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in subjects: "Combustion"

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Terascale High-Fidelity Simulations of Turbulent Combustion with Detailed Chemistry: Spray Simulations

The Terascale High-Fidelity Simulations of Turbulent Combustion (TSTC) project is a multi-university collaborative effort to develop a high-fidelity turbulent reacting flow simulation capability utilizing terascale, massively parallel computer technology. The main paradigm of the approach is direct numerical simulation (DNS) featuring the highest temporal and spatial accuracy, allowing quantitative observations of the fine-scale physics found in turbulent reacting flows as well as providing a u… more

Date: April 26, 2009

Creator: Rutland, Christopher J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Combustor oscillation pressure stabilizer

In accordance with the objective of the present invention, the active control of unsteady combustion induced oscillations in a combustion chamber fired by a suitable fuel and oxidizer mixture, such as a hydrocarbon fuel and air mixture, is provided by restructuring and moving the position of the main flame front and thereby increasing the transport time and displacing the pressure wave further away from the in-phase relationship with the periodic heat release. The restructuring and repositionin… more

Date: December 31, 1996

Creator: Gemmen, R. S.; Richards, G. A.; Yip, M. T. J.; Robey, E.; Cully, S. R. & Addis, R. E.

Item Type: Patent

Partner: UNT Libraries Government Documents Department

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Combustion instability in an acid-heptane rocket with a pressurized-gas propellant pumping system

Report presenting results of experimental measurements of low-frequency combustion instability of a 300-pound-thrust acid-heptane rocket engine as compared with the trends predicted by an analysis of combustion instability in a rocket engine. Results regarding the chugging frequency, combustion time delay, effect of rocket combustion-chamber characteristic length, effect of throttling, effect of injection velocity, effect of oxidant-fuel ratio, variation of chugging frequency with amplitude of … more

Date: May 1953

Creator: Tischler, Adelbert O. & Bellman, Donald R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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A Study of Combustion in a Flowing Gas

Note presenting the results of a preliminary study of combustion in flowing gases and apparatus for obtaining high rates of heat release per unit volume of combustion space are described. Tests were made over a wide range of fuel-air ratios, inlet-mixture velocities, and electrical heat inputs, using propane gas as the fuel. Results indicate that the greater the surface-volume ratio, or the greater the amount of heat addible to the gas stream, the greater the inlet-mixture velocity at which app… more

Date: April 1946

Creator: Gilbert, Mitchell; Haddock, Gordon & Metzler, Allen

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Some screeching-combustion characteristics of a transpiration-cooled afterburner having a porous wall of wire cloth

Report presenting an investigation of the screeching characteristics of two flame-holder configurations in a full-scale transpiration-cooled afterburner. The investigation indicated that a porous wall of wire cloth may be effective in eliminating or reducing the tendency to screech in some high-performance afterburners, but further testing is required. Results regarding the diametrical V-gutter, single-ring V-gutter, and durability of wire cloth are provided.

Date: November 29, 1954

Creator: Koffel, William K.; Harp, James L., Jr. & Bryant, Lively

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Steady Nuclear Combustion in Rockets

"The astrophysical theory of stationary nuclear reactions in stars is applied to the conditions that would be met in the practical engineering cases that would differ from the former, particularly with respect to the much lower combustion pressures, dimensions of the reacting volume, and burnup times. This application yields maximum rates of hear production per unit volume of reacting gas occurring at about 10(exp 8) K in the cases of reactions between the hydrogen isotopes, but yields higher r… more

Date: April 1957

Creator: Sänger, E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Effects of air-fuel spray and flame formation in a compression-ignition engine

"High-speed motion pictures were taken at the rate of 2,500 frames per second of the fuel spray and flame formation in the combustion chamber of the NACA combustion apparatus. The compression ratio was 13.2 and the speed 1,500 revolutions per minute. An optical indicator was used to record the time-pressure relationship in the combustion chamber. The air-fuel ratio was varied from 10.4 to 365. The results showed that as the air-fuel ratio was increased definite stratification of the charge occu… more

Date: August 26, 1935

Creator: Rothrock, A. M. & Waldron, C. D.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Experimental Study of Ignition by Hot Spot in Internal Combustion Engines

