Numerical modeling of flame spread over spherical solid fuel under low speed flow in microgravity:Model development and comparison to space flight experiments

Numerical modeling of flame spread over spherical solid fuel under low speed flow in microgravity:Model development and comparison to space flight experiments

Bibliographic Details
Main Author: Endo, Makoto
Language:English
Published: Case Western Reserve University School of Graduate Studies / OhioLINK 2016
Subjects:
Mechanical Engineering
Aerospace Engineering
Numerical modeling
flame spread
solid fuel
spherical fuel
microgravity
combustion
space experiment
NASA
GEL
SoFIE
SNB-CK
Radiation
Heat transfer
Finite Element
FEM
FDS
Microgravity Experiment
NASA-STD-6001
BASS
SIFI
FSR
axisymmetric
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=case1461022358
id ndltd-OhioLink-oai-etd.ohiolink.edu-case1461022358
record_format oai_dc
collection NDLTD
language English
sources NDLTD
topic Mechanical Engineering
Aerospace Engineering
Numerical modeling
flame spread
solid fuel
spherical fuel
microgravity
combustion
space experiment
NASA
GEL
SoFIE
SNB-CK
Radiation
Heat transfer
Finite Element
FEM
FDS
Microgravity Experiment
NASA-STD-6001
BASS
SIFI
FSR
axisymmetric
spellingShingle Mechanical Engineering
Aerospace Engineering
Numerical modeling
flame spread
solid fuel
spherical fuel
microgravity
combustion
space experiment
NASA
GEL
SoFIE
SNB-CK
Radiation
Heat transfer
Finite Element
FEM
FDS
Microgravity Experiment
NASA-STD-6001
BASS
SIFI
FSR
axisymmetric
Endo, Makoto
Numerical modeling of flame spread over spherical solid fuel under low speed flow in microgravity:Model development and comparison to space flight experiments
author Endo, Makoto
author_facet Endo, Makoto
author_sort Endo, Makoto
title Numerical modeling of flame spread over spherical solid fuel under low speed flow in microgravity:Model development and comparison to space flight experiments
title_short Numerical modeling of flame spread over spherical solid fuel under low speed flow in microgravity:Model development and comparison to space flight experiments
title_full Numerical modeling of flame spread over spherical solid fuel under low speed flow in microgravity:Model development and comparison to space flight experiments
title_fullStr Numerical modeling of flame spread over spherical solid fuel under low speed flow in microgravity:Model development and comparison to space flight experiments
title_full_unstemmed Numerical modeling of flame spread over spherical solid fuel under low speed flow in microgravity:Model development and comparison to space flight experiments
title_sort numerical modeling of flame spread over spherical solid fuel under low speed flow in microgravity:model development and comparison to space flight experiments
publisher Case Western Reserve University School of Graduate Studies / OhioLINK
publishDate 2016
url http://rave.ohiolink.edu/etdc/view?acc_num=case1461022358
work_keys_str_mv AT endomakoto numericalmodelingofflamespreadoversphericalsolidfuelunderlowspeedflowinmicrogravitymodeldevelopmentandcomparisontospaceflightexperiments
_version_ 1719439545208930304
spelling ndltd-OhioLink-oai-etd.ohiolink.edu-case14610223582021-08-03T06:35:45Z Numerical modeling of flame spread over spherical solid fuel under low speed flow in microgravity:Model development and comparison to space flight experiments Endo, Makoto Mechanical Engineering Aerospace Engineering Numerical modeling flame spread solid fuel spherical fuel microgravity combustion space experiment NASA GEL SoFIE SNB-CK Radiation Heat transfer Finite Element FEM FDS Microgravity Experiment NASA-STD-6001 BASS SIFI FSR axisymmetric Flame spread over solid fuel presents distinctive characteristics in reduced gravity, especially when the forced flow velocity is low. The lack of buoyancy allows a blue, dim flame to sustain where the induced velocity would otherwise blow it off. At such low velocities, a quenching limit exists where the soot content is low and the effect of radiative heat loss becomes important. The objective of this study is to establish a high fidelity numerical model to simulate the growth and extinction of flame on solid fuels in a reduced gravity environment. The great importance of the spectral dependency of the gas phase absorption and emission were discovered through the model development and therefore, Statistical Narrow-Band Correlated-k (SNB-CK) spectral model was implemented.The model is applied to an experimental configuration from the recent space experiment, Burning And Suppression of Solids (BASS) project conducted aboard the International Space Station. A poly(methyl methacrylate) (PMMA) sphere (initial diameter of 2cm) was placed in a small wind tunnel (7.6cm x 7.6cm x 17cm) within the Microgravity Science Glovebox where flow speed and oxygen concentration were varied.Data analysis of the BASS experiment is also an important aspect of this research, especially because this is the first space experiment that used thermally thick spherical samples. In addition to the parameters influencing the flammability of thin solids, the degree of interior heat-up becomes an important parameter for thick solids. For spherical samples, not only is the degree of internal heating constantly changing, but also the existence of stagnation point, shoulder, and wake regions resulting in a different local flow pattern, hence a different flame-solid interaction.Parametric studies using the numerical model were performed against (1) chemical reaction parameters, (2) forced flow velocity, (3) oxygen concentration and (4) amount of preheating (bulk temperature of the solid fuel). Flame Spread Rate (FSR) was used to evaluate the transient effect and maximum flame temperature, standoff distance and radiative loss ratio were used to evaluate the spontaneous response of the gas phase to understand the overall response of the burning solid fuel. After evaluating the individual effect of each parameter, the efficacy of each parameter was compared. Selected results of this research are:[1]Experimental data from BASS and numerical simulation both showed that within the time periodbetween ignition until the flame tip reaches the shoulder of the sample, the flame length and timehave almost a linear relation.[2]Decreasing forced flow velocity increases the radiative loss ratio whereas decreasing oxygen molefraction decreases the radiative loss ratio. This finding must be considered in the effort to replicatethe behavior of flame spread over thick solid fuels in microgravity on earth.[3]Although the standoff distance will increase when the forced flow velocity is decreased as well aswhen the oxygen mole fraction is decreased, the forced flow velocity has a much stronger effect onthe standoff distance than the oxygen mole fraction.[4]Unlike the previous two comparisons, the effect of forced flow velocity and oxygen mole fraction onthe maximum flame temperature was at similar level, reduction of either parameter would result inlowering the maximum flame temperature.[5]The effect of preheating on the flame spread rate becomes stronger when either the oxygen flowrate or forced flow velocity becomes larger. Depending on which element is more important, we candistinguish oxygen flow rate driven flame spread from preheating driven flame spread.Findings of this research are being utilized in the design of the upcoming space experiment, Growth and Extinction Limits of solid fuel (GEL) project. This research is supported by the National Aeronautics and Space Administration (NASA). This work made use of the High Performance Computing Resource in the Core Facility for Advanced Research Computing at Case Western Reserve University and the Ohio Supercomputer Center. 2016-05-31 English text Case Western Reserve University School of Graduate Studies / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=case1461022358 http://rave.ohiolink.edu/etdc/view?acc_num=case1461022358 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

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