Numerical study on droplets impacting solid spheres: Effect of fluid properties and sphere diameter

2021 ◽  
pp. 126862
Author(s):  
Yuxuan Du ◽  
Ji Liu ◽  
Yanzhi Li ◽  
Jiayu Du ◽  
Xinxin Wu ◽  
...  
Keyword(s):  
Numerical Study ◽  
Sphere Diameter ◽  
Fluid Properties ◽  
Solid Spheres

Numerical Study of Droplet Evaporation in a High-Temperature Stream

1983 ◽  
Vol 105 (2) ◽  
pp. 389-397 ◽  
Author(s):  
M. Renksizbulut ◽  
M. C. Yuen
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Number Range ◽  
Transfer Rates ◽  
Pressure Drag ◽  
Continuity Equations ◽  
Stream Density ◽  
Solid Spheres

Numerical solutions for high-temperature air flowing past water and methanol droplets and solid spheres, and superheated steam flowing past water droplets were obtained in the Reynolds number range of 10 to 100. The coupled momentum, energy, and specie continuity equations of variable thermophysical properties were solved using finite difference techniques. The numerical results of heat transfer and total drag agree well with existing experimental data. Mass transfer decreases friction drag significantly but at the same time increases pressure drag by almost an equal amount. The net effect is that the standard drag curve for solid spheres can be used for evaporating droplets provided the density is the free stream density and the viscosity of the vapor mixture is evaluated at an appropriate reference temperature and concentration. Both the mass efflux and variable properties decrease heat transfer rates to the droplets.

Numerical Modelling of Droplet Deformation in a High-Pressure Homogeniser

2002 ◽  
Author(s):  
David S. Whyte ◽  
Steven Carnie ◽  
Malcolm Davidson
Keyword(s):  
High Pressure ◽  
Numerical Modelling ◽  
Numerical Study ◽  
Extensional Flow ◽  
Operating Conditions ◽  
Droplet Deformation ◽  
Photographic Paper ◽  
Turbulent Fluctuations ◽  
Fluid Properties ◽  
Break Up

A numerical study of droplet deformation in a high-pressure homogeniser is presented. This work is an attempt to identify flow criteria responsible for droplet break-up in a homogeniser used to produce dispersions for the manufacture of photographic paper. The main goal of this study is to recommend changes to homogeniser flow & geometry, operating conditions or fluid properties that will enhance droplet break-up. Laminar elongation, turbulent stresses within the orifice and downstream turbulence and cavitation have been suggested as possible mechanisms within the homogeniser for droplet rupture. Results for simulations, using a combination of homogeniser and droplet scale computation indicate that droplets are unaffected by local extensional flow or turbulent fluctuations and that other mechanisms must be responsible for droplet break-up.

A Numerical Study of Three-Dimensional Convective Heat Transfer From a Window Covered by a Simple Partially-Open Plane Blind

2008 ◽  
Author(s):  
Patrick H. Oosthuizen ◽  
Murat Basarir ◽  
David Naylor
Keyword(s):  
Heat Transfer ◽  
Numerical Study ◽  
Three Dimensional ◽  
Side Surface ◽  
Governing Equations ◽  
Three Dimensional Flow ◽  
Buoyancy Forces ◽  
Fluid Properties ◽  
Higher Temperature ◽  
Open Plane

Heat transfer from the room-side surface of a window covered by a plane blind to the surrounding room has been considered. The window is at a higher temperature than the air in the room. There is an open gap between the blind system and the window at the top of the window and the effect of the size of this gap on the window-to-air heat transfer rate has been numerically examined. Three-dimensional flow has been considered. The flow has been assumed to be steady and laminar and it has been assumed that the fluid properties are constant except for the density change with temperature which gives rise to the buoyancy forces, this having been treated by using the Boussinesq approach. It has also been assumed that the flow is symmetrical about the vertical centre-plane of the window. The solution has been obtained by numerically solving the full three-dimensional form of the governing equations, these equations being written in terms of dimensionless variables. Results have only been obtained for a Prandtl number of 0.7. The effects of the other dimensionless parameters on the window Nusselt number have been numerically determined.

scholarly journals A Numerical Study of Factors Affecting Fracture-Fluid Cleanup and Produced Gas/Water in Marcellus Shale: Part II

