A probability model for predicting the slip velocity of large particles in vertical pipes

2022 ◽  
pp. 117102
Author(s):  
Deping Sun ◽  
Haixiao Liu
Keyword(s):  
Slip Velocity ◽  
Probability Model ◽  
Large Particles

Measurement of Velocities in Two-Phase Flow by Laser Velocimetry: Interaction Between Solid Particles’ Motion and Turbulence

2008 ◽  
Vol 130 (7) ◽  
Author(s):  
N. Sad Chemloul ◽  
O. Benrabah
Keyword(s):  
Slip Velocity ◽  
Continuous Phase ◽  
Solid Particles ◽  
Homogeneous Fluid ◽  
Two Phase ◽  
Laser Anemometry ◽  
Kolmogorov Length Scale ◽  
Liquid Suspension ◽  
Large Particles ◽  
Solid Liquid

In this work, an experimental method based on laser anemometry with Doppller effects is developed. This allows the measurement of velocities and their fluctuations in a flow of solid-liquid suspension in an ascendant vertical pipe. In order to distinguish between the signals coming from the continuous phase, water, and those of the glass bead particles larger than the Kolmogorov length scale, an electronic logic circuit was incorporated in the measuring equipment. This enabled the study of both the slip velocity of the solid-liquid suspension and the influence of the large particles on turbulence. The results show that a fine particle suspension, which represents a tracer, behaves as a homogeneous fluid. For large particles, we confirmed the existence of a slip velocity and the effect of particle size on the turbulence. The use of two distinct measurement volumes produces good results for the direct measurement of the turbulent length scales. The results show that the presence of solid particles modifies the turbulence characteristics.

The wustite-spinel interface

1987 ◽  
Vol 45 ◽  
pp. 268-269
Author(s):  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Strain Energy ◽  
Matrix Material ◽  
Lattice Misfit ◽  
Solid State Reactions ◽  
Oxygen Sublattice ◽  
Large Particles ◽  
Small Lattice ◽  
Coherent Interfaces

The wustite-spinel interface can be viewed as a model interface because the wustite and spinel can share a common f.c.c. oxygen sublattice such that only the cations distribution changes on crossing the interface. In this study, the interface has been formed by a solid state reaction involving either external or internal oxidation. In systems with very small lattice misfit, very large particles (>lμm) with coherent interfaces have been observed. Previously, the wustite-spinel interface had been observed to facet on {111} planes for MgFe2C4 and along {100} planes for MgAl2C4 and MgCr2O4, the spinel then grows preferentially in the <001> direction. Reasons for these experimental observations have been discussed by Henriksen and Kingery by considering the strain energy. The point-defect chemistry of such solid state reactions has been examined by Schmalzried. Although MgO has been the principal matrix material examined, others such as NiO have also been studied.

Advances in ultramicrotomy for physical sciences applications

1993 ◽  
Vol 51 ◽  
pp. 710-711
Author(s):  
G. McMahon ◽  
T. Malis
Keyword(s):  
Particle Surface ◽  
Zeolite Catalysts ◽  
Physical Sciences ◽  
Pull Out ◽  
Large Particles ◽  
Novel Applications ◽  
Metal Wires ◽  
Frequent Problem ◽  
Specific Orientation ◽  
Diamond Knife

As with all techniques which are relatively new and therefore underutilized, diamond knife sectioning in the physical sciences continues to see both developments of the technique and novel applications.Technique Developments Development of specific orientation/embedding procedures for small pieces of awkward shape is exemplified by the work of Bradley et al on large, rather fragile particles of nuclear waste glass. At the same time, the frequent problem of pullout with large particles can be reduced by roughening of the particle surface, and a proven methodology using a commercial coupling agent developed for glasses has been utilized with good results on large zeolite catalysts. The same principle (using acid etches) should work for ceramic fibres or metal wires which may only partially pull out but result in unacceptably thick sections. Researchers from the life sciences continue to develop aspects of embedding media which may be applicable to certain cases in the physical sciences.

