Modeling of Boiling Liquid Expanding Vapor Explosion (BLEVE): Plane, Cylindrical and Spherical 1D Model

2008 ◽  
Author(s):  
G. A. Pinhasi ◽  
Y. Dahan ◽  
A. Dayan ◽  
A. Ullmann
Keyword(s):  
Shock Wave ◽  
Current Model ◽  
Dynamic State ◽  
Vapor Explosion ◽  
Two Phase ◽  
Boiling Liquid ◽  
Energy Models ◽  
Model Predictions ◽  
1D Model ◽  
Tnt Equivalence

A 1D plane, cylindrical and spherical numerical model was developed for estimating the thermodynamic and the dynamic state of the boiling liquid during a boiling liquid expanding vapor explosion (BLEVE) event. The model predicts, simultaneously, the flow properties of the expanding two-phase flashing mixture and its surrounding air. The possible presence of a shock wave formed by the fluid expansion through the air is accounted for in the model. Model predictions of the shock wave strengths, in terms of TNT equivalence for the various coordinate systems, were compared against those obtained by simple energy models. As expected, the simple energy models over predicts the shock wave strength. However, the simple model which accounts for the expansion irreversibility, produces results which are closer to current model predictions. For the 1D plane case the model simulates a BLEVE scenario in a tunnel, whereas for the spherical case the more realistic BLEVE scenario in free space is being studied.

Novel Solutions in Modeling of Anaerobic Digestion Process - Two-Phase AD Models Development and Comparison

2018 ◽  
Vol 16 (8) ◽  
Author(s):  
Karol Postawa
Keyword(s):  
Anaerobic Digestion ◽  
Process Model ◽  
Large Scale ◽  
Reference Model ◽  
Biogas Production ◽  
Current Model ◽  
Pilot Scale ◽  
Two Phase ◽  
Novel Approach ◽  
Model Predictions

Abstract This work focuses on Two Phase Anaerobic Digestion – a novel approach to split reactions’ chain in two separated tanks, each with specialized microbe community to achieve the best possible efficiency for each part of conversion. More specifically, the article tackle the topic of evaluation the possibility to adapt a mathematical model, previously dedicated for Autogenerative High Pressure Digestion (AHPD), to make use of it in simulation of Temperature Phased Anaerobic Digestion (TPAD) process. A comprehensive study of available solutions for biogas production simulation in conventional and TPAD configuration is additionally performed. Basing on its results, a reference model from literature, for comparison purpose is selected. Revisions and modifications, necessary to adjust previously developed model, to TPAD process, are described. Also, additional improvements like redesigned pH calculating algorithm is presented. Finally, the comparison between model predictions, a reference model and pilot-scale data is carried out. The results show that our current model needs further optimization, however even at this stage it provides acceptable results in short-range simulations (not longer than 42 days). Further works should focus on process stability improvement, especially in the thermophilic stage of biogas production. There's an opportunity for innovation as the research shows that requirement of accurate, large-scale optimized TPAD process model, is still not fulfilled.

The Numerical Modeling of Spherical Explosion in the Foam

2016 ◽  
Vol 11 (1) ◽  
pp. 60-65 ◽  
Author(s):  
R.Kh. Bolotnova ◽  
E.F. Gainullina
Keyword(s):  
Shock Wave ◽  
Numerical Modeling ◽  
Initial Pressure ◽  
Water Volume ◽  
Symmetric Model ◽  
Two Phase ◽  
Experimental Conditions ◽  
Initial Water ◽  
Aqueous Foam ◽  
Spherical Explosion

The spherical explosion propagation process in aqueous foam with the initial water volume content α10=0.0083 corresponding to the experimental conditions is analyzed numerically. The solution method is based on the one-dimensional two-temperature spherically symmetric model for two-phase gas-liquid mixture. The numerical simulation is built by the shock capturing method and movable Lagrangian grids. The amplitude and the width of the initial pressure pulse are found from the amount of experimental explosive energy. The numerical modeling results are compared to the real experiment. It’s shown, that the foam compression in the shock wave leads to the significant decrease in velocity and in amplitude of the shock wave.

