Experimental and numerical study on the Effect of Mixture Composition on Vented Explosions

:: 20 Works Cited
Length: 2306 words (6.6 double-spaced pages)
Rating: Green      
Open Document
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

A parametric set of vented explosion experiments for three mixtures, stoichiometric propane-air, methane-air and 18.0 vol. % hydrogen-air were performed. The three mixtures each displayed various physical phenomena and behaviors and their similarities and differences were identified. A physics based CFD model was developed, using a small subset of the experimental data, with a single set of empirical coefficients for all three mixtures. The model takes into account the effect of turbulence, flame instabilities and the Rayleigh-Taylor instability on flame propagation and pressure generation. For cases dominated by a pressure transient associated with the external explosion, the results of the simulations show good agreement between experimental and numerical results for all three mixtures, typically within the experimental uncertainty of the experiments. Further work remains on improving the model, however, particularly to account for the pressure transient generated during structure-acoustic interactions.

Venting is a commonly used method to minimize the damage done by accidental explosions. Engineering guidelines and standards exist to estimate the minimum vent size required for a given enclosure [ ], however, these standards are not sufficiently reliable. Other approaches exist [ , ], but several issues remain unresolved due to the complex nature of the phenomena and the limited set of existing experimental data.
Historically, vented explosions have proven to be a challenge to model due to the wide range of physical phenomena present, all of which directly influence the dynamics of the process [ , ]. These phenomena include Helmholtz oscillations [4, ], the external explosion [4, ], flame instabilities [4], flam...

... middle of paper ...

...on of a flame-wrinkling LES combustion model to a turbulent mixing layer,” Proceedings of the 27th Int. Symp. on Combustion, Combustion Institute, Pittsburgh, PA, 899-907 (1998).
. Bradley, D., Gaskell, P. H. and Gu, X. J., “Burning velocities, Markstein lengths, and flame quenching for spherical methane-air flames: a computational study,” Combust. Flame 104 (2): 176-198 (1996).
. Bychkov, V., “Importance of the Darrieus-Landau Instability for Strongly Corrugated Turbulent Flames,” Physical Review E 68 (2003).
. Bradley, D., Lawes, M., Liu, K., Verhelst, S. and Woolley, R., “Laminar Burning Velocities of Lean Hydrogen–Air Mixtures at Pressures Up To 1.0 MPa,” Combust. Flame, 149: 162–172 (2007).
. Zeldovich, Y. B., Barenblatt, G. I., Librovich, V. B. and Makhviladze, G. M., Mathematical Theory of Combustion and Explosion, Consultants Bureau, New York, 1985.

Click the button above to view the complete essay, speech, term paper, or research paper

This essay is 100% guaranteed.

