Mechanical and Aerospace Engineering
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Computational Support for NASA Flight Test Operations
In cooperation with researchers at NASA Dryden Flight Research Center, an effort is underway in predicting aeroelastic behavior of arbitrary aircraft configurations. Computational Fluid Dynamic (CFD) solutions are coupled together with structural motion equations in order to predict aeroelastic and aeroservoelastic effects over a wide range of Mach numbers from subsonic to hypersonic speeds. Of particular interest is the ability to predict aeroelastic flutter boundaries in a time-efficient manner on workstation computers in order to support NASA flight-test operations.
Sponsors: NASA Dryden Flight Research Center and Oklahoma State Regents for Higher Education
PI: Andrew S. Arena, Jr.
RAs: Clint Fisher and Peter Jahns
Optimal Design/Testing Techniques for Automotive Air Filters/Filtration
Research is being conducted with the goals of improving the reliability of automotive air filter performance tests and providing detailed information on filter behavior that can be applied to develop optimized filter designs. This work is directed at improving both engine and cabin air filtration. Flow and particle distributions are being measured with a state-of-the-art two-component Laser Doppler Velocimeter (LDV) for air filters that are currently used in automobiles. Computer code predictions of filter performance are being compared with the LDV measurements. Measurements are being taken on pleated filters, both clean and dust laden, and on the flat filter media used to manufacture pleated filters. Measurements have been made with the filters tested in laboratory housings and in models of automotive engine housings. The laboratory housings provide filter performance under highly controlled conditions, but they do not necessarily represent performance under actual installed conditions within the automobile. The next phase of this research will address both predictions and measurements on clean and dust-laden filters in models of automotive engine and cabin housings. These predictions and measurements of filter performance will be used to develop innovative filters and vehicle filter housing designs that are optimized for vehicle operating conditions.
Sponsors: Purolator Products, Inc. and Oklahoma Center for the Advancement of Science and Technology (Applied Research)
PIs: Frank W. Chambers and Ronald L. Dougherty
RAs: Rob Duran, Wayne Gimlin, Moghad Jadbabaei, Faqiu Liang, G. Liu, Balasubramanian Natarajan, Rob Newman, Charles Tebbutt, Ye Tian, Jeff Williams, and Shenghong Yao
Correlation Transfer Applied to Industrial Suspensions
This project is directed toward the accurate sizing of small particles (0.00005 to 0.1 millimeter) that are suspended in a liquid. Many industries either produce a final product that is a mixture of very small particles and a liquid, or such a mixture is used at some point in the manufacturing process. Examples of these types of industries are: pharmaceuticalsÑhaving small particles suspended in a liquid wherein in the particle size must be carefully controlled in order to provide the correct dosage; and magnetic diskette productionÑhaving a mixture of particles in a liquid that, when dried, becomes the diskette material, requiring accurate particle size in order to achieve proper diskette quality. This project's purpose is to develop the theoretical and experimental means for determining the size(s) of such particles in suspensions, which may range from high particle concentrations to low particle concentrations. A non-intrusive laser-based method, called correlation transfer, is being explored for its potential to measure these particle sizes without interrupting the manufacturing process. The benefit of such a method would be the capability to assess and control the quality of the product without slowing or stopping the process. In the work to date, samples of small spheres in distilled water are illuminated by a laser beam. The light scattered back from the samples and the light transmitted through the samples is collected by photodetectors. The photodetector signals are processed by computer, and the results are compared to the theory for scattering and transmission in order to determine the sizes of the spheres. Variables that have been addressed to this point include the concentration of the spheres, diameter of the spheres, thickness of the samples, polarization of the laser beam, and refractive index effects.
Sponsor: Oklahoma Center for the Advancement of Science and Technology (Applied Research)
PIs: Ronald L. Dougherty
Bruce J. Ackerson (College of Arts and Sciences)
RAs: Steve Liu and Ulf Nobbmann
Correlation Transfer: A New Technique for Characterizing Dense Liquid/Particle Suspensions
Non-intrusive laser light scattering is being used to probe dense suspensions of particles within fluids. This collaborative research effort between Mechanical and Aerospace Engineering and Physics is studying the influence of particle size, particle density, particle scattering characteristics, and laser polarization. Results of this project could lead to quick, simple determination of the characteristics of particles within suspensions such as paints, gels, and drilling fluids--without disturbing the fluids. Specifically, the investigation is focused on the use of fiber-optic cable to facilitate in situ measurements.