Features of spatial shock-wave flows in vapor-gas-liquid mixtures

2014 ◽  
Vol 10 ◽  
pp. 27-31
Author(s):  
R.Kh. Bolotnova ◽  
U.O. Agisheva ◽  
V.A. Buzina
Keyword(s):  
Shock Wave ◽  
High Pressure ◽  
Shock Waves ◽  
Liquid Mixture ◽  
Liquid Mixtures ◽  
Pressure Vessels ◽  
Water Mixture ◽  
Two Dimensional ◽  
Nonstationary Processes ◽  
Two Phase

The two-phase model of vapor-gas-liquid medium in axisymmetric two-dimensional formulation, taking into account vaporization is constructed. The nonstationary processes of boiling vapor-water mixture outflow from high-pressure vessels as a result of depressurization are studied. The problems of shock waves action on filled by gas-liquid mixture volumes are solved.

Storage Battery Explosions: Heating and Jarring

1986 ◽  
Vol 3 (2) ◽  
Author(s):  
Harry S. Dixon
Keyword(s):  
High Rate ◽  
Storage Battery ◽  
High Current ◽  
Vapor Explosion ◽  
Popular Belief ◽  
Boiling Liquid ◽  
Localized Heating ◽  
A Cell ◽  
Current Drain

A previous paper entitled Storage Battery Explosions: Hydrogen or BLEVE.? showed that contrary to popular belief storage battery explosions concurrent with or following a high rate of discharge were BLEVE (Boiling Liquid Expanding Vapor Explosion) explosions rather than hydrogen. The bases of that paper were the explosions of two batteries. Because of low liquid in a cell there had been excessive localized heating, actually superheating, between the plates. However, other than the explosion resulting from alleged superheating there was no other indication nor evidence of heating. This paper describes a BLEVE explosion that resulted simply from jarring after the overheating of the battery which had been subjected to high current drain in attempting to start the automobile. It is referred to as the Salaam case.

scholarly journals A Two-Phase Model of Air Shock Wave Induced by Rock-Fall in Closed Goaf

2017 ◽  
Author(s):  
Fengyu Ren ◽  
Yang Liu ◽  
Jianli Cao ◽  
Rongxing He ◽  
Yuan Xu ◽  
...  
Keyword(s):  
Shock Wave ◽  
Theoretical Analysis ◽  
Phase Model ◽  
Rock Fall ◽  
Uniform Motion ◽  
Two Phase ◽  
Protective Measures ◽  
Computational Fluid Dynamics Cfd ◽  
Series Of Experiments ◽  
Wave Induced

In this paper, a two-phase model of air shock wave induced by rock-fall was described. The model was made up of the uniform motion phase (velocity was close to 0 m·s-1) and the acceleration movement phase. The uniform motion phase was determined by experience, meanwhile the acceleration movement phase was derived by the theoretical analysis. A series of experiments were performed to verify the two-phase model and obtained the law of the uniform motion phase. The acceleration movement phase was taking a larger portion when height of rock-fall was higher with the observations. Experimental results of different falling heights showed good agreements with theoretical analysis values. Computational fluid dynamics (CFD) numerical simulation had been carried out to study the variation velocity with different falling height. As a result of this, the two-phase model could accurately and convenient estimating the velocity of air shock wave induced by rock-fall. The two-phase model could provide a reference and basis for estimating the air shock waves' velocity and designing the protective measures.

Strain Gradient Plasticity Theory Based on Dislocation - Controlling Mechanism for Nanocrystalline Materials

2010 ◽  
Vol 97-101 ◽  
pp. 2155-2158
Author(s):  
Jian Qiu Zhou ◽  
Lu Ma ◽  
Rong Tao Zhu
Keyword(s):  
Strain Gradient ◽  
Plasticity Theory ◽  
Strain Gradient Plasticity ◽  
Gradient Plasticity ◽  
Two Phase ◽  
Grain Sizes ◽  
Controlling Mechanism ◽  
Model Predictions ◽  
Theory Comparison ◽  
Strain Gradient Plasticity Theory

Due to their dissimilar properties and different deformation mechanisms between grain interior (GI) and grain boundary affected zone (GBAZ) in the nanocrystalline (NC) materials, a two-phase composite model consisting of GI and GBAZ was developed and adopted to build strain gradient plasticity theory. Comparison between experimental data and model predictions at different grain sizes for NC copper shows that the developed method appears to be capable of describing the strain hardening of NC materials.

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