Title Length Color Rating  
Essay on Numerical Study of Tensile Properties of POM/ Woven Kenaf Composite. - Numerical Study of Tensile Properties of POM/ Woven Kenaf Composite. CHAPTER 1: INTRODUCTION 1.1 Background Study The geometry of woven fiber reinforced polymer like Polyoxymethylene (POM) and Woven Kenaf composite is quite complex. Therefore, to predict tensile properties of such composite requires numerical method. This project focuses on the use of The Laminator software and understanding the theories on Maximum Stress, Maximum Strain, Tsai-Hill, Hoffman, and Tsai-Wu failure to produces the required results....   [tags: woven fiber composite, geometry, ]
:: 13 Works Cited
1555 words
(4.4 pages)
Powerful Essays [preview]
The Composition of Three Types of Seaweed Essay examples - The proximate composition (protein, lipid, carbohydrate, ash and moisture) of three groups of seaweed; Green algae (Ulva lactuca and Enthromorpha intestinalis); Brown algae (Colpomenia sinuosa and Sargassum illicifolium) and Red algae (Gracilaria corticata and Hypnea valentiea) collected from the Persian Gulf coastal water were showed in table 1. Burtin, (2003) indicated that the protein content in brown algae generally is low (5-15% of the dry weight) compared with red and green algae (10-30% of dry weight), and the content also varies according to species and seasons cycle (Fleurence, 2004)....   [tags: seaweed, composition, science, experiments, ] 1768 words
(5.1 pages)
Powerful Essays [preview]
Numerical Modeling of Low Concentration Al2O3/Water Nanofluid Heat Transfer in an Annulus with Two-phase Mixture Method - The set of governing differential equations has been discretized by the control volume method. SIMPLE algorithm was used as pressure–velocity coupling technique and second order upwind method was adopted for convective and diffusive terms. The resulting algebraic system solved by using Gauss–Seidel applied in a line going through all volumes in the computational domain. Convergence criteria for all parameter were restricted to be lower than10−6. In order to achieve more accuracy grid independence studies were performed on pure water individually in each model....   [tags: temperature, pressure, efficiency] 1067 words
(3 pages)
Strong Essays [preview]
Preliminary Study on the Impacts of Variation Engineered Soil Composition - Bioretention has rapidly become one of the most versatile and widely used storm-water, best management practices (BMPs) throughout the United States and many parts of the world. It has recently become identified as a preferred site practice for green building design and leadership in energy and environmental design (LEED) certification. Despite the rapid acceptance of this BMP throughout the United States, detailed performance information and related design guidance are not currently available for many regions....   [tags: bioretention, hydraulic performance, soil types]
:: 17 Works Cited
1813 words
(5.2 pages)
Term Papers [preview]
The Army Body Composition Program Essay - ... “It’s ... awful for people who are very muscular,” says Dr. Jordan Moon, director of the Sports Science Center Research Institute in Denver. “The problem with the tape test is that it doesn’t account for muscle, it just accounts for size.” In the same article Moon states, “it wasn’t designed to test individuals but instead for large groups of healthy people” (Anderson, 2013). This, in theory, would be beneficial for being used in the military. As a leader in the military if you have a large majority of the population who needs to be taped you want an easy, cost effective way that is not time consuming and holds everyone to the same standards....   [tags: soldier´s body fat composition, analysis] 892 words
(2.5 pages)
Research Papers [preview]
Mixture and Compound Differences Essay - Mixture and Compound Differences 1 One difference between mixtures and compounds is that compounds have a certain composition as opposed to mixtures that can be varied. Chemical compounds are made up of at least two elements that are bonded together in a fixed mass ratio that can only be split apart by chemical means. And a mixture is a substance created by merging at least two different materials with no chemical reaction. Also compounds can only be separated if they are destroyed. But the elements in mixtures can be physically separated from each other easily....   [tags: Chemistry ] 634 words
(1.8 pages)
Better Essays [preview]
Numerical concepts Essay - Imagine you are sitting in your office when a little child comes bouncing in to the room, filled with curiosity. They look around the room and begin to question everything they see before their eyes fall on a large bookshelf against the wall. The little child looks at the shelf in awe, and exclaims “There must be a million books there!” Most of us who have spent time with a little kid at some point have probably heard them over exaggerate when it comes to guessing the amount of something, but not all of us have considered why this might be....   [tags: Estimating Stimuli, Mathematical Cognition]
:: 1 Works Cited
965 words
(2.8 pages)
Better Essays [preview]
Essay on Chemical Composition of Glass - Abstract Soda-based glass samples were fabricated in a laboratory scale using quartz sands that was a by-product of feldspar floatation in Tak Province, northern Thailand, and 25-wt% commercial-grade Na2CO3 as the main compositions. Fe2O3 of 0.1 to 10.0 wt% concentrations was doped into the glass mixture. Well-mixed and dried powders were melted in a ceramic crucible for 4 hr at 1250ºC using an electric furnace. Transparent and bubble-free glass samples were obtained as results. It was found that Fe2O3 dopant turned the otherwise colorless glass to dark brown....   [tags: Chemistry] 1004 words
(2.9 pages)
Strong Essays [preview]
Comparative Study of the use of the Baroque and Modern Flute in Composition - Comparative Study of the use of the Baroque and Modern Flute in Composition A comparative study of the use of the barqoue and modern flute in composition, with specific reference to -- Sonata IV for flute and continuo by J.S Bach, and Sonata for flute and piano by Hindemith The baroque, or transverse flute is of great interest to me, mainly because of my own flute playing experience. Since listening to a concert which included both a modern orchestra and a baroque orchestra playing together in a specially written composition, and separately, I have considered the baroque flute a much softer and more beautiful instrument, in construction and sound....   [tags: Papers] 1074 words
(3.1 pages)
Strong Essays [preview]
Emission-Excitation Matrices Essay - ... Despite the great potential for EEMs to increase knowledge about DOM behaviour in the environment, their interpretation and statistical treatment remain a challenge [14]. The spectral shapes of EEMs are complex mixtures of multiple and overlapping independent fluorescence phenomena, caused by the wide range of organic molecules contained in DOM. As only about 25% of these molecules have been identified (Benner2002), there is a lack of chemical standards to be used to separate the signal of bulk DOM into its individual components....   [tags: composition of fluorescent cheical mixtures] 645 words
(1.8 pages)
Research Papers [preview]