Investigation of the kinetics of breakup of gas bubbles in liquid metals with digital simulation method

1987 ◽  
Vol 58 (9) ◽  
pp. 414-420 ◽  
Author(s):  
Saffet Turkan ◽  
Klaus W. Lange
Keyword(s):  
Liquid Metals ◽  
Digital Simulation ◽  
Gas Bubbles ◽  
Simulation Method ◽  
Kinetics Of

Distorted gas bubbles at large Reynolds number

1974 ◽  
Vol 62 (1) ◽  
pp. 163-183 ◽  
Author(s):  
M. El Sawi
Keyword(s):  
Surface Tension ◽  
Weber Number ◽  
Liquid Metals ◽  
Gas Bubbles ◽  
Joint Effect ◽  
Large Reynolds Number ◽  
Recent Experimental Data ◽  
Approximate Theory ◽  
Axis Ratio ◽  
Comparison Of The Results

The distortion of a gas bubble rising steadily in an inviscid incompressible liquid of infinite extent under the action of surface tension forces is investigated theoretically using an appropriate extension of the tensor virial theorem. A convenient parameter for distinguishing the bubble shape is the Weber numberW. The virial method leads to an expression relatingWand the axis ratio χ, of the transverse and longitudinal axes of the bubble. To first order inW, this relation agrees with the linear theory established by Moore (1959). Also, comparison of the results with his (1965) approximate theory reveals similar features and excellent agreement up to χ = 2. In particular, it confirms his prediction of the existence of a maximum Weber number. Although the present work does not consider the stability of these bubbles, it is interesting to note that the maximum value of 3.271 attained byWdiffers only by about 2.8% from the critical Weber number obtained by Hartunian & Sears (1957) for the onset of instability.An approximate method for the study of slightly distorted spheroidal gas bubbles is also formulated and the resulting boundary-value problem solved numerically. The theory is then extended to include gravity. The joint effect of surface tension as well as gravitational forces has not been included in earlier theories. The shapes of the bubbles are traced and compared with the unperturbed spheroids. Comparisons for the velocity of bubble rise are made between the present predictions and some experimental results. In particular the results are compared with recent experimental data for the motion of gas bubbles in liquid metals.

scholarly journals Bioactive molecules modelised by numerical simulation:molecules against Escherichia Coli

2014 ◽  
Vol 70 (a1) ◽  
pp. C1008-C1008
Author(s):  
Rita Kakou Yao ◽  
Jules Abodou Tenon ◽  
Akoun Abou
Keyword(s):  
Escherichia Coli ◽  
Biological Activity ◽  
In Silico ◽  
Biological Activities ◽  
Digital Simulation ◽  
Simulation Method ◽  
Bioactive Molecules ◽  
Structural Determination ◽  
Human Beings

The work exposed in this paper joins in the research of medecine by means of the modelling by digital simulation (method in silico). This method allows to plan the biological activities of new molecules and to design others more active than existing molecules against a given infection . The generated and validated models are used here in the research for molecules potentially more active against Escherichia coli which causes diarrheic infections at the human beings. Here, we report works the synthesis of our works of structural determination, of forecast of biological activity and conception of molecules bioactive again Eschericha coli.

A Simulation Method of Establishing Fatigue Life Distribution

1976 ◽  
Vol 98 (1) ◽  
pp. 183-188 ◽  
Author(s):  
H. A. Elmaraghy ◽  
J. N. Siddall
Keyword(s):  
Fatigue Life ◽  
Material Properties ◽  
Digital Simulation ◽  
Simulation Method ◽  
Fatigue Tests ◽  
Design Tool ◽  
Statistical Characteristics ◽  
Life Distribution ◽  
Parametric Studies ◽  
Life Distributions

This paper presents a Monte Carlo simulation method for fatigue failure, by which the randomness of two material properties as well as that of the applied load can be incorporated into a stochastic model using an appropriate failure criterion to predict the statistical characteristics of fatigue life under constant and random amplitude cyclic loading conditions. In this technique, both the endurance limit Se and the fatigue strength coefficient Sf′ are treated as stochastic variables. The combined effect of the randomness of Se, Sf′, and the applied stress on the statistical characteristics of fatigue lives is predicted analytically using digital simulation of fatique tests. The life distributions and their statistical characteristics are found to be in good agreement with those obtained from analyzing the experimental results, indicating that the proposed technique and the underlying assumptions and hypotheses are adequate. The suggested method is believed to be an effective, fast, and easy-to-use design tool which is suitable for use on electronic computers. It is ideal for parametric studies compared with the costly and time-consuming laboratory fatigue tests. Minimum experimental data are needed as a basis for the analysis. New results are presented which show the effect of the randomness of the loads and material properties on the randomness of fatigue life distribution.

A Study on the Numerical Simulation Method for the NC Incremental Sectional Forming

2014 ◽  
Vol 988 ◽  
pp. 241-244
Author(s):  
Hu Zhu ◽  
Wen Wen Lin ◽  
Jin Lan Bai
Keyword(s):  
Numerical Simulation ◽  
Digital Simulation ◽  
Simulation Method ◽  
Forming Quality ◽  
Numerical Simulation Method ◽  
Simulation Results ◽  
The Difference

The digital simulation method for NC incremental sectional forming is studied and the forming effect of NC incremental integral forming and sectional forming is analyzed through the digital simulation method in this paper. Digital simulation results show that the proposed simulation method for NC incremental sectional forming is reasonable and achievable. The difference of the forming quality between NC incremental sectional forming and integral forming is small. The sectional forming method has feasibility.

Determination of the kinetics of dissolution of materials in liquid metals

1968 ◽  
Vol 2 (5) ◽  
pp. 411-413 ◽  
Author(s):  
V. N. Eremenko ◽  
Ya. V. Natanzon
Keyword(s):  
Liquid Metals ◽  
Kinetics Of Dissolution ◽  
Kinetics Of

scholarly journals Cotranscriptional kinetic folding of RNA secondary structures

2020 ◽  
Author(s):  
Vo Hong Thanh ◽  
Pekka Orponen
Keyword(s):  
Structure Formation ◽  
Rna Structure ◽  
Rna Folding ◽  
Computational Prediction ◽  
Simulation Method ◽  
Rna Structures ◽  
Rna Molecules ◽  
Primitive Operation ◽  
Nucleotide Resolution ◽  
Kinetics Of

Computational prediction of RNA structures is an important problem in computational structural biology. Studies of RNA structure formation often assume that the process starts from a fully synthesized sequence. Experimental evidence, however, has shown that RNA folds concurrently with its elongation. We investigate RNA structure formation, taking into account also the cotranscriptional effects. We propose a single-nucleotide resolution kinetic model of the folding process of RNA molecules, where the polymerase-driven elongation of an RNA strand by a new nucleotide is included as a primitive operation, together with a stochastic simulation method that implements this folding concurrently with the transcriptional synthesis. Numerical case studies show that our cotranscriptional RNA folding model can predict the formation of metastable conformations that are favored in actual biological systems. Our new computational tool can thus provide quantitative predictions and offer useful insights into the kinetics of RNA folding.

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