| Microwave-Plasma-Coupled Re-Ignition of Methane-and-Oxygen Mixture Under Auto-Ignition Temperature |
Dec 2011 |
8 pages |
| Authors:
Xing Rao; Stephen Hammack; Campbell Carter; Timothy Grotjohn; Jr Asmussen Jes; Tonghun Lee; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
 | The re-ignition phenomenon is observed when fuel/oxidizer is re-introduced into an atmospheric-pressure plasma discharge generated by cutting off the gas flow in a re-entrant microwave-plasma applicator system used for plasma-assisted ignition and combustion research works. Results indicate that, for re-ignition to occur, the electric field must be strong enough to fully establish a weakly ionized and self-sustained plasma discharge and with elevated radical concentrations. The re-ignition was possible at gas ... |
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| Direct-Coupled Plasma-Assisted Combustion Using a Microwave Waveguide Torch |
Dec 2011 |
8 pages |
| Authors:
Stephen Hammack; Xing Rao; Tonghun Lee; Campbell Carter; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| A tunable microwave waveguide is used to initiate and enhance combustion by coupling an atmospheric plasma discharge to a premixed methane/air flame. The absorbed microwave power ranges from 60 to 150 W, which was generated from a continuous source operating at 2.45 GHz, whereas combustion power ranges from 200 to 1000 W. OH radical number densities were measured using planar laser-induced fluorescence (PLIF) and temperatures were measured using Rayleigh scattering ... |
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| Laser Diagnostics Study of Plasma Assisted Combustion for Scramjet Applications |
Dec 2011 |
31 pages |
| Authors:
Tonghun Lee; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| The main goal of this study is to apply advanced laser imaging and optical diagnostics to study the physicochemical impact of nonequilibrium plasmas to enhance the conversion of chemical energy in combustion, and to investigate new efficient concepts for coupling plasma energy into a flame, seeking future potential application in high speed engines including scramjets. Three separate topics have been investigated within the scope of this objective. The first topic ... |
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| Laser Diagnostic Imaging of Energetically Enhanced Flames Using Direct Microwave Plasma Coupling |
Nov 2011 |
3 pages |
| Authors:
Xing Rao; Stephen Hammack; Campbell Carter; Tonghun Lee; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Quantitative images of temperature and hydroxyl (OH) concentrations are presented in plasma-enhanced flames where a nonthermal microwave plasma discharge is coupled directly with the reaction zone of the flame. The plasma jet is generated through a novel microwave (2.45 GHz) waveguide based a coaxial reactor system. Planar laser-induced fluorescence is used to generate the OH fields, and planar Rayleigh scattering thermometry is used for the temperature. Plasma-enhanced flames present new ... |
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| Combustion Dynamics for Energetically Enhanced Flames Using Direct Microwave Energy Coupling |
Jan 2011 |
9 pages |
| Authors:
Xing Rao; Kadek Hemawan; Indrek Wichman; Campbell Carter; Timothy Grotjohn; Jes Asmussen; Tonghun Lee; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| An atmospheric high-Q re-entrant cavity applicator is used to couple microwave (2.45 GHz) electromagnetic energy directly into the reaction zone of a premixed laminar methane-oxygen flame for flame enhancement. As microwave energy increases, a transition from electric field enhancement to microwave plasma discharge is observed. At low microwave powers (1-5 W), the flame is influenced by an electromagnetic field only. When power is increased, ionization and eventually breakdown of gas ... |
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| Combustion Dynamics of Plasma-Enhanced Premixed and Nonpremixed Flames |
Dec 2010 |
8 pages |
| Authors:
Xing Rao; Steve Hammack; Tonghun Lee; Campbell Carter; Igor B Matveev; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Combustion dynamics are investigated for plasma-enhanced methane-air flames in premixed and nonpremixed configurations using a transient arc dc plasmatron. Planar laser-induced fluorescence images of hydroxyl (OH) and carbon monoxide (CO) radicals are obtained over a range of equivalence ratios (phi = 0.7-1.3), flow rates (6-18 LPM), and plasma powers (100-900 mA) to monitor radical propagation and in situ fuel reforming. The flow rates presented here are outside the range of ... |
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| Experimental Equipment for Powder Processing |
20 AUG 2009 |
25 pages |
| Authors:
Patrick Kwon; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| To increasing the safety factor of the space vehicles, Perspirable Skin, a new designed Thermal Protection System (TPS) was proposed by bio-mimicking the process of human sweating. Powder Metallurgy (P/M) was considered to be the best candidate method to fabricate core materials for Perspirable Skin. To perform the compaction and sintering as well as monitor the sintering kinetics/densification in the sintering, a Material Test System, MTS Insight 300 (MTS Systems ... |
|
| A Shock-Tube-Based Facility for Impact Testing |
01-Jan-2007 |
