Two-parameter model of two-phase turbulent nonisothermal flow with particles, burning in the vapor-phase regime

1989 ◽  
Vol 25 (5) ◽  
pp. 576-582
Author(s):  
L. B. Gavin ◽  
S. V. Medvedev
Keyword(s):  
Vapor Phase ◽  
Nonisothermal Flow ◽  
Two Phase ◽  
Two Parameter

scholarly journals Two-Phase and Vapor-Phase Thermophysical Property (pvTz) Measurements of the Difluoromethane + trans-1,3,3,3-Tetrafluoroprop-1-ene Binary System

2020 ◽  
Vol 65 (4) ◽  
pp. 1554-1564 ◽  
Author(s):  
Sebastiano Tomassetti ◽  
Uthpala A. Perera ◽  
Giovanni Di Nicola ◽  
Mariano Pierantozzi ◽  
Yukihiro Higashi ◽  
...  
Keyword(s):  
Binary System ◽  
Thermophysical Property ◽  
Vapor Phase ◽  
Two Phase

Simultaneous two-phase PIV by two-parameter phase discrimination

2002 ◽  
Vol 32 (2) ◽  
pp. 252-268 ◽  
Author(s):  
D. A. Khalitov ◽  
E. K. Longmire
Keyword(s):  
Two Phase ◽  
Phase Discrimination ◽  
Two Parameter

Comparison of Reduced and Conventional Two-Phase Flash Calculations

SPE Journal ◽  
2014 ◽  
Vol 20 (02) ◽  
pp. 294-305 ◽  
Author(s):  
S.E.. E. Gorucu ◽  
R.T.. T. Johns
Keyword(s):  
Variable Number ◽  
Binary Interaction ◽  
Binary Interaction Parameter ◽  
Computational Time ◽  
Compositional Simulation ◽  
Two Phase ◽  
Number Of Components ◽  
Speed Up ◽  
Conventional Methods ◽  
Two Parameter

Summary Phase-equilibrium calculations become computationally intensive in compositional simulation as the number of components and phases increases. Reduced methods were developed to address this problem, where the binary-interaction-parameter (BIP) matrix is approximated either by spectral decomposition (SD), as performed by Hendriks and van Bergen (1992), or with the two-parameter BIP formula of Li and Johns (2006). Several authors have recently stated that the SD method—and by reference all reduced methods—is not as fast as previously reported in the literature. In this paper we present the first study that compares all eight reduced and conventional methods published to date by use of optimized code and compilers. The results show that the SD method and its variants are not as fast as other reduced methods, and can be slower than the conventional approach when fewer than 10 components are used. These conclusions confirm the findings of recently published papers. The reason for the slow speed is the requirement that the code must allow for a variable number of eigenvalues. We show that the reduced method of Li and Johns (2006) and its variants, however, are faster because the number of reduced parameters is fixed to six, which is independent of the number of components. Speed up in flash calculations for their formula is achieved for all fluids studied when more than six components are used. For example, for 10-component fluids, a speed up of 2–3 in the computational time for Newton-Raphson (NR) iterations is obtained compared with the conventional method modeled after minimization of Gibbs energy. The reduced method modeled after the linearized approach of Nichita and Graciaa (2011), which uses the two-parameter BIP formula of Li and Johns (2006), is also demonstrated to have a significantly larger radius of convergence than other reduced and conventional methods for five fluids studied.

