Dual-Species Transport Subject to Sorptive Exchange in Pipe Flow

2003 ◽  
Vol 70 (4) ◽  
pp. 550-560 ◽  
Author(s):  
T. L. Yip ◽  
C. O. Ng
Keyword(s):  
Asymptotic Analysis ◽  
Pipe Flow ◽  
Solid Phase ◽  
Chemical Species ◽  
Transport Equations ◽  
Species Transport ◽  
Numerical Example ◽  
Effective Transport ◽  
Solid Suspension ◽  
Two Phases

The transport in pipe flow of a chemical species can be materially affected by the presence of solid suspension if the species is capable of partitioning into a solute phase and a solid phase sorbed onto the suspended particles. An asymptotic analysis is used in this work to deduce the effective transport equations for the two phases, with kinetic sorptive exchange taken into account. The effects of sorption on the advection and dispersion of a sorbing chemical are discussed and illustrated with a numerical example.

Kinematic and Dynamic Parameters of a Liquid-Solid Pipe Flow Using DPIV∕Accelerometry

2007 ◽  
Vol 129 (11) ◽  
pp. 1415-1421 ◽  
Author(s):  
Joseph Borowsky ◽  
Timothy Wei
Keyword(s):  
Pipe Flow ◽  
Solid Phase ◽  
Fluid Phase ◽  
Central Moment ◽  
Steady Flows ◽  
Dynamic Parameters ◽  
Two Phase ◽  
Turbulence Structures ◽  
Two Phases ◽  
Flat Profile

An experimental investigation of a two-phase pipe flow was undertaken to study kinematic and dynamic parameters of the fluid and solid phases. To accomplish this, a two-color digital particle image velocimetry and accelerometry (DPIV∕DPIA) methodology was used to measure velocity and acceleration fields of the fluid phase and solid phase simultaneously. The simultaneous, two-color DPIV∕DPIA measurements provided information on the changing characteristics of two-phase flow kinematic and dynamic quantities. Analysis of kinematic terms indicated that turbulence was suppressed due to the presence of the solid phase. Dynamic considerations focused on the second and third central moments of temporal acceleration for both phases. For the condition studied, the distribution across the tube of the second central moment of acceleration indicated a higher value for the solid phase than the fluid phase; both phases had increased values near the wall. The third central moment statistic of acceleration showed a variation between the two phases with the fluid phase having an oscillatory-type profile across the tube and the solid phase having a fairly flat profile. The differences in second and third central moment profiles between the two phases are attributed to the inertia of each particle type and its response to turbulence structures. Analysis of acceleration statistics provides another approach to characterize flow fields and gives some insight into the flow structures, even for steady flows.

From Nanocomposite Aerogels to Glass Ceramics for Nuclear Wastes Containment

2011 ◽  
Vol 172-174 ◽  
pp. 791-796 ◽  
Author(s):  
Thierry Woignier ◽  
Jerome Reynes ◽  
Sylvie Calas
Keyword(s):  
Viscous Flow ◽  
Thermal Shock ◽  
Nuclear Waste ◽  
High Resistance ◽  
Solid Phase ◽  
Glass Ceramics ◽  
Chemical Species ◽  
Host Matrix ◽  
Waste Containment ◽  
Two Phases

Nanocomposite aerogel is proposed as a host matrix for the synthesis of glass ceramics. The large porosity is used as a sponge to incorporate chemical species getting a two phases material. We describe the steps of the synthesis of glass ceramics for nuclear waste containment, from nanocomposite aerogels loaded with actinides surrogates (Ce and Nd). The glass synthesis is obtained without melting, by a control of several solid phase transformations: sintering, viscous flow, crystallization and foaming. Thanks to their high resistance to thermal shock and water corrosion, these glass ceramics are certainly good candidates as actinides containment materials.