Sponsor: National Science Foundation
PIs: Ronald L. Dougherty
Bruce J. Ackerson (College of Arts and Sciences)
RAs: Farhad Dorri-Nowkoorani, Ulf Nobbmann, Naffa Reguigui, and Steve Liu
Hydraulic and Thermal Performance Tests on a High Flux Heat Exchanger with PAO as the Coolant
Advances in high-power electronics in the aerospace industry have placed challenging demands on the design of thermal control systems. A novel High Flux Heat Exchanger (HFHE), to handle high heat loads generated by future military avionics systems, has been designed and fabricated by McDonnell Douglas Aerospace and Sundstrand Aerospace for the Air Force. The HFHE was developed based on the Compact High Intensity Cooler (CHIC) concept. The goal of this project is to conduct extensive performance (hydraulic/thermal) tests on the HFHE under different operating conditions with polyalphaolefin (PAO) as the liquid coolant. The final outcome of this study will demonstrate the heat load removal capability of the HFHE and will provide guidance for proper selection of the HFHEÕs practical operating conditions.
Sponsor: Wright Patterson Air Force Base, Ohio
PI: Afshin J. Ghajar
RA: Mike J. Cutbirth
Improved Manufacture of Tapered Tubes for Light Poles
Tapered metal tubes are used as the support for outdoor commercial lighting, special utility lines, and signage. These tubes are usually formed from a relatively thin steel plate into the form of a slender cone. Two methods are currently used to fabricate these tapered tubes. The most common is the use of a brake-press to form a many-faceted truncated cone. The second method is that of forming a flat metal blank around a solid conical mandrel. Both of these methods are slow and expensive. The length of these poles may range from 20-50 feet, but all of them have a taper of 0.14 inch of diameter per foot of length. Hence, a pole 50 feet in length might have a diameter of four inches at the top end and a diameter of 11 inches at the bottom. The object of this project is to develop a new process for forming tapered tubes that will be faster and less costly than existing processes. If a better process for bending flat metal blanks into conical sections can be developed, a large potential market, estimated at $65 million per year in sales for 1994, can be tapped.
Sponsors: Oklahoma Center for the Advancement of Science and Technology (Applied Research) and U.S. Department of Energy
PIs: Lawrence L. Hoberock and Richard L. Lowery
RAs: Jeff Adair, Richard Parkinson, Srinagesh Rao, Patrick Straughn, Robert Chada, Steven Brandon, Lonny Powers, and Jim Hartwig
Float Polishing of Ceramic Balls with Magnetic Fluids
Advanced ceramics are being considered for many applications including bearings and structural members. However, ceramics are hard, brittle, and extremely difficult to process into useful shapes. Magnetic float polishing is a new technology introduced by Japanese researchers for finishing ceramics. The magnetic float polishing technique is based on the ferrohydrodynamic behavior of a magnetic fluid that levitates balls, abrasives, and a float pad. Because the levitational force is proportional to the field gradient, the polishing load can be easily controlled. The float polishing technique offers great potential for the finishing of these materials with high finish and accuracy. It can be an extremely cost-effective and a viable method for the superfinishing of brittle materials with flat and spherical shapes. In magnetic float polishing, a strong eletromagnet is located under a container. A magnetic fluid (Fe304) is inside the container with fine abrasive particles and ceramic balls. The ceramic balls are located between the top plate and the float pad. When a magnetic field is applied, the ceramic balls, abrasive grains, and the float, all made of a non-magnetic material, are pushed upwards by the magnetic buoyant force. The ceramic balls are pressed against the float pad and are finished by the rotation of the polishing pad.
The objectives of the project are: to develop cost-effective technologies for polishing ceramic materials with improved surface quality and accuracy, to model and demonstrate float polishing process for this application and to optimize polishing parameters, to contribute towards the understanding of material removal mechanisms in hard and brittle materials, and to transfer this technology to industry in and around Oklahoma.
Sponsors: Advanced Research Projects Agency and Oklahoma State Regents for Higher Education
PIs: Ranga Komanduri and N. Umehara
RAs: Hauzen Bing, Matthew Dock, and M. Raghunandan
In Situ Machining and Scratching Inside the Scanning Electron Microscope
In ultra precision machining (i.e., submicron machining) the advances in machine tool performance have reached a stage where the current fundamental understanding of the tool work-material interactions may be the limiting factor for further advances in dimensional accuracy, surface finish, and metallurgical integrity of the part produced. There is still a dearth of both theoretical and experimental studies regarding the process mechanics. Conducting in situ submicron machining and scratching studies inside a scanning electron microscope facilitates the determination of the effect of cut depth, crystal orientation of different work materials, rake angle, and edge radius of the cutting tool on the machining performance. Plastic deformation in the primary and secondary shear zones, friction at the chip-tool interface, friction between the machined surface and the clearance face, and dynamic observation of the shear zone can provide valuable information in the understanding of the mechanics of the process. The objectives of this project are: to design, fabricate, and assemble the apparatus; to conduct machining experiments at the submicron level in order to study the effect of different variables including the depth of cut, cutting speed, rake angle, edge radius, and crystal orientation of different work materials (single and polycrystalline); to conduct a dynamic investigation of the primary and secondary shear zones as well as the zone in between the tool clearance face and the machined surface and/or as a consequence of the elastic recovery of the machined surface; to record the machining process on video tape for postmortem study of the process; to record the forces involved in the process by using a three component piezo electric dynamometer; and to study the "size effect," namely, effect of depth of cut on specific energy.