Pressure Drop in a Capillary Tube in Boiling Two-Phase Flow

2003 ◽  
Author(s):  
Fumito Kaminaga ◽  
Baduge Sumith ◽  
Kunihito Matsumura
Keyword(s):  
Pressure Drop ◽  
Vapor Phase ◽  
Mass Flux ◽  
Two Phase Flow ◽  
Capillary Tube ◽  
Flow Boiling ◽  
Phase Flow ◽  
Two Phase ◽  
System Pressure ◽  
Phase Pressure

Two-phase pressure drop is experimentally examined in a flow boiling condition in a tube of diameter 1.45 mm using water in ranges of pressure from 10 to 100 kPa, mass flux from 18 to 152 kg/m2s, heat flux from 13 to 646 kW/m2, and exit quality from 0.02 to 0.77. Also, pressure drop in an adiabatic air-water two-phase flow is measured at atmospheric pressure using the same test section and mass flux ranges of liquid and gas as those in the flow boiling. Decreasing system pressure the pressure drop significantly increases at a given mass flux. Influence of vapor phase on the pressure drop is found to be large both in the adiabatic and the diabatic conditions. The frictional pressure drop correlation for the adiabatic two-phase flow is developed and applied to predict pressure drop in the flow boiling. But it cannot give satisfactory predictions. The Chisholm correlation calculating a two-phase pressure drop multiplier is modified to account the influence of vapor phase in a capillary tube and the modified correlation can predict the pressure drop in the flow boiling within an error of 20%.

scholarly journals Studies on the Extraction of Metal Complexes. V. Two-parameter Equations for a Complex-formation System and their Application to the Two-phase Distribution of Metal Complexes.

1953 ◽  
Vol 7 ◽  
pp. 663-676 ◽  
Author(s):  
David Dyrssen ◽  
Lars Gunnar Sillén ◽  
John Rastrup-Andersen ◽  
Jörgine Stene Sörensen ◽  
Nils Andreas Sörensen
Keyword(s):  
Complex Formation ◽  
Metal Complexes ◽  
Phase Distribution ◽  
Two Phase ◽  
Two Parameter ◽  
Formation System

Numerical study on evaporation heat transfer characteristics of water in inclined microchannels with varying inlet vapor quality

2019 ◽  
Vol 16 (1) ◽  
pp. 125-131
Author(s):  
Vivekanand SVB ◽  
Raju VRK
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Vapor Phase ◽  
Heated Wall ◽  
Phase Flow ◽  
Vapor Quality ◽  
Heat Transfer Characteristics ◽  
Two Phase ◽  
Ansys Fluent ◽  
Content Type

PurposeThe purpose of this paper is to investigate the effects of gravity on the heat transfer behavior of the two-phase flow of water undergoing phase change. Most of the earlier studies of convective boiling considered systems where the gravity is neglected. In contrast, the authors investigated systems where the gravity is considered. The heat transfer characteristics of water during its evaporation in microchannel heat sink are studied for different channel inclinations.Design/methodology/approachComputational fluid dynamics software ANSYS Fluent is used for the computational study. The volume of fluids multiphase method available in the package is used to capture the vapor–liquid interface. Heat transfer studies are carried out for a rectangular microchannel having a characteristic dimension of 825 µm at different inclinations, which varied from −90° (vertically downward) to 90° (vertically upward). During each simulation, the vapor quality is set at the inlet. Uniform heat flux of 250 kW/m2is applied at the bottom wall of the channel in all orientations of the channel, keeping the upper wall insulated.FindingsAs compared to horizontal configuration, a significant increase in the values of heat transfer coefficient during the fluid flow in inclined microchannels is noticed. It is observed that the Nusselt number for the vertically upward (+90°) and horizontal (0°) configuration are similar and that for the 45° upward configuration exceeds other configurations. It is also observed that the heat transfer performance becomes lower in downward configurations; nearly 40-50 per cent drop in average Nusselt number is observed for a mass flux of 250 kg m-2s-1with respect to 45° inclined microchannel. This behavior can be attributed to the gravitational effect on the two-phase flow because of which the vapor phase being less dense moves away from the heated wall, whereas the primary phase being heavier moves towards the heated wall of the channel. Also, the conductivity of the liquid being higher than the vapor phase, as well as the aperture of the liquid being small during this process, its velocity increases resulting in the augmentation of heat transfer.Originality/valueUser-defined-functions for the mass and energy source terms have been written in C code and hooked in ANSYS Fluent to incorporate the phase change mechanism during the evaporation of water.

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