國立虎尾科技大學 |

Characterization of the Interface Between Detonation Product Gases and Ambient Air in an Explosion.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Characterization of the Interface Between Detonation Product Gases and Ambient Air in an Explosion./
Author:	Peterson, Christian.
Description:	1 online resource (172 pages)
Notes:	Source: Dissertations Abstracts International, Volume: 85-06, Section: B.
Contained By:	Dissertations Abstracts International85-06B.
Subject:	Fluid mechanics. -
Online resource:	click for full text (PQDT)
ISBN:	9798381160376

Characterization of the Interface Between Detonation Product Gases and Ambient Air in an Explosion.
Peterson, Christian.

Characterization of the Interface Between Detonation Product Gases and Ambient Air in an Explosion. - 1 online resource (172 pages)

Source: Dissertations Abstracts International, Volume: 85-06, Section: B.

Thesis (Ph.D.)--New Mexico Institute of Mining and Technology, 2024.

Includes bibliographical references

Characterization of the interface between detonation product gases and ambient air in an explosion is a complicated task due to turbulent mixing and the inherently three-dimensional expansion of the interface. This study aimed to quantify the evolution of the interface complexity and progression to turbulence as a temporally-varying fractal. Laboratory and field scale experiments were conducted to identify characteristics of an explosively driven gas cloud such as the growth as a function of time and the width of the mixing region during expansion. Experiments were conducted using several explosives in primarily spherical geometries.In the laboratory-scale work, a shotgun primer was used to generate a repeatable explosively-driven gas cloud in varying confinement. High speed imaging captured the evolution of the product gas interface, and an automated image processing routine extracted and measured the mixing region width h. A comparison was made to a gas cloud radius based predictive model for the width of the mixing region, and a new scaling factor k was used to scale the equations for a non-zero start time. The fitting parameters c and k were found to vary with the degree of confinement as the experimental conditions diverged from the base assumptions of the model. No particular trends were found in the evolution of k, though for early times the geometric constraint c was seen to increase disproportionately with k as spacing increases. The model was also applied to mixing region growth on spherical explosive charges with known initial surface perturbations. It was found that the width of the mixing region is predicted by the analytical model at the initial stages of the blast, but transitions to non-linear turbulent mixing before the shock has detached from the fireball.In laboratory and field-scale experiments, the Hausdorff or fractal dimension of two-dimensional slices of the explosively driven gas cloud was measured from multiple angles. Gas cloud profiles representing the contact surface were extracted using automated image processing algorithms. The Hausdorff dimension was estimated using a box counting algorithm on the extracted contours. Experiments were performed with charge mass variations to identify scaling for the Hausdorff dimension, as well as other fireball characteristics such as radius. The fractal dimension was found to not scale with shock scaling laws once the shock has detached from the fireball. Taken as a function of mixing region width, the fractal dimension was seen to begin increasing as the validity of the analytical models ends, indicating an increase in the non-linear turbulence that drives complexity on the surface of the fireball.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2024

Mode of access: World Wide Web

ISBN: 9798381160376Subjects--Topical Terms:

555551
Fluid mechanics.
Subjects--Index Terms:

Spherical explosive Index Terms--Genre/Form:

554714
Electronic books.

Characterization of the Interface Between Detonation Product Gases and Ambient Air in an Explosion.
LDR:04150ntm a22004097 4500 001 1143671
005 20240517104626.5
006 m o d
007 cr mn ---uuuuu
008 250605s2024 xx obm 000 0 eng d
020 $a 9798381160376
035 $a (MiAaPQ)AAI30696228
035 $a AAI30696228
040 $a MiAaPQ $b eng $c MiAaPQ $d NTU
100 1 $a Peterson, Christian. $3 1468428
245 1 0 $a Characterization of the Interface Between Detonation Product Gases and Ambient Air in an Explosion.
264 0 $c 2024
300 $a 1 online resource (172 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertations Abstracts International, Volume: 85-06, Section: B.
500 $a Advisor: Hargather, Michael.
502 $a Thesis (Ph.D.)--New Mexico Institute of Mining and Technology, 2024.
504 $a Includes bibliographical references
520 $a Characterization of the interface between detonation product gases and ambient air in an explosion is a complicated task due to turbulent mixing and the inherently three-dimensional expansion of the interface. This study aimed to quantify the evolution of the interface complexity and progression to turbulence as a temporally-varying fractal. Laboratory and field scale experiments were conducted to identify characteristics of an explosively driven gas cloud such as the growth as a function of time and the width of the mixing region during expansion. Experiments were conducted using several explosives in primarily spherical geometries.In the laboratory-scale work, a shotgun primer was used to generate a repeatable explosively-driven gas cloud in varying confinement. High speed imaging captured the evolution of the product gas interface, and an automated image processing routine extracted and measured the mixing region width h. A comparison was made to a gas cloud radius based predictive model for the width of the mixing region, and a new scaling factor k was used to scale the equations for a non-zero start time. The fitting parameters c and k were found to vary with the degree of confinement as the experimental conditions diverged from the base assumptions of the model. No particular trends were found in the evolution of k, though for early times the geometric constraint c was seen to increase disproportionately with k as spacing increases. The model was also applied to mixing region growth on spherical explosive charges with known initial surface perturbations. It was found that the width of the mixing region is predicted by the analytical model at the initial stages of the blast, but transitions to non-linear turbulent mixing before the shock has detached from the fireball.In laboratory and field-scale experiments, the Hausdorff or fractal dimension of two-dimensional slices of the explosively driven gas cloud was measured from multiple angles. Gas cloud profiles representing the contact surface were extracted using automated image processing algorithms. The Hausdorff dimension was estimated using a box counting algorithm on the extracted contours. Experiments were performed with charge mass variations to identify scaling for the Hausdorff dimension, as well as other fireball characteristics such as radius. The fractal dimension was found to not scale with shock scaling laws once the shock has detached from the fireball. Taken as a function of mixing region width, the fractal dimension was seen to begin increasing as the validity of the analytical models ends, indicating an increase in the non-linear turbulence that drives complexity on the surface of the fireball.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2024
538 $a Mode of access: World Wide Web
650 4 $a Fluid mechanics. $3 555551
650 4 $a Engineering. $3 561152
650 4 $a Optics. $3 595336
650 4 $a Mechanical engineering. $3 557493
653 $a Spherical explosive
653 $a Fractal dimension
653 $a Mixing region
653 $a Turbulence
653 $a Ambient air
655 7 $a Electronic books. $2 local $3 554714
690 $a 0204
690 $a 0752
690 $a 0537
690 $a 0548
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a New Mexico Institute of Mining and Technology. $b Mechanical Engineering. $3 1179015
773 0 $t Dissertations Abstracts International $g 85-06B.
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=30696228 $z click for full text (PQDT)