Sponsors: National Science Foundation and Oklahoma State Regents for Higher Education
PI: Ranga Komanduri
RAs: Ravi P. Seeralan and Sanjai Keshavan
Low Pressure Diamond Synthesis Using an Oxy-Acetylene Welding Torch
Combustion synthesis of diamond is a relatively new process pioneered in Japan in 1988. The process is simple, inexpensive, and utilizes an oxy-acetylene torch yielding high growth rates (30-150 mm/hr.). Other activated chemical vapor deposition (CVD) techniques, such as microwave CVD and hot filament CVD, yield growth rates of about 1 mm/hr. Combustion synthesis has high potential for commercial implementation in optical, electronic, and manufacturing applications. The objectives of this project are: to make improvement in the design and use of apparatus and related instrumentation; to conduct parametric studies varying substrate temperature, distance from the substrate to the inner cone, gas ratio, gas flow rates, and gas pressure for diamond films and coatings on cutting tools; to optimize conditions for high growth rate and/or high purity films; to study the nucleation and growth of diamond films; to study the effects of using a vacuum chamber to grow films at varying pressures and inert atmospheres; to develop this technology for application of diamond coatings on cutting tools; to develop new applications for this deposition technique; and to apply this technology to industry in and around Oklahoma.
Sponsors: National Science Foundation and Oklahoma State Regents for Higher Education
PI: Ranga Komanduri
RAs: Srihari Nandyal, Rober Stewart, and David Stokes
Magnetic Abrasive Finishing of Ceramic Rollers
The objectives of this project are: to design and construct a magnetic abrasive finishing equipment for the polishing of ceramic rollers; to develop cost effective and time effective manufacturing techniques specifically for polishing ceramic rollers with high surface finish and accuracy; to model and demonstrate the magnetic abrasive finishing process for this application and optimize finishing parameters; to contribute towards the fundamental understanding of the material removal mechanisms involved in the ceramic machining process; and to develop various applications of magnetic abrasive finishing for industry.
Sponsor: Advanced Research Projects Agency
PI: Ranga Komanduri
RAs: Michael Fox and Kishore Agrawal
Microwave Activated CVD Diamond and C-BN Synthesis
Microwave activated chemical vapor deposition (CVD) diamond synthesis has proven to be a reliable method of low pressure diamond synthesis. Though the growth rates are low (1mm/hr.), the method is very reliable with the ability to coat large surface areas (4 in.). The high quality uniform films have potential for electronic and optical applications. A comparable low pressure technique for the deposition of cubic boron nitride (C-BN) has not been developed with the same extent of reliability and consistency as CVD diamond. C-BN films have considerable potential application in the semiconducting materials area. The objectives of the project are: to develop good quality microwave CVD diamond films for optical and electronic applications; to develop a strong adherent coating of diamond on cemented tungsten carbide cutting tools and wear parts; to develop a reliable method to synthesize C-BN by microwave activated CVD; and to study in situ nucleation and growth of CVD diamond in an Environmental Scanning Electron Microscope.
Sponsors: National Science Foundation, Oklahoma Center for Integrated Design and Manufacturing, and Oklahoma State Regents for Higher Education
PI: Ranga Komanduri
RAs: T. Rama Mohan, Johnnie Hixson, Sujatha Tuengar, and K. Malika
Energy Dissipation in Ultra-Precision Machining
This work is aimed at developing an understanding of the regions of energy dissipation (chip formation, subsurface plastic working, tool edge radius ploughing) and the effects of the process parameters on the ultra-precision machining process. This will aid in possibly extending the range of tool/workpiece combinations currently considered suitable for ultra-precision machining. Specifically, the potential to apply single point diamond turning to the machining of II-VI compounds is being investigated. An experimentally verified, coupled mechanical/thermal energy model is being developed to provide an accurate predictive capability of the chip formation, tool wear processes, and resulting subsurface damage. Such a predictive capability will greatly aid in increasing the efficiency and accuracy of the ultra-precision machining process and the resulting workpiece quality.
