University of Notre Dame
The University of Notre Dame is active in numerous fields related to energy systems and turbomachinery. In 1999 the Center for Flow Physics and Control was established to promote multi- and inter-disciplinary research in the areas of flow diagnostics, prediction and control. There are 20 current faculty working in the following research focus areas:
MULTI-PHASE FLOWS. Current efforts include the dynamics of aerosol formation and characterization diagnostics, particle transport and deposition, liquid-metal magneto-hydrodynamic heat transfer, single and two-phase magneto-hydrodynamic flows, cavitation, combustion instabilities, non equilibrium rate chemistry, detonation theory, and ionized gases (plasmas).
FLUID STRUCTURE INTERACTIONS. The forced response of fluid loaded structures plays an important role in acoustics and high cycle fatigue. Current research involves the vibro-acoustic response of highly loaded structure (thin, lightweight materials), elastic shell theory, structural response to swirling flows, and potential disturbance propagation in high speed turbomachinery.
AERO-OPTICS. This group deals with the interaction of light with fluids. For example, when an otherwise collimated, coherent beam of light encounters a turbulent flow field that includes index-of-refraction fluctuations (density fluctuations in air at high Mach numbers), its optical wave front becomes aberrated, causing the beam to be degraded. The group focuses on theoretical and experimental research on understanding and modeling the wave front distortion for a laser propagating through turbulent, variable-index flows. This is an issue with airborne laser systems used for defense, and point-to-point data transmission.
ACOUSTICS. Current research activity involves sound generated from rotating blade rows, trailing edge sound, theoretical modeling of vortical sound production, acoustics of fluid-structure interactions, and high speed jet noise. The experimental efforts are conducted in two acoustic facilities: the Anechoic Wind Tunnel, and a blow-down type jet facility.
FLOW CONTROL. The active use of sensors and actuators into engineering fluid flows is an over-arching theme within all of the above areas of research. The objective is to add a minimal amount of energy to a flow to achieve a new flow field with a beneficial outcome. Often this takes the form of smartreal time processing that allows a device to react to varied boundary conditions. Current research involves trailing edge vectoring, airfoil separation control, tip clearance flow control, jet noise control, and stall/surge control. Of particular interest at Notre Dame is the development of plasma actuators. These devices use high voltage, low current electricity to create low level ionization of air to impart a body force in the fluid near a solid surface. These devices have been remarkably successful in reattaching separated flows, and aerodynamically blockingphysical gaps such as a tip clearance. Numerous new sensors and actuators are currently under development.
Areas of Interest
The specific areas of interest include experimental, computational (CFD), and theoretical applications related to flow control, acoustics, fluid-structure interactions, aero-optics, and multi-phase fluid dynamics.
Facility Information
The Center for Flow Physics and Control is located in the newly renovated Hessert Laboratory for Aerospace Research. This modern 40,000 sq. ft. building houses 12 faculty and approximately 30 graduate students and post-docs. The equipment available within the Hessert Lab includes the following.
HIGH SPEED COMPRESSOR. This 1.5 stage compressor is 18in in diameter, and powered at 15,000rpm using a 400hp DC motor. The core of the compressor was designed specifically for flow control and optical access. Design pressure ratio is 1.5.
TRANSONIC AND SUPERSONIC TUNNELS. These are indraft type tunnels that can operate continuously at supersonic conditions. They are often used for compressible shear layer studies, transonic cascade measurements, and supersonic nozzle flow. Test sections up to 25 sq. in. can be used to provide room for cascade blades or models.
LARGE SCALE CASCADE. This facility is currently outfitted with Pratt & Whitney PAK-B turbine blades with 5in chord and 2ft in span. The tunnels is used for separation control and tip clearance control measurements.
ANECHOIC WIND TUNNEL. The AWT has a working space of 20ft wide, 26ft. long and 8ft. high with fiberglass sound absorbing wedges on all six sides. This wedge configuration provides a low frequency cutoff of about 100 Hz. Above the cutoff frequency; the wedges have a coefficient of energy absorption at normal incidence of 0.99 or greater. A low turbulence subsonic free-jet/ closed test section wind tunnel has been developed to fit into this anechoic chamber for aerodynamic measurements and sound pressure level and sound intensity measurements generated from propellers, fans, pumps, airfoil configurations, etc. The cross-sectional area of the test region is four square feet (0.37 square meters) with a maximum velocity of about 100 feet/second (30.5 meters/second). This wind tunnel has been designed so that it can be removed to accommodate other acoustic experiments. Current research has applications for aircraft as well as automotive and marine vehicles.
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