WorldCat Identities


Works: 131 works in 169 publications in 1 language and 173 library holdings
Classifications: QA911,
Publication Timeline
Solid propellant admittance measurements by the driven tube method by B.T Zinn( Book )

4 editions published between 1974 and 1977 in English and held by 4 WorldCat member libraries worldwide

The progress made during the fourth year of an investigation for the measurement of the response of a burning solid propellant to flow disturbances is presented. In this study a modification of the impedance tube technique is used to measure the response over a wide frequency range. Further refinements in the data reduction computer program are discussed. Anomalous behavior for high pressure (300 psig) tests which shows that the propellant sample periodically drives and damps acoustic oscillations during a burn was resolved. Techniques for improving the accuracy of the measured data and the quality of the burn have been developed. Testing will resume during the next year. (Author)
Two approaches to the three-dimensional jet-in-cross-wind problem : a vortex lattice model and a numerical solution of the Navier-Stokes equations by Joe Floyd Thompson( Book )

2 editions published in 1971 in English and held by 3 WorldCat member libraries worldwide

A three-dimensional numerical solution of the time-dependent, incompressible Navier-Stokes equations based on an integro-differential formulation of these equations is developed. With this formulation it is possible to obtain the complete solution in the entire flow field while restricting the actual computational field to the region of significant vorticity magnitude of each time. This allows a considerable reduction in the computer storage required, since only the field points having significant vorticity at any time need be stored at that time, and calculations are actually performed only at those points at that time. The validity of the numerical solution is established by comparison of the results with the exact solution for the time-dependent, one-dimensional flow over a suddenly accelerated infinite flat plate moving parallel to itself at constant velocity, and by comparison of surface pressure and drag coefficients with experimental results and with the results of other numerical solutions for the two-dimensional flow about a circular cylinder. The numerical solution is applied to the flow field of an infinite jet in a cross-flow and to the flow field of a jet issuing perpendicularly from an infinite plane wall into a cross-flow parallel to the wall. (Author)
Combustion generated noise in turbopropulsion systems( Book )

3 editions published between 1973 and 1975 in English and held by 3 WorldCat member libraries worldwide

The results are presented of a three year program investigating direct combustion noise in hydrocarbon-air flames. Tasks completed during the final year of the program have been (1) the use of an exterior facility to investigate the noise from a large, 2 inch diameter burner and (2) the use of the anechoic facility to test flames stabilized by bluff body flameholders. Emphasis in the program has been on premixed, fuel lean turbulent flames using ethylene, acetylene, propane and propylene fuels with air as the oxidizer. Conclusions of practical interest are (1) combustion noise can be an important contributor to the overall noise problem from turbopropulsion systems if the system extracts high shaft power, (2) it is not important to the nosie problem from afterburning turbopropulsion systems, (3) if the noise output of a particular combustor type is known in one installation, valid predictions may be made for the noise output of the same type of combustor in a different installation and (4) combustion noise may be a contributor to the afterburner instability problem. (Author)
Rocket Research at Georgia Tech( Book )

3 editions published between 1979 and 1981 in English and held by 3 WorldCat member libraries worldwide

Progress is reported on four distinct projects which are administered as a group. The individual projects are identified as tasks and reported on separately. A summary for each task follows: Task I. Work concerned improvement and application of the impedance tube method for measurement of the presure-coupled combustion response of solid propellants and measurement of the bulk damping in the product flow. Improvements included increaed sites and amplitude range of pressure measurements; increased capacity of the data acquisition system; and a modified, more rapid data reduction program. Admittances and bulk loss coefficients of nonaluminized and aluminized propellants were measured over a range of frequencies. Task II. Studies were continued on external burning using an axisymmetric model at Mach 3. Tests with actual combustion of radially and axially injected hydrogen are then reported. Outstanding performance values with significant base drag reduction is shown for injection and burning directly in the near-wake (base burning). Task III. Investigations continued of the accumulation processes of aluminum on the propellant burning surface that lead to formation of agglomerate droplets, the size of which dominates aluminum combustion. Task IV. Experimental and analytical studies were continued on the subject of turbulence-induced pressure fluctuations in a rocket-like cavity. A new theory was constructed for the generation of pressure disturbances by the turbulence. Undeniable separation has been achieved between propagational and local pressure fluctuations, and the agreement between theory and experiment are adequate
Audible and Ultrasonic Acoustic Emissions from Composite Solid Propellants( Book )

