lbv/lba (kgv/kga) respectively. The tunnel is equipped with an arrangement
suitable for generating a second flow for investigating flow mixing of air streams with dissimilar
temperatures and flow velocities.