Sponsors: Oklahoma Center for the Advancement of Science and Technology (Applied Research), Eagle-Picher Research Laboratories, and U.S. Department of Energy
PI: Don Lucca
RAs: Charles Babcock, William Edwards, and Craig Dickson
The Mechanics of Nanometric Cutting
Oklahoma State University, the University of North Carolina at Charlotte, and Los Alamos National Laboratory are collaborating on this project to build two highly-specialized instruments that will allow cutting with single-point diamond tools down to depths of cut approaching atomic dimensions (less than 1 nm). These instruments will be used in a series of experiments on ductile and brittle materials to provide a more fundamental understanding of nanometric cutting. This work will enable investigation of the physics of material removal at the nanometer scale and, in addition, could provide the basis for tribological studies at this scale.
Sponsor: National Science Foundation
PI: Don Lucca
RAs: Marla Bradley, Y. W. Seo, and Liu Lei
Nonlinear Control of Hydraulic Fracturing Pressures
Hydraulic Fracturing plays an important role in enhancing gas and petroleum production from otherwise marginal or uneconomical wells. Existing technology is well established, but the degree of automation is very small compared to other industrial fields. Application of extensive automation in this process has high potential to significantly increase well productivity from more effective hydraulic fracturing treatments. The project objective is the development of an Integrated Automatic Feedback Control System for Hydraulic Fracturing Treatments (implemented in software) that will incorporate the following features: control of bottomhole pressure and fracture geometry, based on geometry estimates provided by model-based state estimators; state-of-the-art nonlinear, model-based, robust automatic feedback controller; guaranteed stable control systems in the presence of modeling uncertainties; provide model-based estimates of relevant variables that may not be available from measurements; and provide model-based computer-aided decision tool for field operators.
Sponsors: Oklahoma Center for the Advancement of Science and Technology (Applied Research) and Halliburton Services, Incorporated
PIs: Eduardo A. Misawa and Gary E. Young
RAs: Jorge Chiriboga, Michael Moan, and Doug Harriman
Development of an In Situ System for Measuring Ground Thermal Properties
Ground source heat pump systems are an increasingly popular technology due to their energy efficiency, low operation and maintenance costs, and low environmental impact. For commercial buildings, their installation cost is highly dependent on the cost to drill the vertical boreholes that make up the ground loop heat exchanger. In turn, the design of the ground loop heat exchanger depends on a number of factors, of which limited knowledge of the ground thermal conductivity causes the most significant uncertainty. This project is focused on developing a system for measuring the overall effective thermal conductivity of the soil and rock surrounding the ground loop heat exchanger. When complete, it should significantly reduce the uncertainty in the ground loop heat exchanger design, thereby lowering the installation costs of such systems.
Sponsor: National Rural Electric Cooperative Association
PIs: Jeffrey D. Spitler
Marvin D. Smith (Engineering Technology)
Prevention of Bridge Deck Icing Using Geothermal Heat-Test Bridge Sections
Preferential icing is a condition where ice forms on a bridge while the adjacent roadways are clear. This condition is dangerous and leads to numerous accidents each year. A number of bridge deck heating systems have been developed for the purpose of eliminating preferential icing. Generally the systems have been economically unfeasible. This project involves the development of an alternative system, which uses ground source heat pumps, ground loop heat exchangers, and plastic pipe embedded in the bridge deck. A small scale test bridge is being constructed and instrumented. The goal is to demonstrate the concept and provide experimental data for validation of a computational model.
Sponsor: Oklahoma Department of Transportation
PIs: Jeffrey D. Spitler
Tim Hogue (Civil and Environmental Engineering)
RAs: Ojas Wadivkar and Chen-Jui Liao
Mathematics without Calculus
The Department of Mathematics provides education to a variety of students whose major does not require calculus. Many of these students have difficulty with the mathematical manipulations required in calculus-based courses and, predictably, lose interest in the subject. The goal of this project is to create a course to provide students with an appreciation of the intrinsic worth of mathematics, expose them to real applications of mathematics, and empower them with the skills necessary for analytical and mathematical reasoning. In short, the course should teach the process of mathematics without stressing skills required for the manipulation of mathematical variables. The course will not be a broad survey of either mathematics or its applications. It will, however, focus on a few significant and timely applications of mathematics provided by professionals from agriculture, biology, business, chemistry, engineering, music, physics, political science, and zoology. The course will utilize modern computer software tools to provide the necessary manipulations so that these students can better concentrate on the ideas and concepts of mathematics that can be directly employed in their individual disciplines.
Sponsor: National Science Foundation
PIs: Gary E. Young
Benny Evans, Bruce Crauder, and Alan Noell (College of Arts and Sciences)
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