3 editions published between 1975 and 1977 in English and held by 3 WorldCat member libraries worldwide

The audible and ultrasonic acoustic emissions from deflagrating composite solid propellants were monitored and analyzed to evaluate their potential use as diagnostics of the combustion and as a means for the study of fundamental burning processes. A family of composite HTPB-AP propellants were tested which include a range of AP particle sizes, aluminized and nonaluminized formulations, the effect of the addition of a catalyst, and the presence of an AFCAM aluminum coating. For the audible emissions, the frequency behavior in the 0-10 kHz range can be explained by assuming the gas phase reaction time primarily controls the oscillating frequency. The combustion noise efficiency, cannot be explained by the theories put forth, so the physical makeup of the noise source is presently unknown. Analysis of the ultrasonic emission spectra indicates that there are no distinct spectral features which can be used to identify a particular propellant by its acoustic signature. The rms emission levels, however, can be used as a reliable, nonintrusive means for detecting flaws in the propellant, identifying bad burns, and measuring burn rates. The overall level increases with increasing burn rate and chamber pressure and decreasing particle size. (Author)
Investigation of the Flame-Acoustic Wave Interaction during Axial Solid Rocket Instabilities( Book )

3 editions published between 1985 and 1991 in English and held by 3 WorldCat member libraries worldwide

The primary objective of this study is the determination of the fundamental mechanisms responsible for the driving of axial instabilities by solid propellant flames. During the report period, the behavior of a premixed flame stabilized on the side wall of a duct in the presence of an axial acoustic field was investigated both theoretically and experimentally. The developed model solutions show that driving occurs due to the combustion process heat addition while outside the reaction zone the waves are damped by viscous processes. This damping increases as the thickness of the acoustic boundary layer increases. Experimental facilities for studying oscillating duct flow sin the presence and absence of flames were developed. Cold flow studies verified the presence of an excess velocity region within the acoustic boundary layer (i.e., the Richardson Effect) and the dependence of the boundary layer thickness upon the frequency and wall injection velocity. Reactive flow studies showed that the behavior of the flame depends upon its location relative to the standing acoustic wave. When the flame was positioned next to a velocity antinode, unexpected instabilities appeared on its surface eventually resulting in severe flame distortion. Also, the measured C-C and C-H radiation signals were periodic and they oscillated with the same frequency as the acoustic wave. Keywords: Flame-Acoustic interactions; and Flame driving
Noise Suppression in Jet Inlets by Ben T Zinn( Book )

3 editions published between 1978 and 1980 in English and held by 3 WorldCat member libraries worldwide

This report summarizes the work performed during the second year of an AFOSR sponsored research program that was primarily concerned with the development of an analytical technique for determining the radiated sound field from axisymmetric jet engine inlet configurations. The analytical technique employed is based upon an integral representation of the external (radiation) solutions of the Helmholtz equation which describe the sound fields external to a given body under either no flow or constant velocity flow situations. The integral representation developed during the course of this research program is different from earlier works in the sense that it not only yields the correct (unique) solution for all radiation problems at all frequencies, but that the resulting integral equations contain no strong (i.e., nonintegrable) singularities and therefore can be solved by straight forward numerical techniques
Potential Flow Studies of Lift-Fan Inflow Interference Phenomena( Book )

1 edition published in 1973 in English and held by 2 WorldCat member libraries worldwide