Analysis of Rough Porous Inclined Slider Bearing Lubricated With a Ferrofluid Considering Slip Velocity

2019 ◽  
Vol 7 (1) ◽  
pp. 387-396 ◽  
Author(s):  
Mohmmadraiyan M. Munshi ◽  
Ashok R. Patel ◽  
Gunamani Deheri
Keyword(s):  
Slip Velocity ◽  
Slider Bearing

Probability model for control parameters in the aircraft's information and control systems

2018 ◽  
Vol 2 ◽  
pp. 9-16
Author(s):  
A. Al-Ammouri ◽  
◽  
H.A. Al-Ammori ◽  
A.E. Klochan ◽  
A.M. Al-Akhmad ◽  
...  
Keyword(s):  
Control Systems ◽  
Probability Model ◽  
Control Parameters ◽  
And Control

Prediction of Tread Pattern Wear by an Explicit Finite Element Model3

2007 ◽  
Vol 35 (4) ◽  
pp. 276-299 ◽  
Author(s):  
J. C. Cho ◽  
B. C. Jung
Keyword(s):  
Finite Element ◽  
Wear Rate ◽  
Tangential Stress ◽  
Rate Equation ◽  
Constitutive Equations ◽  
Slip Velocity ◽  
Test Results ◽  
Explicit Finite Element ◽  
Driving Condition ◽  
Driving Conditions

Abstract Tread pattern wear is predicted by using an explicit finite element model (FEM) and compared with the indoor drum test results under a set of actual driving conditions. One pattern is used to determine the wear rate equation, which is composed of slip velocity and tangential stress under a single driving condition. Two other patterns with the same size (225/45ZR17) and profile are used to be simulated and compared with the indoor wear test results under the actual driving conditions. As a study on the rubber wear rate equation, trial wear rates are assumed by several constitutive equations and each trial wear rate is integrated along time to yield the total accumulated wear under a selected single cornering condition. The trial constitutive equations are defined by independently varying each exponent of slip velocity and tangential stress. The integrated results are compared with the indoor test results, and the best matching constitutive equation for wear is selected for the following wear simulation of two other patterns under actual driving conditions. Tens of thousands of driving conditions of a tire are categorized into a small number of simplified conditions by a suggested simplification procedure which considers the driving condition frequency and weighting function. Both of these simplified conditions and the original actual conditions are tested on the indoor drum test machines. The two results can be regarded to be in good agreement if the deviation that exists in the data is mainly due to the difference in the test velocity. Therefore, the simplification procedure is justified. By applying the selected wear rate equation and the simplified driving conditions to the explicit FEM simulation, the simulated wear results for the two patterns show good match with the actual indoor wear results.

Economic modeling of touristic services demand in the regions

2019 ◽  
pp. 87-93
Author(s):  
Ivan Blahun ◽  
Halyna Leshchuk ◽  
Mariya Kyfor
Keyword(s):  
Systematic Approach ◽  
Income Elasticity ◽  
Probability Model ◽  
Economic Modeling ◽  
Tourism Demand ◽  
Goods And Services ◽  
Household Incomes ◽  
Tourism Services ◽  
Income Decile

Considering the important role of tourism in the socio-economic development of regions, the need for information and modeling of ways to increase demand for tourism services and tourism development is being updated. The article uses methods of analytical, logical, comparative analysis and systematic approach to study trends in demand for tourist services in Ukraine. Econometric modeling analyzes the demand for tourism services by the level of income and expenditures of the population in 2018. Trends in demand for tourism services in 2018 in terms of income and expenditure of the population with the use of the Tornquist econometric model have been analyzed. It is proposed to use the decile groups of the population for analyzing income and expenditure by the level of income, total income per capita, the level of household expenditure relative to income, the percentage of tourism expenditure by households, the expenditure on tourism and the elasticity of tourism demand. Average values of the population’s expenditures on tourism were established, which helped to determine the elasticity of effective demand for each decile group. The more than one unit of elasticity of effective tourism demand for each decile group indicated that tourism services for domestic households belong to the group of luxury goods and services. It should be noted that in the following decile income groups of households there is a decrease in elasticity. It means that when income tends to increase indefinitely, elasticity coefficients fall, and this indicates a stabilization of costs of this type. In this case, the percentage of households in each decile group that recorded the costs of organized tourism in their budgets and the value of the probability of household participation in this form of recreation was determined based on an estimated probability model. An analysis of the values of income elasticity indicators in each income decile group has shown that increasing household incomes contribute to increased demand for tourism services and an increase in the share of expenditures for these purposes in household budgets.

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