Large eddy probability density function (LEPDF) simulations for turbulent reactive channel flows and hybrid rocket combustion investigations.

Persistent Link:
http://hdl.handle.net/10150/187273
Title:
Large eddy probability density function (LEPDF) simulations for turbulent reactive channel flows and hybrid rocket combustion investigations.
Author:
Yi, Jianwen.
Issue Date:
1995
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
A new numerical simulation methodology, Large Eddy Probability Density Function (LEPDF), and corresponding numerical code have been developed for turbulent reactive flow systems. In LEPDF, large scale of turbulent motion is resolved accurately. Small scale of motion is taken care of by a modified Smagorinsky subgrid scale model. Chemical reaction terms are resolved exactly without modeling. A numerical scheme to generate inflow boundary conditions has been proposed for spatial simulations of turbulent flows. Monte-Carlo scheme is used to resolve filtered PDF (Probability Density Function) evolution equation. The present turbulent simulation code has been successfully applied in the simulations of transpired and non-transpired fully developed turbulent channel flows. It more accurately predicts turbulent channel flows than the existing temporal simulation code with only 27% of the grid size of the temporal simulation code. It has been shown that "Ejection" and "Sweep" are two dominant events in the wall region of turbulent channel flows. They are responsible for about 120% of the total turbulent production. Their interactions have negative contributions to the turbulent production, thereby keeping the total 100%. Counter-rotating vortex is a major mechanism responsible for turbulent production in boundary layer. It has also shown that injection from channel side walls increases the boundary layer thickness and turbulence intensities, but decreases the wall friction and heat transfer. Suction has opposite effects. A state-of-the-art hybrid rocket research laboratory has been established. Labscale hybrid rockets with fuel port diameters ranging from 0.5 to 4.0 inches have been designed and constructed. Rocket testing facilities for routine measurements and advanced combustion diagnosis techniques, such as infrared image technique and gas chromatography, are well developed. A computerized data acquisition/control system has been designed and built. A new Cu⁺⁺ based catalyst is identified which can improve the burning rate of general HTPB based hybrid rocket fuel by 15%. Scale-up principles are developed through a series of experimental testing on different sizes of hybrid rockets. A polymer (rocket fuel) degradation model with consideration of catalytic effects of small concentration of oxidizer near fuel surface is developed. The numerical predictions are in very good agreements with experimental data.
Type:
text; Dissertation-Reproduction (electronic)
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Aerospace and Mechanical Engineering; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Ramohalli, Kumar

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleLarge eddy probability density function (LEPDF) simulations for turbulent reactive channel flows and hybrid rocket combustion investigations.en_US
dc.creatorYi, Jianwen.en_US
dc.contributor.authorYi, Jianwen.en_US
dc.date.issued1995en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractA new numerical simulation methodology, Large Eddy Probability Density Function (LEPDF), and corresponding numerical code have been developed for turbulent reactive flow systems. In LEPDF, large scale of turbulent motion is resolved accurately. Small scale of motion is taken care of by a modified Smagorinsky subgrid scale model. Chemical reaction terms are resolved exactly without modeling. A numerical scheme to generate inflow boundary conditions has been proposed for spatial simulations of turbulent flows. Monte-Carlo scheme is used to resolve filtered PDF (Probability Density Function) evolution equation. The present turbulent simulation code has been successfully applied in the simulations of transpired and non-transpired fully developed turbulent channel flows. It more accurately predicts turbulent channel flows than the existing temporal simulation code with only 27% of the grid size of the temporal simulation code. It has been shown that "Ejection" and "Sweep" are two dominant events in the wall region of turbulent channel flows. They are responsible for about 120% of the total turbulent production. Their interactions have negative contributions to the turbulent production, thereby keeping the total 100%. Counter-rotating vortex is a major mechanism responsible for turbulent production in boundary layer. It has also shown that injection from channel side walls increases the boundary layer thickness and turbulence intensities, but decreases the wall friction and heat transfer. Suction has opposite effects. A state-of-the-art hybrid rocket research laboratory has been established. Labscale hybrid rockets with fuel port diameters ranging from 0.5 to 4.0 inches have been designed and constructed. Rocket testing facilities for routine measurements and advanced combustion diagnosis techniques, such as infrared image technique and gas chromatography, are well developed. A computerized data acquisition/control system has been designed and built. A new Cu⁺⁺ based catalyst is identified which can improve the burning rate of general HTPB based hybrid rocket fuel by 15%. Scale-up principles are developed through a series of experimental testing on different sizes of hybrid rockets. A polymer (rocket fuel) degradation model with consideration of catalytic effects of small concentration of oxidizer near fuel surface is developed. The numerical predictions are in very good agreements with experimental data.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineAerospace and Mechanical Engineeringen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairRamohalli, Kumaren_US
dc.contributor.committeememberOrtega, Alfonsoen_US
dc.contributor.committeememberDowler, Warrenen_US
dc.identifier.proquest9603720en_US
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