The report presents results of a study of the lift-fan inlet problem and includes a comprehensive survey of the existing experimental data and analytical methods, an analysis of the potential flow, and a boundary layer analysis for lift-fan inlets. Numerical solutions are presented for potential flows associated with inlet ducts set in an infinite plane with and without a centerbody simulating the hub of the fan. The effects of the cross flow to mean inlet velocity ratio, of the inlet and hub lip radii to duct width ratio, of the inclination of the duct axis to the plane, and of the position of the hub relative to the plane on the flow in and near the inlet ducts are discussed utilizing a two dimensional potential flow analysis. (Modified author abstract)
Studies in Non-Linear Unsteady Aerodynamics( Book )

2 editions published between 1986 and 1989 in English and held by 2 WorldCat member libraries worldwide

This report describes the research effort carried out under AFOSR Grant 86-0121. Two new unified theoretical-computational methods for analyzing unsteady aerodynamics involving rapid large amplitude motion of lifting bodies are described. One method is based on the zonal solution of the full Navier-Stokes equation and the other method is a simplified zonal method. Selected results are presented for two-dimensional rigid, articulate and flexible lifting bodies. Preliminary results for three-dimensional problems are also presented. Unsteady aerodynamics, Supermaneuverability. (EG)
A Method of Preliminary Design Analysis for Normal Impact of Earth Penetrators by L. W Rehfield( Book )

1 edition published in 1977 in English and held by 2 WorldCat member libraries worldwide

A simplified method of analysis for use in preliminary design of earth penetrators has been developed. The objectives have been simplicity, rapid turnaround and low cost, in addition to sufficient accuracy for adequate prediction of primary physical processes and associated variables. Based upon a stress wave transmission approach, the method applies to axisymmetric response of projectiles of revolution due to normal impact events in its current state of development. Results are presented for strain and acceleration time histories on a penetrator that has been impact tested. Analysis predictions and available experimental data are in excellent agreement, which indicates that the method is effective as well as efficient. (Author)
Integrated Reconfigurable Intelligent Systems (IRIS) for Complex Naval Systems( Book )

3 editions published between 2009 and 2011 in English and held by 2 WorldCat member libraries worldwide

The report details the research work has been done by the Aerospace Systems Design Laboratory (ASDL) in developing and applying the Integrated Reconfigurable Intelligent Systems (IRIS) concept for the period of February 22 to June 30, 2009. The main objective of the work for this period is to further develop and refine the integrated modeling and simulation environment in order to investigate the behavior of complex naval systems for improving the ship design and operations. Five individual tasks were conducted to fulfill this objective. Models revised based on the notional YP were integrated and tested; a control architecture with inference engine was proposed and evaluated based on defined scenarios; comparison of plain NN models and NN models with the block-structure was performed for evaluating accuracy of the surrogate models; a suitable framework and a database engine has been selected to facilitate the information management for developing the HMI of the simulation environment; a robust and a resilient approaches were proposed to conduct design space exploration in order to obtain an ultimate design with increased survivability and mission effectiveness. The rest of the report will explain the accomplishments for each task in details
Combustion Mechanisms of Solid Propellants by E. W Price( Book )

3 editions published between 1980 and 1993 in English and held by 2 WorldCat member libraries worldwide

A summary report is made of research on the latter phases of this contract, involving mechanisms of propellant combustion. In eight sections, work on the following is reported: (1) Status of understanding; (2) Decomposition of binders as revealed by hot stage microscope studies; (3) Systematic studies of combustion of 'sandwiches' of binder laminae between ammonium perchlorate laminae, with particular emphasis on quench-burning of thin-binder sandwiches; (4) Exploratory tests of combustion of other geometrically simple structures chosen to simulate other aspects of combustion of real propellants; (5) Systematic tests of a family of propellants to provide comparisons with results of tests on ordered structures; (6) development of a new analytical model for burning rate of propellants, based on the idea of determining the least-time-path for burning front to propagate through the microstructure from the burning surface to some relatively distant point in the propellant; (7) Development of a transient analysis of an axially symmetrical diffusion flame analogous to a burning oxidizer particle in a propellant matrix, and demonstration that the steady-state solution to this 'Burke-Schumann'-like problem is not dynamically stable (the complete analysis will be published separately); and (8) A restatement of the initial approach to the statistical model of propellant developed by Glick and Condon (presented to clarify the assumptions and method of the statistical approach). (Author)
Sublaminate Damage Mechanisms in Composite Structures by L. W Rehfield( Book )

