| Drop/Gas Interactions of Dense Sprays |
15 NOV 2001 |
155 pages |
| Authors:
G. M. Faeth; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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 | Turbulence generation and secondary drop breakup were studied. Turbulence generation is due to the motion of high-speed dispersed phases through continuous phases. Secondary drop breakup intrinsically follows primary liquid breakup in sprays. Measurements showed that flows caused by turbulence generation consisted of dispersed phase wakes (involving laminar-like turbulent wakes) surrounded by a turbulent interwake region involving isotropic turbulence in the final decay region. These measurements provided information about the properties ... |
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| Secondary Breakup and Turbulence Interactions of Drops |
JUL 1998 |
215 pages |
| Authors:
J. H. Chen; W. H. Chou; Z. Dai; J. S. Wu; G. M. Faeth; MICHIGAN UNIV ANN ARBOR
|
| Experimental studies of two types of drop/gas interactions that are important in the near injector, dense region of sprays were carried out, as follows: (1) secondary drop breakup, which tends to control transport processes in dense sprays; and (2) turbulence generation by rapidly moving drops in gas environments, which tends to control interphase turbulence production in dense sprays. The drop breakup measurements showed that breakup ... |
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| Breakup and Turbulence Generation in Dense Sprays |
30 SEP 95 |
109 pages |
| Authors:
L. P. Hsiang; J. S. Wu; W. H. Chou; J. H. Chen; G. M. Faeth; MICHIGAN UNIV ANN ARBOR
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| Single and double pulse holography was used to measure the outcomes of secondary drop breakup after shock wave disturbances in air at normal temperature and pressure; the resulting drop breakup regimes and drop size and velocity distributions were successfully interpreted and correlated based on phenomenalogical analysis. Laser velocimetry was used to measure the properties of sphere wakes at moderate Reynolds numbers (less than 1000) in turbulent environments (relative turbulence intensities ... |
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| Drop/Gas Interactions in Dense Sprays |
30 SEP 92 |
117 pages |
| Authors:
L..-p. Hsiang; J.-s. Wu; M. Mizukami; G. M. Faeth; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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| This is a final report of research considering three types of drop/ gas interactions that are important. in the near-injector, dense region of sprays, namely: (1) secondary drop breakup, which is an intrinsic outcome of primary breakup and is the most significant rate process of dense sprays; (2) turbulence generation by dispersed phases, which is the most significant source of turbulence production within dense sprays; and (3) the structure of ... |
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| Drop/Gas Interactions in Dense Sprays |
15 AUG 91 |
7 pages |
| Authors:
G. M. Faeth; MICHIGAN UNIV ANN ARBOR
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| Two processes of dense sprays are being studied: (1) turbulence modulation, which involves the turbulent field generated by drop motion; and (2) secondary drop breakup which can be the rate controlling process in dense sprays. Since past work on turbulence modulation highlighted the need for information on drop wake properties for low drop Reynolds numbers (10-1000), measurements of these flows are in progress using spheres traversing in stagnant glycerol baths. ... |
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| High-Speed Multiphase Mixing Layers |
AUG 91 |
156 pages |
| Authors:
L. K. Tseng; P. K. Wu; G. M. Faeth; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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| This is the final report of a research program whose objective was to study the structure and liquid breakup properties of high-speed multiphase mixing layers. The research is relevant to both gas injection into liquids, e.g. , liquid metal combustion processes, and liquid injection into gases, e.g., pressure-atomized sprays. The investigation was divided into two phases, considering the structure of multiphase mixing layers and primary breakup at liquid surfaces, respectively. ... |
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| Turbulent Premixed Hydrogen/Air Flames |
15 FEB 91 |
108 pages |
| Authors:
S. Kwon; M. S. Wu; J. F. Driscoll; G. M. Faeth; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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| The properties of turbulent premixed flames were investigated both theoretically and experimentally. Attention was limited to hydrogen/air mixtures burning as either turbulent jet flames or a freely propagating flames in isotropic turbulence. The research has application to a variety to premixed turbulent combustion processes: underwater metal cutting at great depth, primary combustors for high-speed airbreathing propulsion systems, afterburners, fuel/ air explosions, and spark-ignition internal combustion engines. Major findings of this ... |
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| Drop/Gas Interactions in Dense Sprays |
15 AUG 90 |
6 pages |
| Authors:
G. M. Faeth; MICHIGAN UNIV ANN ARBOR
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| Two drop/gas interactions important in the near-injector dense region of sprays are being studied: (1) turbulence modulation, which is the direct generation or modification of turbulence by drop motion, and (2) secondary drop breakup, an important rate-controlling process in dense sprays. Effects of turbulence modulation were measured in homogeneous flows generated by particles falling in stagnant air and water baths. The flow was analyzed with a simple stochastic approach, involving ... |
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| Structure of Monopropellant Spray Flames at Elevated Pressures |
15 JAN 90 |
