Utilizing prior information in the estimation of volume fraction distribution

The present work concerns the simulation of metallurgical evolutions in 3D multi-pass forming processes. In this context, the analyzed problem is twofold. One point refers to the management of the microstructure evolution during each pass or each inter-pass period and the other point concerns the management of the multi-pass aspects (different grain categories, data structure). In this framework, a model is developed and deals with both aspects. The model considers the microstructure as a composite made of a given (discretized) number of phases which have their own specific properties. The grain size distribution and the recrystallized volume fraction distribution of the different phases evolve continuously during a pass or inter-pass period. With this approach it is possible to deal with the heterogeneity of the microstructure and its evolution in multi-pass conditions. Both dynamic and static recrystallization phenomena are taken into account, with typical Avrami-type equations. The present model is implemented in the Finite Element code FORGE2005®. 3D numerical simulation results for a multi-pass process are presented.

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Gas Distribution Law for the Fully Mechanized Top-Coal Caving Face in a Gassy Extra-Thick Coal Seam

Advances in Civil Engineering ◽

10.1155/2018/3563728 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8

Author(s):

Wenlin Wang ◽

Fangtian Wang ◽

Bin Zhao ◽

Gang Li

Keyword(s):

Longwall Mining ◽

Volume Fraction ◽

Vertical Direction ◽

Thick Coal Seam ◽

Working Face ◽

Coal Wall ◽

The Face ◽

Fraction Distribution ◽

Gas Volume Fraction ◽

Gas Volume

Mine gas overflow is a serious threat to the safe and efficient longwall mining of gassy coal seams. Based on the field mining conditions and gas extraction of the fully mechanized top-coal caving face of a gassy coal mine, the space volume fraction distribution and emission (extraction rate) of gas in the face were tested by an arrangement of measuring points in the stereo grid. The isograms of gas volume fraction distribution for each measurement section and air direction in the face are drawn. The research shows that each measurement section gas volume fraction distribution is presented for an asymmetric concave curve along the vertical direction of the coal wall in the air-inlet side and the air-return side of the face; on the working face air-return side, the determination of gas volume fraction distribution of the section appears as falling straight line along the vertical direction of the coal wall. Before the first weighting, the absolute quantity of gas emission in the working face increased with the advancing of the working face, reached the maximum at the time of the first weighting, and then remained stable.

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The Correlation of Drop-Size Distributions in Fuel Nozzle Sprays—Part I: The Drop-Size/Volume-Fraction Distribution

Journal of Engineering for Power ◽

10.1115/1.3446488 ◽

1977 ◽

Vol 99 (3) ◽

pp. 309-314 ◽

Cited By ~ 81

Author(s):

H. C. Simmons

Keyword(s):

Drop Size ◽

Volume Fraction ◽

Operating Conditions ◽

Different Types ◽

Median Diameter ◽

Fraction Distribution ◽

Fuel Nozzle ◽

Drop Size Distributions ◽

Mass Median ◽

Mass Median Diameter

The paper presents data on the drop-size/volume-fraction distributions of sprays observed with a large number of gas-turbine fuel nozzles of different types including both pressure and air-atomizers, using a range of fuel viscosities, at a variety of operating conditions. The data were obtained by both optical and wax-droplet methods. It is shown that a universal nondimensional correlation can be established for all the fuel nozzles when the drop-size is normalized to the mass median diameter. The correlation enables prediction of the drop-size/volume-fraction distribution for a spray given only the mass median or Sauter mean diameter.

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On the Role of Enduring Contact in Powder Lubrication

Journal of Tribology ◽

10.1115/1.2114933 ◽

2005 ◽

Vol 128 (1) ◽

pp. 168-175 ◽

Cited By ~ 18

Author(s):

J. Y. Jang ◽

M. M. Khonsari

Keyword(s):

Analytical Solution ◽

Flow Velocity ◽

Volume Fraction ◽

Flow Characteristics ◽

Kinetic Regime ◽

Governing Equations ◽

Wide Range ◽

Fraction Distribution ◽

Powder Lubrication

This paper is devoted to a study of the enduring contact between granules of powder lubricants in an effort to better understand the flow characteristics of powder lubricants. Appropriate formulation of the governing equations is reported that can be used for prediction of the flow velocity, pseudo temperature, and volume fraction distribution of powders for a wide range of operating speeds. A set of parametric simulations and a limiting analytical solution is presented for predicting the behavior of a powder lubricant under low operating speeds when the enduring contact tends to dominate the kinetic regime. The limiting solution shows that below a certain sliding speed the volume fraction remains unchanged due to the effect of the enduring contact. It is also shown that below this limiting speed the enduring contact plays a major role and should not be neglected.

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Curing of Thick Angle-Bend Thermoset Composite Part: Curing Process Modification for Uniform Thickness and Uniform Fiber Volume Fraction Distribution

Journal of Composite Materials ◽

10.1106/f97f-u8rd-qyn8-q8ju ◽

2000 ◽

Vol 34 (20) ◽

pp. 1710-1755 ◽

Cited By ~ 18

Author(s):

Malak I. Naji ◽

Suong V. Hoa

Keyword(s):

Fiber Volume Fraction ◽

Volume Fraction ◽

Curing Process ◽

Uniform Thickness ◽

Fiber Volume ◽

Composite Part ◽

Process Modification ◽

Fraction Distribution ◽

Angle Bend

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Lubrication With Binary Mixtures: Liquid-Liquid Emulsion in an EHL Conjunction

Journal of Tribology ◽

10.1115/1.2921668 ◽

1993 ◽

Vol 115 (3) ◽

pp. 515-522 ◽

Cited By ~ 21

Author(s):

S. H. Wang ◽

A. Al-Sharif ◽

K. R. Rajagopal ◽

A. Z. Szeri

Keyword(s):

Binary Mixtures ◽

Volume Fraction ◽

Liquid Mixtures ◽

Important Application ◽

Solid Surfaces ◽

Oil In Water ◽

Liquid Emulsion ◽

Fraction Distribution ◽

Oil Emulsions ◽

Liquid Binary Mixtures

Oil-in-water and water-in-oil emulsions are often employed as lubricants. In many applications of emulsion lubricants both the deformation of the bounding solid surfaces and the pressure dependence of the viscosity of the lubricant contribute essentially to performance, thus defining lubrication in the elastohydrodynamic (EHD) mode. In this paper we investigate lubrication with liquid-liquid binary mixtures of two Newtonian fluids in an EHD conjunction, and discuss the effect of varying the parameters of the problem on pressure, film thickness and volume fraction distribution. The basic theory of lubrication with liquid-liquid mixtures is contained in an earlier publication (Al-Sharif et al., 1992), here we use the theory to study an important application.

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