2 editions published between 1986 and 1987 in English and held by 2 WorldCat member libraries worldwide

This interim report briefly summarizes the objectives, accomplishments and current direction of research on sublaminate damage mechanisms in composite structures. A Mode I suppression series of experiments and a companion analysis have been completed for graphite-epoxy double cracked-lap-shear specimens. The results show that a very small transverse normal force, 1-3% of the axial tensile force, is all that is needed to suppress Mode I action in interlaminar fracture. Complementary experiments on low cycle fatigue in tension and compression and on Mode I suppression in tension have been performed. The former confirm earlier static findings. The latter are also in agreement with static findings and illustrate the effectiveness of Mode I suppression technology. A practical working approach to analysis and design against delamination has been formulated. A simple fracture law is found to represent the existing data on four graphite-epoxy material systems and one glass-epoxy system created by a number of investigators on a variety of types of specimens. It has an intrinsic means of accounting for the observed high scatter of high Mode II (or Mode III), low Mode I delamination found in experiments. Keywords: Delamination, Interlaminar fracture, Damage in composites, Composite materials
Behavior of aluminum in solid propellant combustion by Edward Warren Price( Book )

2 editions published between 1976 and 1977 in English and held by 2 WorldCat member libraries worldwide

The behavior of various aluminum powders was observed during heating in controlled environments, using a hot stage microscope and a specially built hot plate drop apparatus (for rapid heating). Results show the effect of powder type, atmosphere, temperature, and binder type on formation of interconnected and coalesced particles, and help to clarify similar processes operative in the propellant combustion zone. Coalescence (agglomeration) tended to occur above the aluminum melting point, with the breakdown of the oxide shell on the particles (due to expansion of the melting aluminum) being a key factor. Conditions that inhibited contact of molten aluminum between particles inhibited coalescence, but usually caused particles to become interconnected. These conditions included oxidizing atmosphere or presence of propellant binder materials. (Author)
Combustion Instability in Solid Propellant Rockets( Book )

2 editions published between 1987 and 1989 in English and held by 1 WorldCat member library worldwide

This project concerns assembly, synthesis and comprehensive presentation of information on combustion instability in solid rockets, in the form of a reference book. The format is chosen to make the book suitable for a wide audience of readers including propulsion program managers, motor designers, propellant chemists, test engineers, and combustion specialists. The diversity of audience is accommodated by opening with general introductory chapters for nonspecialist, with progression into more applied issues, such as experimental methods and remedial measures. All chapters open with Introductions that give a relatively non-technical statement of the problem and content, and end with a qualitative summary of what was done in the chapter. An extensive bibliography is included, and supplemented by a more complete, computer-based bibliography with search-retrieval capability
Technologies for Future Precision Strike Missile Systems( )

3 editions published in 2000 in English and held by 0 WorldCat member libraries worldwide

This report documents the results of NATO Research and Technology Organization (RTO) lecture series number 221, entitled "Technologies for Future Precision Strike Missile Systems." The lecture series was conducted under the RTO Consultant and Exchange (C & E) Program as a two-day educational event, first held March 23-24, 2000 in Atlanta Georgia, at the Georgia Institute of Technology. Following the lectures at Georgia Tech, the lectures were held April 3-4 in Turin, Italy and April 6-7 in Ankara, Turkey. The primary purpose of the lecture series was the disseminating of state-of-the-art scientific and technical knowledge among a wide audience. The lecture series director and three other speakers provided lectures. Emerging technologies for precision strike missile systems that were addressed in the lecture series included
Combustion mechanisms of solids by Edward W Price( )

3 editions published between 1986 and 1992 in English and held by 0 WorldCat member libraries worldwide