89 pages |
| Authors:
G. M. Faeth; T.-w. Lee; M. E. Kounalakis; L.-k. Tseng; MICHIGAN UNIV ANN ARBOR GAS DYNAMICS LABS
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| The combustion properties of HAN-based monopropellants (LGP1845 and 1846) were studied, considering: liquid surface properties and conditions required for the thermodynamic critical point to be reached, drop combustion properties in combustion gas environments at pressures of 0.2-7.0 MPa, and pressure-atomized spray combustion properties in combustion gas environments at pressures of 3-9 MPa. Computations of liquid surface properties in flame environments indicated unusually high liquid surface temperatures, ca. 1000K, and critical ... |
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| Holocinematography for Studies of Turbulent Multiphase Flow |
15 JAN 90 |
29 pages |
| Authors:
G. M. Faeth; G. A. Ruff; L. P. Bernal; MICHIGAN UNIV ANN ARBOR GAS DYNAMICS LABS
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| The development of a high-speed holocinematography system for three- dimensional time-dependent measurements of the dynamics of dispersed flows is described. An on-line system based on a copper-vapor laser was assembled and used to obtain holocinematogram film strips of a particle-containing flow field. The present system can operate at framing rates up to 6000 holograms per second, yielding film strips up to 70 holograms long with a field of view having ... |
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| Dense-Spray Properties: Structure and Turbulence Modulation |
AUG 89 |
119 pages |
| Authors:
G. A. Ruff; R. N. Parthasarathy; G. M. Faeth; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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| A theoretical and experimental study of aspects of dense sprays is described, considering: the structure and mixing properties of the near- injector, dense-spray region of pressure-atomized sprays; and the direct effect of particle (drop) motion on the turbulence properties of multiphase flows (which is often called turbulence modulation). The structure of dense sprays was studied using large-scale (9.5 and 19.1 mm jet exit diameters) water sprays in still air. Measurements ... |
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| Underexpanded Noncondensing Turbulent Gas Jets in Liquids |
AUG 88 |
79 pages |
| Authors:
E. Loth; G. M. Faeth; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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| The structure of turbulent noncondensing round and plane air jets submerged in still water were investigated experimentally. Both adapted and underexpanded jets were considered, the latter with underexpansion ratios up to 8:1. Measurements included flow visualization, using flash photography and shadowgraphs as well as high-speed motion-picture photography; mean void fraction distributions, using gamma-ray absorption; entrainment rates, using laser-Doppler aneomometry; and mean static pressures, using static-pressure probes. Present measurements and the ... |
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| Turbulence Modulation and Dense-Spray Structure |
AUG 88 |
92 pages |
| Authors:
R. N. Parthasarathy; G. A. Ruff; G. M. Faeth; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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| A theoretical and experimental study of phenomena related to dense sprays is described. Two aspects of dense sprays are being considered: effects of turbulence modulation, which is the direct effect of particle (drop) motion on the turbulence properties of multiphase flows; and the structure and mixing properties of the dense-spray region of pressure atomized sprays. Turbulence modulation is being studied by considering spherical monodisperse glass particles falling in a stagnant ... |
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| Noncondensing Round Turbulent Gas Jets in Liquids |
OCT 87 |
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| Authors:
E. Loth; G. M. Faeth; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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 | The structure and mixing properties of noncondensing round turbulent air jets in still water was investigated experimentally, considering both subsonic and sonic underexpanded (with underexpanded ratios up to 8:1) jet exit conditions. Measurements included flow visualization, using flash and high-speed motion-picture photography; mean void fraction distributions, using deconvoluted gamma-ray absorption measurements; mean entrainment velocities, using laser- Doppler anemometry; and mean static pressures along the axis, using a static pressure probe. ... |
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| The Structure of Sonic Underexpanded Turbulent Air Jets in Still Air |
SEP 87 |
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| Authors:
S. G. Chuech; M. C. Lai; G. M. Faeth; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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| Turbulent subsonic, sonic and underexpanded round air jets, in still air, were studied both theoretically and experimentally. The following measurements were made: shock-wave structure of the underexpanded jets, using flash and continuous Schlieren photography; mean and fluctuating concentrations and mean static pressures, using laser-induced fluorescence; and mean and fluctuating streamwise velocities, using laser-Doppler anemometry. Analysis included: solution of the parabolized Navier-Stokes equations of motion; and use of effective adapted-jet exit ... |
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| Turbulence Interactions in Single- and Multi-Phase Turbulent Mixing and Combustion Processes |
15 AUG 87 |
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| Authors:
G. M. Faeth; R. N. Parthasarathy; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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| Turbulent multiphase flows (particle-laden jets, particle-laden flows in ducts, sprays, etc.) have technical applications for the combustion processes of airbreathing propulsion systems, and solid and liquid rocket motors. This report describes an upgrade of a single channel laser Doppler anemometer (LDA) to provide critical measurements needed to gain a better understanding of this class of multiphase flows. The upgrade yields a system which can be configured in several ways: a ... |
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| Dense-Spray Structure and Phenomena: Part 2 - Pressure-Atomized Sprays |
15 AUG 87 |
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| Authors:
G. A. Ruff; G. M. Faeth; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
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| A theoretical and experimental study of the dense-spray region of pressure-atomized nonevaporating sprays is described, emphasizing operation in the wind-induced and atomization breakup regimes. Experiments involved large- scale (9.5 an 19.1 mm injector diameters) water jets in still air. The flows were visualized using flash photography. In addition, the following measurements were made: mean and fluctuating streamwise velocities at the injector exit, mean liquid volume fraction distributions, and mean entertainment ... |
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| Dense-Spray Structure and Phenomena. Part 1. Turbulence/Dispersed-Phase Interactions |
15 AUG 87 |
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| Authors:
R. N. Parthasarathy; G. M. Faeth; MICHIGAN UNIV ANN ARBOR GAS DYNAMICS LABS
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| This report describes one aspect of an investigation of dense-spray processes: namely turbulence/dispersed-phase interactions. The work was divided into two phases: (1) measurements of particle-laden jets injected into a still liquid; and homogenous particle flows, consisting of particles falling in a still (in the mean) liquid bath. The structure of turbulent, dilute, particle- laden water jets, submerged in still water, was studied both experimentally and theoretically. Nonintrusive measurements were made ... |
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| Dense-Spray Structure and Phenomena |
15 AUG 86 |
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| Authors:
R. N. Parthasarathy; A. Sagar; G. M. Faeth; MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING
|
| This report describes theoretical and experimental study of dense sprays. The work was divided into two phases: (1) an investigation of particle laden water jets; and (2) an investigation of large scale liquid jet in the atomization regime. The particle laden jet experiments involved nearly monodisperse glass particles in water injected into still water, to simulate phase density ratios typical of high pressure sprays. Preliminary findings suggest that the locally ... |
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| Turbulent Noncondensing and Condensing Gas Jets in Liquids |
AUG 85 |
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| Authors:
T. Y. Sun; S. G. Chuech; R. N. Parthasarathy; G. M. Faeth; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL ENGINEERING
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| Gas injection into liquids is a fundamental multiphase flow which has several direct applications, e.g., stored chemical energy propulsion systems (SCEPS), direct-contact condensers, gas dissolution systems, reservoir destratification systems and nuclear-reactoar pressure suppression systems. Stability of these flow is enhanced when an underexpanded jet is used; therefore, the interaction of supersonic wave structures with liquids in turbulent flow is also an issue. The objective of this phase of the study ... |
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| Status of Boron Combustion Research |
OCT 84 |
145 pages |
| Authors:
G. M. Faeth; AIR FORCE OFFICE OF SCIENTIFIC RESEARCH BOLLING AFB DC
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| This report describes the proceedings of an AFOSR-sponsored Specialists Meeting on Boron Combustion. The objectives of the meeting were to review current understanding and to recommend fundamental research needs concerning boron combustion. Combustion of both slurries and solid propellants containing boron was considered for airbreathing propulsion applications. Boron can provide more than twice the volumetric energy density of conventional hydrocarbon fuels for airbreathing propulsion systems--substantially improving the performance of volume-limited ... |
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| Status of Boron Combustion Research, |
OCT 1984 |
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| Authors:
G. M. Faeth; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
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| This paper describes the proceedings of an AFOSR-sponsored Specialists Meeting on Boron Combustion held in June 1984. The objectives of the meeting were to review current understanding and to recommend fundamental research needs concerning boron combustion. Combustion of both slurries and solid propellants containing boron was considers for airbreathing propulsion applications. Boron can provide more than twice the volumetric energy density of conventional hydrocarbon fuels for airbreathing propulsion systems-substantially improving ... |
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| Gasification of Boron Oxide Drops and Boron Slurry Agglomerates in Combustion Gases, |
OCT 1984 |
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| Authors:
S. R. Turns; J. T. Holl; A. S. P. Solomon; G. M. Faeth; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
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| The behavior of boron oxide drops as well as agglomerates of boron particles, which are formed during the combustion of boron slurry fuels, was studied in the post flame region of a flat-flame burner. Individual particles having initial diameters of 150-800 microns were supported on a probe and could be rapidly placed in the gas environment. Measurements were made of the variation of particle electron microscope. Burner operating conditions were ... |