13 pages |
| Authors:
Qi Li; Dahsin Liu; Douglas Templeton; Basavarju Raju; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Many dynamic testing techniques use gas guns as a pressure generator. The pressure generated from the gas guns is often of low velocity and low energy and has a relatively random or short duration of a uniform pressure level. This kind of pressure is not well defined and cannot be converted into other application conditions. With aims at improving experimental capability and expanding the research horizon, a shock tube was ... |
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| Near Wall Velocity and Vorticity Measurements, In A Very High R(theta) Turbulent Boundary Layer |
15 JUN 2006 |
87 pages |
| Authors:
Scott C. Treat; John F. Foss; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Velocity and vorticity measurements have been obtained at two y+ values: 810 and 2,150, in the very high R(theta)(O 10(exp 6)) turbulent boundary layer at the SLTEST site, Dugway Proving Grounds, Utah. Detailed descriptions of the experimental procedures are reported in order to allow the processed results to be evaluated. The research focus is on the velocity-vorticity products that appear in the formal statement of the vertical gradient of the ... |
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| Development of an Efficient Micro-Heat Exchanger: The Integration of Design Processing and Testing |
NOV 2005 |
24 pages |
| Authors:
Patrick Kwon; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Many new concepts in designing and fabricating thermal management materials (TMMs) were explored to make an efficient meso-scale heat exchanger. The proposed TMMs have multi-functionality that combines structural material with cooling components by utilizing embedded microstructures in a miniature-sized body to enhance heat and mass transfer, chemical reactions etc. `Mesomachines' are expected to provide a number of important functions where a premium is placed on mobility, compactness, or point application. ... |
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| Parallel Simulation of Moving Boundary Flow Using Overset Adaptive Cartesian/Prism Grids and DES |
30 SEP 2004 |
15 pages |
| Authors:
Z. J. Wang; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Two major tasks have been undertaken in this year: the development of OverCart- the overset Cartesian/prism grid generator and adaptor, and the enhancement of the flow solver to handle moving overset Cartesian/prism grids. Satisfactory progresses have been made in both tasks, and we are on target and within budget to accomplish all the planned research and development efforts. More specifically, the following activities have been carried out from March 1 ... |
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| Improved Control Authority in Flexible Structures Using Stiffness Variation |
25 AUG 2004 |
10 pages |
| Authors:
Ranjan Mukherjee; Steven W. Shaw; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| This is the final progress report for AFOSR Contract #F49620-03-1- 0184, funded during the period Apr-December 2003. It summarizes the work done towards development of a new approach to vibration control of flexible structures. The main goal of this research is to improve control authority in structural systems through methodical stiffness variation, specifically, using end forces, such as follower forces. |
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| A Doppler Sensor Array for High-Resolution Measurements of the Wavenumber-Frequency Spectrum of the Turbulent Wall Pressure at High Reynold Numbers |
06 OCT 2003 |
46 pages |
| Authors:
Ahmed M. Naguib; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| The Doppler frequency shift is utilized as the basic sensing mechanism for a new unsteady-surface pressure measurement technique. The frequency shift is experienced by a focused laser beam reflected off the aluminized top of a flexible-polymer diaphragm subjected to the unsteady pressure. Prototypical sensors based on this concept, with different sizes and diaphragm material and thickness are constructed as well as evaluated. The results provide understanding of the limits of ... |
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| Simulation of Moving Boundary Flow Using Overset Adaptive Cartesian/ Prism Grids and DES |
SEP 2003 |
22 pages |
| Authors:
Z. J. Wang; Laiping Zhang; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Development of improved weapon systems requires better understanding of the complex aerodynamics created by moving boundaries. Carriage and release of conventional weapons from aircraft and aerial refueling fall in this category. The flow problem involving moving boundaries are very challenging to compute because the resultant flow field is intrinsically unsteady. Modeling such flow problems is made even more difficult due to the complex geometries and the highly turbulent nature of ... |
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| Simultaneous Whole-Field Measurements of Velocity and Concentration Fields Using Combined MTV and LIF |
07 JAN 2000 |
27 pages |
| Authors:
Manoochehr Koochesfahani; Richard Cohn; Colin MacKinnon; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| A new technique is described for the simultaneous measurement of velocity and concentration fields. We describe here applications in liquid-phase flows, but the methodology can be extended to gas-phase flows with appropriate tracers. In this single-laser, two-tracer approach, molecular tagging velocimetry (MTV) based on a phosphorescent compound is combined with laser induced fluorescence (LIF) using fluorescein as tracer. Results show that one can design experiments with minimal cross-talk between the ... |
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| The Accuracy of Remapping Irregularly Spaced Velocity Data onto a Regular Grid and the Computation of Vorticity |
1998 |
4 pages |
| Authors:
R. K. Cohn; M. M. Koochesfabani; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| The velocity data obtained from Molecular Tagging Velocimetry (MTV) are typically located on an irregularly spaced measurement grid. In this method of velocimetry, the flowing medium is premixed with a molecular complex that can be turned into a long life-time tracer upon excitation by photons. The velocity vector is determined from the displacement of small regions "tagged" by a pulsed laser which are imaged at two successive times within the ... |
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| Vorticity Field Evolution in a Forced Wake |
1997 |
3 pages |
| Authors:
Richard Cohn; Manoochehr Koochesfahani; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| The purpose of this work is to quantify the vorticity evolution in the flow field of the forced wake of a splitter plate inside a confining geometry. The interest in this flow stems from the fact that forcing a low Reynolds number 2-D wake can lead to a highly three-dimensional flow and a large increase in mixing 1. Our recent estimates, based on chemically reacting LIF measurements, report the amount ... |
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| Molecular Mixing in Shear Layers Forced by 2-D and 3-D Disturbances |
30 APR 96 |
24 pages |
| Authors:
Manoochehr M. Koochesfshani; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| The mixing characteristics of forced two stream shear layers and wakes have been investigated using both chemically reacting and nonreacting LIF technique. The shear layer results reveal that major modifications of the mixing field occur at relatively high values of x* > 2, and not in the enhanced growth region x* < 1. The non-dimensional downstream distance is defined by x * = x(lambda)f/U sub c where x is the ... |
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| Molecular Mixing in Shear Layers Forced by 2-D and 3-D Disturbances |
26 OCT 94 |
153 pages |
| Authors:
Manoochehr M. Koochesfahani; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Experiments on 2-D forcing of shear layers were completed. Analysis of data from two different forcing techniques have revealed that much of the global aspects of the scalar mixing field appear to exhibit a universal behavior in terms of the non-dimensional downstream distance x * = x Xf/ Uc where X = (U1 -U2)/(U1 +U2) and Uc = (U1 +U2)/2. This universal behavior suggests that the total amount of mixing ... |
|
| Unsteady Flow Field of Large-Amplitude Pitching Airfoils |
01 FEB 94 |
33 pages |
| Authors:
Manoochehr M. Koochesfahani; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| This research program investigated the physical mechanisms involved in the onset of leading edge separation when airfoils pitch to high angles of attack. Both constant pitch rate and variable pitch rate motions were considered. The highlights of results from a combined experimental and computational effort are described in this report. The conclusions from this research indicate the need for boundary-layer resolved measurements of the flow behavior near the leading edge ... |
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| Estimation of Thermal Properties in Epoxy Matrix/Carbon Fiber Composite Materials. |
1992 |
|
| Authors:
Elaine P. Scott; James V. Beck; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
 | Accurate knowledge of the thermal characteristics of composites is important in any nonisothermal environment, and these characteristics are related to the thermal properties of the material. The focus of this study is on the estimation of the thermal properties, namely thermal conductivity and volumetric heat capacity, of AS4 surface treated carbon fiber (Hercules, Inc.)/BADGE-mPDA composites. The thermal properties perpendicular to the fiber axis were estimated using the Gauss minimization method ... |
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| Estimation of Thermal Properties of Composite Materials Without Instrumentation Inside the Samples. |
1992 |
|
| Authors:
B. Garnier; D. DELAUNAY; J. V. Beck; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Recent contributions of parameter estimation in the measurement of thermal properties are of great importance. In comparison with other techniques such as steady state (hot guarded plate, etc.) or transient (line source method, flash method, etc.), the use of parameter estima- tion provides more information and, in most cases, produces faster results. With technique the thermal conductivity and the volumetric specific heat are estimated simultaneously and as a function of ... |
|
| On the Application and Interpretation of Coherent Motion Detectors |
1991 |
300 pages |
| Authors:
Charles Paul Gendrich; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Coherent motions are understood to play an important role in enhancing the momentum transport of turbulent wall bounded shear flows, but determining whether or not a coherent motion is present in a given volume of space at a particular time is still a difficult task. Although most detection schemes were developed for use within a specific region above the wall, most are ultimately used throughout the entire boundary layer. Three ... |
|
| Sequential Estimation of Temperature-Dependent Thermal Properties. |
1991 |
|
| Authors:
James V. Beck; Arafa M. Osman; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Determination temperature dependencies of thermal properties in transient tests is described for a composite material. In some experiments, an individual test only partially covers the desired temperature range with subsequent tests covering additional ranges. If thermal properties are estimated from individual tests, there is a question of what temperature to assign the property values, since temperature varies during the test. If the thermal properties are assumed to vary with temperature ... |
|
| Manufacturing-Process-Driven Design Methodologies for Components Fabricated in Composite Materials |
MAR 90 |
|
| Authors:
M. V. Gandhi; B. S. Thompson; F. Fischer; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| The insatiable demand in the aerospace, military and industrial marketplaces for high-performance mechanical and structural systems has triggered the evolution of a new generation of products featuring advanced state-of-the-art components fabricated in composite materials. Whereas the methodologies for designing composite-based components have been relatively well developed, these methodologies do not explicitly incorporate the constraints and characteristics imposed by the specific manufacturing processes employed to fabricate these components. This deficiency is ... |
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| Manufacturing-Process-Driven Design Methodologies for Components Fabricated in Composite Materials |
90 |
|
| Authors:
M. V. Gandhi; B. S. Thompson; F. Fischer; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| The insatiable demand in the aerospace, military and industrial marketplaces for high-performance mechanical and structural systems has triggered the evolution of a new generation of products featuring advanced state-of-the-art components fabricated in composite materials. Whereas the methodologies for designing composite-based components have been relatively well developed, these methodologies do not explicitly incorporate the constraints and characteristics imposed by the specific manufacturing processes employed to fabricate these components. This deficiency is ... |
|
| The Characterization of Elastic Moduli and Damping Capacities of Graphite/Epoxy Composite Laminated Beams in Hygrothermal Environments, |
AUG 1989 |
|
| Authors:
C. Y. Lee; M. Pfeifer; B. S. Thompson; M. V. Gandhi; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| The hygrothermoelastodynamic response of polymeric composite materials is partially addressed by presenting a review of theoretical and experimental investigations on the dynamic elastic moduli and damping capacities of composite laminated beams fabricated from Hercules AS4/3501-6 prepreg and exposed to different hygrothermal conditions. The favorable correlation between the theoretical predictions based on the generic model developed here and the experimental response-data is anticipated to provide a basis for establishing viable design ... |
|
| Numerical Study of Thermal Conductivity of Fiber-Matrix Composite Materials |
89 |
|
| Authors:
Wei Cha; James V. Beck; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| The conductive heat transfer characteristics of a fiber-matrix composite material is studied in this paper. the effects on the effective thermal conductivity as a composite material due to 1)fiber thermal conductivity, 2)matrix thermal conductivity, 3)contact conductance at the fiber- matrix interface, and 4)fiber density are investigated. a method is suggested for using this information to estimate the thermal conductivities of fiber and matrix from the measured effective thermal conductivities of ... |
|
| Experimental Study of the Turbulence Production Mechanism in Boundary Layer Flows |
MAY 82 |
9 pages |
| Authors:
R. E. Falco; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| Progress has been made in experimental techniques, in data acquisition and film quality, in data reduction, in our data base of simultaneous visual and point measurements, and in our knowledge of the physics of turbulence production. We have learned how to make our laser sheets thinner than previously attained by using both mirrors and lenses. We have learned how to obtain 'almost' continuous data records up to 96 k bytes. ... |
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| An Experimental Study of Turbulence Production Mechanisms in Boundary Layer Flows |
27 MAR 1981 |
|
| Authors:
Robert E. Falco; MICHIGAN STATE UNIV EAST LANSING DEPT OF MECHANICAL ENGINEERING
|
| The mechanism of turbulence production is identified. Simultaneous flow visualization and hot-wire anemometry have been used. A new scaling of the burst rate has been found. (Author) |
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