This report summarizes the studies of ingredient decomposition and sandwich burning during the period October 1985 to September 1988. A CO2 laser pyrolysis facility was built and preliminary tests on propellant ingredients were conducted. Results showed presence of a liquid state or reacting froth on the surface of all ingredients tested (AP, AN, PBAN, NMMO and BAMO-THF). Ingredient combustion behavior was studied by the edge burning sandwich method using sandwiches of AP with PBAN, NMMO and BAMO-THF. The effects of Fe203, Fe204 and catocene (10% level in the binder lamina) were evaluated. Burning with BAMO- THF was qualitatively similar to that with PBAN, with the correspondingly high burning rate. Combustion, Solid propellant
LES of Sooting Flames( )

2 editions published in 2006 in English and held by 0 WorldCat member libraries worldwide

Soot prediction in realistic systems is one of the most challenging problems in theoretical and applied combustion. Soot formation as a chemical process is very complicated and not fully understood up to the moment. The major difficulty stems from the chemical complexity of the soot formation processes as well as its strong coupling with the other thermochemical and fluid processes that occur simultaneously. Soot is a major byproduct of incomplete combustion, having a strong impact on the environment, as well as the combustion efficiency. Therefore, it needs to be predicted in realistic configurations in an accurate and yet computationally efficient way. In the current study, a new soot formation subgrid model is developed and reported here. The new model is designed to be used within the context of the Large Eddy Simulation (LES) framework, combined with Linear Eddy Mixing (LEM) as a subgrid combustion model. The final model can be applied equally to premixed and non-premixed flames over any required geometry and flow conditions in the free, the transition, and the continuum regimes. The soot dynamics is predicted using a Method of Moments approach with Lagrangian Interpolative Closure (MOMIC) for the fractional moments. Since, no prior knowledge of the particles distribution is required, the model is generally applicable. The effect of radiation is introduced as an optically thin model. As a validation the model is first applied to a non-premixed non-sooting flame, then a set of canonically premixed flames. Finally, the model is validated against a non-premixed jet sooting flame. Good results are predicted with reasonable accuracy
Numerical Solution of Three-Dimensional Unsteady Viscous Flows( )

3 editions published between 1991 and 1992 in English and held by 0 WorldCat member libraries worldwide

The behavior of free shear layers within ramjet dump combustors is studied through the numerical solution of unsteady compressible Navier-Stokes equations. Three configurations are considered: (a) a short combustor with an open downstream boundary, (b) a long combustor with an open downstream boundary, and (c) a short combustor with a partially blocked downstream boundary. Vorticity contours of the computed flow fields in all the three cases reveal oscillations of the shear layer, roll up and shedding of organized vortices. A Fourier analysis of the computed flow fields indicates that the natural acoustic frequency of the system, and the natural shear layer instability frequency are the two dominant frequencies of the flow field. It is also observed that the boundary conditions play a crucial role in the behavior of the combustor flow field
Controlling mechanisms of pulsating incineration processes by Benjamin T Zinn( )

3 editions published between 1994 and 1996 in English and held by 0 WorldCat member libraries worldwide

The purpose of this research program is to study the fundamental processes that control the performance of acoustically excited incineration systems. The information learned will be used in the development of a compact, high-efficiency waste incinerator for shipboard use. Tests performed during the current reporting period of this program have demonstrated that mixing and heat transport processes, both crucial to the incineration process, may be enhanced by imposing acoustic pressure oscillations. Because the combustion efficiency and pollutant emission characteristics of incinerators are directly affected by the mixing of in-flowing air with fuel, acoustic control of turbulent jets is of interest to the development of compact incinerators. Studies of jets subjected to transverse mode oscillations have shown that, under the proper conditions, the jet will shed large, alternating, vortical structures that can cause the jet to bifurcate. This process results in a greater spatial mixing rate. Transverse mode acoustic forcing had the greatest effect in the range of St = 0.2 - 0.3. The effect of acoustic oscillations upon solid fuel pyrolysis was investigated by studying the effect of acoustic oscillations upon dry ice sublimation. This study showed that the presence of pulsations enhanced the sublimation process, which strongly suggests that they would also enhance the processes involved in incinerating solid wastes. Also, a model incinerator that can burn liquid and solid waste surrogates in the presence of transverse and multi- dimensional mode acoustic oscillations has been developed
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