Gas Dynamics

The Keck CFD Lab has a three-prong research program: development of basic algorithms in computational fluid dynamics and related fields (computational aero-acoustics, electromagnetics, plasma physics and others); development of parallel codes to solve large-scale problems in aerodynamics and space physics; application of codes to physical problems. The staff consists of three faculty (Powell, Roe, Van Leer), two postdoctoral fellows, and over a dozen doctoral students. The physical facility includes a number of high-end workstations (HP and SGI) and peripheral equipment.

Research in the Laboratory for Turbulence & Combustion (LTC) conducted by graduate students, postdoctoral researchers, research scientists and faculty encompasses experimental, computational and theoretical studies of fluid dynamics, turbulent flows, combustion, and the development of advanced microsystems for flow and combustion applications. LTC includes a wide range of state-of-the-art facilities and equipment, including flow and combustion facilities, lasers, imaging systems, data acquisition systems, and computers. Our research page gives brief outlines of LTC research projects and publications that describe this work in more detail. Our facilities page gives a summary of some of the major experimental and computational facilities and equipment available in LTC.

Experimental and theoretical research is carried out on the development and application of electric propulsion systems, including electrothermal propulsion systems, electromagnetic propulsion systems, and electrostatic propulsion systems. The centerpiece of the laboratory is a large vacuum chamber that is 9 m in length and 6 m in diameter and is the largest vacuum facility of its kind at any university in the nation. A full range of measurement, instrumentation and data acquisition equipment supports the facility.

The research performed in the Propulsion and Turbulent Combustion Laboratory focuses on the fundamental structure of turbulent flames and their applications to propulsion. A variety of optical diagnostic techniques such as cinema particle image velocimetry (CPIV) and planar-induced laser fluorescence (PLIF) are used to gain insight into the structure of both subsonic and supersonic turbulent flames.

Structural Mechanics

Research into the fundamental aspects of mechanical behavior of composite structures is performed in the Composite Structures Laboratory. Experimental facilities include a biaxial planar four actuator servo controlled load frame, a blister testing facility, a shadow moire and holographic interferometry facility, a high speed camera (as fast as one frame per microsecond), a drop weight low impact facility, screw driven and table top loading frames and high speed data acquisition systems. Students have access to powerful work stations and requisite software. A recent effort is devoted to developing a microstructural based failure theory to account for all the possible modes of failure when advanced composite materials are stressed. Participants include Professors Anthony Waas, Peter Washabaugh, William Anderson, Victor Li (Civil), Alan Wineman (MEAM), and a number of graduate and undergraduate students.

The Composite Structures Laboratory was established in 1988 by the Department of Aerospace Engineering. Its activities involve research and training of graduate and undergraduate students in the Static and Dynamic Behavior of Structures made of Advanced Composite Materials. During the last decade, research projects have been funded by the NASA Langley Research Center, The ONR Mechanics Office, The AFOSR, The ARO and the NSF. In addition, funds have also been received from various industries, most notably the "big three" and its allied industrial partners. Most activities of the laboratory are conducted in the basement of the FXB Building and spans several laboratory rooms designed for different types of experiments.

Research
The main body of the research work is related to studying and developing viable theories to describe the failure mechanisms of composite materials and their structures. Recent projects have included a study of compression failure of curved ring type composite structures, biaxial compression failure of notched composite laminates, the response and failure of composite shells with cutouts subjected to axial compression, The collapse and energy absorption mechanisms of honeycomb cores and their panels, The crush behavior of composite tubes, Delamination buckling and growth of composite and sandwich panels, The fracture behavior of composite laminates and The high temperature response of notched composite laminates. The laboratory has several state-of-the-art servo hydraulic and screw driven loading frames, optical diagnostic capabilities including high speed analog and digital cameras, advanced high speed data acquisition systems, miniature loading frames and high accuracy, small capacity motion and load transducers etc.

Adaptive Materials and Structures Laboratory

The Adaptive Materials and Structures Laboratory has been dedicated to the fundamental research of thermo-mechanical coupled field effects in complex materials, especially shape memory alloys (SMAs) and elastomeric components at elevated temperatures.

