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Articles 1 - 4 of 4
Full-Text Articles in Heat Transfer, Combustion
Numerical Investigation Of Shock-Induced Combustion Past Blunt Projectiles, Jagjit K. Ahuja
Numerical Investigation Of Shock-Induced Combustion Past Blunt Projectiles, Jagjit K. Ahuja
Mechanical & Aerospace Engineering Theses & Dissertations
A numerical study is conducted to simulate shock-induced combustion in premixed hydrogen-air mixtures at various free-stream conditions and parameters. Two-dimensional axisymmetric, reacting viscous flow over blunt projectiles is computed to study shock-induced combustion at Mach 5.11 and Mach 6.46 in hydrogen-air mixture. A seven-species, seven reactions finite rate hydrogen-air chemical reaction mechanism is used combined with a finite-difference, shock-fitting method to solve the complete set of Navier-Stokes and species conservation equations. In this approach, the bow shock represents a boundary of the computational domain and is treated as a discontinuity across which Rankine-Hugoniot conditions are applied. All interior details of …
Effects Of Blowing Ratios On Heat Transfer To The Throat Region Of A Porous-Walled Nozzle, Fu-Jung Chen
Effects Of Blowing Ratios On Heat Transfer To The Throat Region Of A Porous-Walled Nozzle, Fu-Jung Chen
Theses and Dissertations
The effects of transpiration cooling on heat transfer in the throat region of a porous-walled nozzle were investigated. The experiments were performed in the AFIT low speed shock tube fitted with a Mach 2 nozzle. A blowing region was limited to the area from 1.3 cm prior to the throat to 1.2 cm downstream of the throat. The blowing ratios from -0.0002 (suction) to 0.0117 (blowing) of the main stream flow were studied. Heat flux data were taken from both sides of the nozzle. One side was transpiration cooled by secondary air injection through a porous wall, while the other …
A New Spray Evaporation Model Based On Droplet Interface Phenomena, Nihad E. Daidzic, Gangolf Kohnen, Martin Sommerfeld
A New Spray Evaporation Model Based On Droplet Interface Phenomena, Nihad E. Daidzic, Gangolf Kohnen, Martin Sommerfeld
Aviation Department Publications
In this work the influence of droplet shape oscillations on droplet evaporation is shown. Through nonlinear mode interactions, turbulence and aerodynamic triggering of vibrations cause by vortex shedding, droplets always oscillates in spray flows. Droplet shape oscillation cause higher evaporation rates through several physical phenomena such as an average increase of the superficial surface area, periodic micro-convection and boundary layer destruction, and local saturation pressure changes due to local curvature effects. The inviscid theory of small-amplitude droplet oscillations was used which resulted in better agreement with the measurement data of droplet size distributions in sprays for different axial coordinates.
Excess Heat Capacity Surfaces For Water-Alkanol Mixtures By The Uniquac Model, Yaşar Demirel, Halime Ö. Paksoy
Excess Heat Capacity Surfaces For Water-Alkanol Mixtures By The Uniquac Model, Yaşar Demirel, Halime Ö. Paksoy
Papers in Physical Chemistry
Hydroorganic mixtures are industrial solvents that can serve as media to solubilize either water in hydrocarbon or a hydrophobic substance in water. In many cases the solubilizing capability is obtained via a homogeneous complex aqueous mixtures containing an alcohol. Since excess heat capacity CPE, is very sensitive to structural changes in mixtures, concentration and temperature dependence of CPE have been calculated by using the UNIQUAC model for the mixtures methanol(l)-water(%, ethanol(l)-water(2), and l-propanol(l)-water(2). The temperature-dependent parameters of the model estimated directly from CPE data at more than one different isotherm are used in …