Development of a Log-Time Integration Method for Reactive Flows

2012 ◽  
Author(s):  
Jose Escobar ◽  
Ismail Celik ◽  
Donald Ferguson
Keyword(s):  
Integration Method ◽  
Time Integration ◽  
Chemical Species ◽  
Transport Equations ◽  
Computational Time ◽  
Species Transport ◽  
One Dimensional ◽  
Time Integration Method ◽  
Runge Kutta Method ◽  
Runge Kutta

In reactive flow simulations integration of the stiff species transport equations consumes most of the computational time. Another important aspect of combustion simulation is the need to simulate at least tens of species in order to accurately predict emissions and the related combustion dynamics. Small time scales and systems with tens of species lead to very high computational costs. Classic integration methods such as Euler method are restricted by the smallest characteristic time scale, and explicit Runge-Kutta methods require intermediate predictor corrector steps which make the problem computationally expensive. On the other hand, implicit methods are also computationally expensive due the calculation of the Jacobian. This work presents a strategy to significantly reduce computational time for integration of species transport equations using a new explicit integration scheme called Log-Time Integration Method (LTIM). LTIM is fairly robust and can compete with methods such as the 5th order Runge-Kutta method. Results showed that LTIM applied to the solution of a zero dimensional reactive system which consists of 4 chemical species obtains the solution around 4 times faster than 5th order Runge-Kutta method. LTIM was also applied to the solution of a one dimensional methane-air flame. The chemical reactions were modeled using a reduced chemical mechanism ARM9 that consists of 9 chemical species and 5 global reactions. The solution was carried out for 9 species transport equations along with the energy equation. Governing equations were decoupled into flow and chemical parts and were solved separately using a split formulation. Thermodynamic properties were obtained using NASA format polynomials and transport properties using kinetic-theory formulation. It is shown that the new one dimensional flame code is able to calculate the adiabatic flame temperature of the system and corresponding flame speed for the methane-air flame thus validating its robustness and accuracy.

Thermodynamical study of (CaGa2S4)x(BaGa2S4)1−x solid solutions

2021 ◽  
pp. 2150469
Author(s):  
T. G. Naghiyev ◽  
R. M. Rzayev
Keyword(s):  
Free Energy ◽  
Solid Solutions ◽  
Calculation Method ◽  
Solid Phase ◽  
Ternary Compounds ◽  
Free Energy Of Formation ◽  
Concentration Dependences ◽  
Solid Phase Reactions ◽  
Two Phases ◽  
Energy Of Formation

The solid solutions of [Formula: see text] were synthesized by solid-phase reactions from powder components of CaS, BaS, and Ga2S3. The temperature-concentration dependences of the Gibbs free energy of formation of [Formula: see text] solid solutions from ternary compounds and phase diagrams of the CaGa2S4–BaGa2S4 were determined by a calculation method. It was revealed that continuous solid solutions are formed in these systems. The spinodal decomposition of [Formula: see text] solid solutions into two phases is predicted at ordinary temperatures.

The Benefits and Limitations of Methods Development in Solid Phase Extraction: Mini Review

2014 ◽  
Vol 69 (4) ◽  
Author(s):  
Norfahana Abd-Talib ◽  
Siti Hamidah Mohd-Setapar ◽  
Aidee Kamal Khamis
Keyword(s):  
Sample Preparation ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Liquid Extraction ◽  
Phase Extraction ◽  
Methods Development ◽  
Liquid Liquid Extraction ◽  
Target Analytes ◽  
Two Phases ◽  
Preparation Techniques

Over recent years, there has been an explosive growth of sample preparation techniques. Sample preparation is in most cases meant to be the isolation online or offline concentration of some components of interest or target analytes. Solid phase extraction (SPE) is a very popular technique nowadays in sample preparation. The principal is quite similar with liquid- liquid extraction (LLE) which involves partition of solutes between two phases. But, there are some differences between them and some benefits and limitations of difference types of SPE technique like presented in this paper.