The AMS laboratory is equipped with three general purpose testing machines: a 45-kip (200 kN) Instron uniaxial electromechanical testing machine with an environmental chamber and custom thermally-controlled grips for low rate testing of relatively stiff materials (metals and composites), a 3-kip axial/1300 in-lb torsion (13.4 kN) EnduraTec servo-pneumatic tension-torsion testing machine with a custom--built environmental chamber for moderate rate testing of soft materials (elastomers), and a 3-kip (13.4 kN) MTS uniaxial servo-hydraulic testing machine for higher rate testing of soft materials under simulated impact and cyclic loadings. Custom LabView-based data acquisition systems are available for each testing machine. In addition to air temperature chambers, a custom-built fixtures using thermoelectric devices and a fluid circulator bath (NESLAB RTE-220) are also available to provide more detailed temperature control during mechanical testing.

Thermal analysis equipment, including a differential scanning calorimeter (Perkin Elmer Pyris 1 DSC) are dynamic mechanical analyzer (Perkin Elmer DMA 7e), is available for accurate thermodynamic materials characterization. The DSC provides heat capacity and latent heat measurements. The DMA provides accurate dynamic and static measurement of thermomechanical properties of small, or low force, specimens.

Various optical imaging equipment (high resolution Nikon D2H, Nikon D100 and Princeton Instruments CCD cameras and high speed Kodak 1000HRC, 1000 frames/s CCD imaging system) and infrared imaging equipment (Inframetrics ThermaCam SC1000) are available for full-field deformation and temperature field measurements, respectively. The Inframetrics infrared radiometer and computer software allows full field images of temperature to be captured at 60 Hertz. The spatial resolution is a 256 x 256 pixel grid, and the temperature resolution is less than 0.1 °C. This allows temperature fields to be accurately measured and then post-processed as temperature color contours. This system has been used quite effectively in the past for the thermo-mechanical characterization of shape memory alloys that exhibit stress-induced exothermic (and endothermic) phase transformations.

A custom-built membrane inflation facility is available that can be used to perform experiments on pressurized thin membrane specimens, elastomers or thin film SMAs, at elevated temperature. Through the use of multiple CCD cameras, photogrammetry has been performed to measure to the non uniform multiaxial strain field on the surface of the membranes.

Current active participants include Prof. John Shaw (director), Prof. Alan Wineman (Mechanical Engineering), and Prof. David Grummon (Michigan State University). The laboratory equipment has also been used by professors in other departments, universities, and industrial sites for material characterization. The laboratory has been supported by grants from the National Science Foundation, the Department of Defense, and Sandia National Laboratory.

The Active Aeroelasticity and Structures Research Laboratory (A2SRL) is committed to advance the field of aerospace structures, particularly related to aerodynamic-structure-control and their interactions through research and education. A2SRL current research focuses on aeroelastic structures, active structures, and structural health monitoring applied to airplanes, helicopters, and reusable launch vehicles. A combination of theoretical, numerical, and experimental studies is conducted in especially dedicated experimental and computational facilities. A2SRL also houses a hover test stand facility specially design and built to test up to 10-ft diameter Mach-scale active helicopter rotors.

Flight Dynamics and Controls

Vibration, Acoustics, and Motion Control Laboratory

The Vibration, Acoustics, and Motion Control Laboratory provides facilities for conducting experiments in active feedback control. Research projects have include active noise control, control of structural vibration, and control of rotating imbalance. These experiments focus on the development of suitable hardware configurations for implementing feedback control algorithms, as well as robust, nonlinear, and adaptive control algorithms.Relevant equipment includes SRS, Scientific Atlantia, and Siglab spectrum analyzers for signal processing and system identification, dSPACE control boards for real-time controller implementation, and code generation software for controller implementation.

An electric 6DOF shaker table is used for motion control experiments. This table has 2000 lbf capacity, and is digitally controlled. A Polhemus sensor is used to measure 3-dimensional rotation and translation.

The Attitude Dynamics and Control Laboratory provides experimental facilities for research on the dynamics and control of complex attitude systems. The Laboratory is intended to contribute to theoretical and practical advances in spacecraft attitude dynamics and control problems. Two major experimental testbeds, the Air Spindle testbed and the Triaxial Attitude Control testbed, provide the core experimental facilities for the laboratory. These testbeds are the basis for a variety of research projects on attitude dynamics and control issues. Research topics include: modeling, analysis and simulation of 3D pendulums and multi-body systems; attitude sensing using gyroscopes, magnetometers, and optical methods; attitude actuation using fan thrusters, reaction wheels, and proof mass actuators; and attitude control using adaptive and nonlinear approaches. The laboratory contains computers, instrumentation, and other equipment that supports the various research investigations.