"In order to carry out the contemplated study, it was first necessary to provide hot spots in the combustion chamber, which could be measured and whose temperature could be changed. It seemed difficult to realize both conditions working solely on the temperature of the cooling water in a way so as to produce hot spots on the cylinder wall capable of provoking autoignition. Moreover, in the majority of practical cases, autoignition is produced by the spark plug, one of the least cooled parts in … more

Date: August 1938

Creator: Serruys, Max

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Some Factors Affecting Combustion in an Internal-Combustion Engine

"An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) … more

Date: September 11, 1934

Creator: Rothrock, A. M. & Cohn, Mildred

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Lagrangian Simulation of Combustion

A Lagrangian approach for the simulation of reactive flows has been developed during the course of this project, and has been applied to a number of significant and challenging problems including the transverse jet simulations. An efficient strategy for parallel domain decomposition has also been developed to enable the implementation of the approach on massively parallel architecture. Since 2005, we focused our efforts on the development of a semi-Lagrangian treatment of diffusion, and fast an… more

Date: May 1, 2008

Creator: Ghoniem, Ahmed F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Displacement speeds in turbulent premixed flame simulations

The theory of turbulent premixed flames is based on acharacterization of the flame as a discontinuous surface propagatingthrough the fluid. The displacement speed, defined as the local speed ofthe flame front normal to itself, relative to the unburned fluid,provides one characterization of the burning velocity. In this paper, weintroduce a geometric approach to computing displacement speed anddiscuss the efficacy of the displacement speed for characterizing aturbulent flame.

Date: July 1, 2007

Creator: Day, Marcus S.; Shepherd, Ian G.; Bell, J.; Grcar, Joseph F. & Lijewski, Michael J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Effect of Inlet-Air Parameters on Combustion Limit and Flame Length in 8-Inch-Diameter Ram-Jet Combustion Chamber

Report presenting an investigation with a ram-jet combustion chamber to determine the effect of fuel-air ratio and the inlet-air parameters of pressure, temperature, and velocity on combustion limit, combustion efficiency, and flame length.

Date: July 22, 1948

Creator: Cervenka, A. J. & Miller, R. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Combustion Velocity of Benzine-Benzol-Air Mixtures in High-Speed Internal-Combustion Engines

"The present paper describes a device whereby rapid flame movement within an internal-combustion engine cylinder may be recorded and determined. By the aid of a simple cylindrical contact and an oscillograph the rate of combustion within the cylinder of an airplane engine during its normal operation may be measured for gas intake velocities of from 30 to 35 m/s and for velocities within the cylinder of from 20 to 25 m/s. With it the influence of mixture ratios, of turbulence, of compression rat… more

Date: April 1932

Creator: Schnauffer, Kurt

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Self-Ignition and Combustion of Gases

This paper attempts to state laws for the self-ignition and combustion of gases in a comprehensive manner. The primary focus is recent investigations in which new combustion phenomena or new methods of studying them experimentally are brought out and investigations that throw new light on already known phenomena.

Date: August 1942

Creator: Sokolik, A. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Dust Combustion Safety Issues for Fusion Applications

This report summarizes the results of a safety research task to identify the safety issues and phenomenology of metallic dust fires and explosions that are postulated for fusion experiments. There are a variety of metal dusts that are created by plasma erosion and disruptions within the plasma chamber, as well as normal industrial dusts generated in the more conventional equipment in the balance of plant. For fusion, in-vessel dusts are generally mixtures of several elements; that is, the const… more

Date: May 1, 2003

Creator: Cadwallader, L. C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Pulse combustor with controllable oscillations

A pulse combustor having thermally induced pulse combustion in a continuously flowing system is described. The pulse combustor is fitted with at lease one elongated ceramic body which significantly increases the heat transfer area in the combustion chamber of the combustor. The ceramic body or bodies possess sufficient mass and heat capacity to ignite the fuel-air charge once the ceramic body or bodies are heated by conventional spark plug initiated combustion so as to provide repetitive igniti… more

Date: December 31, 1991

Creator: Richards, G. A.; Morris, G. J. & Welter, M. J.