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| Combustion of Agglomerates Formed by Carbon Slurry Fuels |
NOV 1983 |
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| Authors:
S. R. Turns; S. P. Riddle; G. M. Faeth; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL ENGINEERING
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| A theoretical and experimental study of the reaction of carbon-black agglomerates, which are formed during the combustion of carbon-black slurry fuels, is reported. Theoretical work includes development of a one-dimensional model of a carbon slurry-fueled combustor in order to gain insight concerning effects of slurry properties and combustor operating conditions on combustor performance. New experiments were also undertaken in order to study effects of carbon-black composition and catalyst loading on ... |
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| Combustion of Agglomerates Formed by Carbon Slurry Fuels |
SEP 1982 |
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| Authors:
G. A. Szekely Jr.; G. M. Faeth; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL ENGINEERING
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| The reaction of carbon-black agglomerates, formed during the combustion of carbon slurry fuels, is considered. A monodisperse stream of agglomerates (10-75 micrometers initial diameter) was observed in the post-flame region of a flat-flame burner yielding particle size, mass, temperature and velocity as a function of time in the burner gases. Test considered burner fuel equivalence ratios of 0.2-1.4, and gas temperatures of 1620-1960 K at atmospheric pressure. Several carbon-black formulations ... |
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| An Investigation of Slurry Fuel Combustion. |
JAN 1981 |
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| Authors:
G. A. Szekely; G. M. Faeth; DAYTON UNIV OH SCHOOL OF ENGINEERING
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| A theoretical and experimental investigation of the combustion properties of carbon slurry fuels was performed. This involved observing the combustion of individual drops (400-1000 micrometer in diameter) supported at various positions within an open, turbulent diffusion flame. When a slurry drop was exposed to the flame, the liquid fuel in the slurry evaporatd in the first stage, leaving a carbon agglomerate consisting of all the carbon particles originally in the ... |
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| Investigation of Critical Burning of Fuel Droplets. |
JUL 1979 |
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| Authors:
G. M. Faeth; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL ENGINEERING
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| A description of the research conducted under this grant is given including theoretical and experimental methods, and major results. Three areas are discussed: (1) combustion of bipropellant droplets with particular emphasis on high presure conditions where the drop approaches or exceeds its thermodynamic critical point during combustion; (2) combustion of hydrazine fuels, treating hybrid drop combustion in combustion gas environments and the open-loop response of hydrazine strands, drops and sprays ... |
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| Evaluation of a Reactive-Heat-Pipe Employing an Arterial Wick |
JUN 1978 |
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| Authors:
G. A. Szekely; G. M. Faeth; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL ENGINEERING
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| This report describes a theoretical and experimental study of the use of arterial wicks in conjunction with a reactive-heat-pipe combustor for the lithium-sulfurhexafluoride reactant combination. The theory suggests substantial increases in allowable wick power densities (to levels on the order of MW/sq m) when arterial wicks are used, improving the compactness of the combustor system. Tests were conducted to determine maximum wick power densities. A 15 kW combustor was used, ... |
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| A Study of a Liquid Metal Thermal Energy Source |
JUN 1978 |
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| Authors:
G. M. Faeth; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL ENGINEERING
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| A study of combustor systems for the lithium-sulfurhexafluoride reaction combination is described. The objective of the study was to develop a combustor which could operate as a thermal energy source for long periods with variable thermal power levels. Several combustor concepts were examined, including: batch combustors with submerged injectors, steady combustors with submerged injectors, wall-mounted wick combustors and the reactive-heat-pipe. The reactive-heat-pipe was found to be the most attractive system ... |
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| SPONTANEOUS IGNITION DURING CHARGING PROCESSES IN PNEUMATIC AND HYDRAULIC SYSTEMS, |
OCT 1963 |
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| Authors:
G. M. Faeth; W. E. Meyer; PENNSYLVANIA STATE UNIV UNIVERSITY PARK
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| This report deals with the ignition of hydraulic fluids by means of compression processes caused by rapid pressurization of air filled portions of hydraulic and pneumatic systems. A theoretical analysis of the gas temperatures attained during the compression process is presented. Employing this analysis a reasonable correlation was obtained between the experimental conditions under which ignition would occur during a compression process and the spontaneous ignition temperatures of the hydraulic ... |
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