The Metallurgical Characterization of Iron-Containing Concentrate

2020 ◽  
Vol 989 ◽  
pp. 428-433
Author(s):  
B.M. Myrzaliev ◽  
Kulgamal A. Nogaeva ◽  
E.B. Kolmachikhina
Keyword(s):  
Solid Phase ◽  
Metallic Copper ◽  
Iron Alloys ◽  
Metallic Phase ◽  
Phase Reduction ◽  
Slag Copper ◽  
Metallurgical Characterization ◽  
Two Phases ◽  
Metallization Process

The expediency of processing iron-containing concentrate with low iron content, increased content of manganese and copper is considered in the article. To process such a concentrate, a metallization process is proposed to produce sponge iron with a reducing agent - carbon. It was found that in solid-phase reduction at 1150 °C iron is reduced to a greater extent, as well as small particles with a copper content of about 95%, manganese is not recovered. The simulation process of metallization with carbon at a temperature of 1250 °C shows that iron is mainly distributed in the metallic phase, to a lesser extent in slag phases, manganese is distributed in two phases - metal and slag, copper is presented as a separate phase of metallic copper in the composition with iron alloys, and also composes a part of iron alloys. The reduction degree from concentrate to the metallic part is 80 - 91% for iron and 95 - 98% for copper. The presence of metallized particles of various sizes, representing phases of iron with manganese and copper was found in the slags.

Quantitative Evaluation of the Interfacial Free Energies at A Solid-Liquid Lamellar Eutectic Interface

1981 ◽  
Vol 12 ◽  
Author(s):  
W. F. Kaukler ◽  
J. W. Rutter
Keyword(s):  
Free Energy ◽  
Solid Phase ◽  
Interfacial Free Energy ◽  
Eutectic System ◽  
Liquid Interfaces ◽  
Free Energies ◽  
Two Phases ◽  
Interfacial Free Energies ◽  
The Individual ◽  
Solid Liquid

The solid-liquid interfacial free energies of each of the individual phases comprising the eutectic system, Carbon Tetrabromide-Hexachloroethane, were measured as a function of composition using a “grain boundary groove” technique. Thermodynamic data were combined with groove shape measurements made from high resolution optical photomicrographs of the solid-liquid interfaces to give the interfacial free energy data. An interfacial free energy balance at the eutectic trijunction was performed to obtain all the forces acting on that point. The three interphase interfacial free energies at the eutectic trijunctions as well as a solid-solid phase boundary torque were evaluated.It was found that the solid-liquid interfacial free energies of the two phases of the eutectic could be evaluated from photomicrographs of growing or stationary eutectic interfaces. In addition, it was found that for a substantial range of freezing conditions the eutectic interface shape can be predicted from a knowledge of the interfacial free energies alone.

The cell theory of liquids. III. Fusion

1957 ◽  
Vol 240 (1221) ◽  
pp. 265-273 ◽  
Keyword(s):  
Solid Phase ◽  
Freezing Point ◽  
Force Model ◽  
Condensed Phases ◽  
Correlation Effects ◽  
Harmonic Force ◽  
Theory Of Liquids ◽  
Binary Correlation ◽  
Two Phases ◽  
Solid Argon

Correlation effects in liquids at high densities and solids are investigated. Convergence of the ‘correlation expansion’ of the phase integral is tested for a ‘harmonic force’ model, and found to be very satisfactory. The binary correlation correction for the 12–6 potential at the temperature kT/∊ = 0∙75 is evaluated approximately, and shown to give rise to a concave region in the curve of free energy against volume, indicating the existence of two condensed phases. For this temperature the pressure at which the two phases are in equilibrium is negative, i. e. the solid phase is more stable at zero pressure. An approximate extrapolation indicates that the zero pressure freezing-point is about kT F /∊ = 0∙90, somewhat higher than the value 0∙70 observed for argon. The most likely of several possible explanations of the discrepancy is the effect of non-additive interactions in reducing the cohesion of solid argon. The calculated properties of the liquid are in better agreement with observed values for argon than those calculated neglecting correlations.

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