Item Type: Patent

Partner: UNT Libraries Government Documents Department

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Combustion of n-heptane in a shock tube and in a stirred reactor: A detailed kinetic modeling study

A detailed chemical kinetic reaction mechanism is used to study the oxidation of n-heptane under several classes of conditions. Experimental results from ignition behind reflected shock waves and in a rapid compression machine were used to develop and validate the reaction mechanism at relatively high temperatures, while data from a continuously stirred tank reactor (cstr) were used to refine the low temperature portions of the reaction mechanism. In addition to the detailed kinetic modeling, a… more

Date: April 13, 1995

Creator: Gaffuri, P.; Curran, H.J.; Pitz, W.J. & Westbrook, C.K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Addition of Heat to a Compressible Fluid in Motion

From Introduction: "The purpose of this report is to summarize, without extended proofs, the results of a study of a simplified model of nonadiabiatic, compressible fluid flow, both subsonic and supersonic, and to state these results in a form that will make them immediately useful in providing a theoretical background for current technical problems of high-speed combustion.

Date: February 1945

Creator: Hicks, Bruce L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Simulation of lean premixed turbulent combustion

There is considerable technological interest in developingnew fuel-flexible combustion systems that can burn fuels such ashydrogenor syngas. Lean premixed systems have the potential to burn thesetypes of fuels with high efficiency and low NOx emissions due to reducedburnt gas temperatures. Although traditional scientific approaches basedon theory and laboratory experiment have played essential roles indeveloping our current understanding of premixed combustion, they areunable to meet the challe… more

Date: June 25, 2006

Creator: Bell, John B.; Day, Marcus S.; Almgren, Ann S.; Lijewski, MichaelJ.; Rendleman, Charles A.; Cheng, Robert K. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Pulsed Atmospheric Fluidized Bed Combustion. Technical Progress Report, July 1993--September 1993

This quarterly report is broken down between design and the status of the fabrication work being performed. The design section is divided between the following sections: Site layout, foundation design, structural design, piping design, pulse combustor components, and electrical & instrumentation design. As reported in the last quarterly report the location area of the PAFBC in the Clemson Energy Facility was inspected with a view to finalize the layout of the PAFBC plant. Some adjustments were … more

Date: October 30, 1993

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Pulsed atmospheric fluidized bed combustion. Quarterly technical progress report, October 1992--December 1992

The Design and Engineering of most components in the Pulsed Atmospheric Fluidized Bed System was completed prior to September 1992. The components remaining to be designed at that time were: Aerovalves for the Pulse Combustor; Gas and coal injectors for the Pulse Combustor; Lines for PC tailpipes; Air plenum and inlet silencer; Refractory lined hot gas duct connecting outlet hot cyclone to boiler; Structure and platforms, and ladders around PAFBC vessel access and major equipment. Design work i… more

Date: January 1, 1993

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Pulsed atmospheric fluidized bed combustion. Technical progress report, January--March 1994

Industra has completed design of the structure which surrounds the fluidized bed. Details regarding their efforts are discussed below. Duke/Fluor Daniel has begun overall design review and will provide comments and recommendations early in the second quarter. Foundation and control room design are complete. Drawings have been submitted to Clemson University and bids have been requested from vendors. Structural design is complete and drawings have been submitted for bids. Industra has reviewed d… more

Date: April 29, 1994

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Computational economy improvements in PRISM

The PRISM piecewise solution mapping procedure, in which the solution of the chemical kinetic ODE system is parameterized with quadratic polynomials, is applied to CFD simulations of H{sub 2}+air combustion. Initial cost of polynomial construction is expensive, but it is recouped as the polynomial is reused. We present two methods that help us to parameterize only in places that will ultimately have high reuse. We also implement non-orthogonal Gosset factorial designs, that reduce polynomial co… more

Date: January 29, 2003

Creator: Tonse, Shaheen R. & Brown, Nancy J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Final Report

The research funded by this grant yielded 20 papers with the P.I as the main author or a co-author. In this report, a brief outline of the completed projects is given.

Date: September 1, 2004

Creator: Cioslowski,J.

Item Type: Report

Partner: UNT Libraries Government Documents Department