SPE Journal ◽  
2016 ◽  
Vol 22 (02) ◽  
pp. 596-614 ◽  
Author(s):  
Maxian B. Seales ◽  
Robert Dilmore ◽  
Turgay Ertekin ◽  
John Yilin Wang
Keyword(s):  
Multiphase Flow ◽  
Numerical Study ◽  
Marcellus Shale ◽  
Reservoir Rock ◽  
Fracture Treatment ◽  
Well Performance ◽  
Shale Formations ◽  
Fracture Fluid ◽  
Fluid Properties

Summary Horizontal wells combined with successful multistage-hydraulic-fracture treatments are currently the most-established method for effectively stimulating and enabling economic development of gas-bearing organic-rich shale formations. Fracture cleanup in the stimulated reservoir volume (SRV) is critical to stimulation effectiveness and long-term well performance. However, fluid cleanup is often hampered by formation damage, and post-fracture well performance frequently falls to less than expectations. A systematic study of the factors that hinder fracture-fluid cleanup in shale formations can help optimize fracture treatments and better quantify long-term volumes of produced water and gas. Fracture-fluid cleanup is a complex process influenced by multiphase flow through porous media (relative permeability hysteresis, capillary pressure), reservoir-rock and -fluid properties, fracture-fluid properties, proppant placement, fracture-treatment parameters, and subsequent flowback and field operations. Changing SRV and fracture conductivity as production progresses further adds to the complexity of this problem. Numerical simulation is the best and most-practical approach to investigate such a complicated blend of mechanisms, parameters, their interactions, and subsequent effect on fracture-fluid cleanup and well deliverability. In this paper, a 3D, two-phase, dual-porosity model was used to investigate the effect of multiphase flow, proppant crushing, proppant diagenesis, shut-in time, reservoir-rock compaction, gas slippage, and gas desorption on fracture-fluid cleanup and well performance in Marcellus Shale. The research findings have shed light on the factors that substantially constrain efficient fracture-fluid cleanup in gas shales, and we have provided guidelines for improved fracture-treatment designs and water management.

Combined Experimental and Numerical Study of a New Configuration of Multiple Microchannel Heat Sink for Heat Removal

2011 ◽  
Author(s):  
Jingru Zhang ◽  
Yogesh Jaluria
Keyword(s):  
Heat Sink ◽  
Single Phase ◽  
Numerical Study ◽  
Heat Removal ◽  
Device Fabrication ◽  
Experimental Results ◽  
Microchannel Heat Sink ◽  
Commercial Code ◽  
Fluid Properties ◽  
Heat Sink Design

In this paper, single phase incompressible liquid flow in a new microchannel heat sink design, which includes flow bifurcation, is studied experimentally and numerically. The experimental setup and device fabrication are briefly explained. The experimental results are presented with uncertainty in the measurements. The numerical model is based on a commercial code and is validated by experimental results with the same initial and boundary conditions. Numerical results with both constant fluid properties and variable properties are compared with the experimental data. The thermal-hydraulic performance of the new design is investigated. The effects of the resulting fluid flow and the geometry on the thermal resistance of the system are discussed.

Numerical Study of Pipeline-Riser Slugging in an Open Source Way

2016 ◽  
Author(s):  
Xiangyin Meng ◽  
Longbin Tao
Keyword(s):  
Open Source ◽  
Mesh Generation ◽  
Pressure Fluctuation ◽  
Numerical Study ◽  
Internal Flow ◽  
Post Process ◽  
System Pressure ◽  
Fluid Properties ◽  
Gas Liquid Flow ◽  
First Time

This paper describes an open source numerical investigation into slugging flow in a typical two-dimensional pipeline-riser for the first time. CFD tools Gmsh, OpenFOAM and ParaView are employed for mesh generation, numerical simulation and post process respectively. Original OpenFOAM solver ‘twoPhaseEulerFoam’ is used to simulate the gas-liquid flow in the system consisting of inclined pipeline and vertical riser. By comparing the numerical results of slugging phenomena and pressure fluctuation periods to previous experimental observations, it can be confirmed that it is possible to carry out such simulations in a complete open source way. Based on case studies, pressure fluctuation features in a typical single slugging cycle is also discussed in details. Furthermore, temperature variation of the internal flow due to air compressibility is found to have similar fluctuation period as that of pressure. In the end, the impacts of fluid properties on system pressure variations are discussed too. To future numerical investigations of subsea pipeline-riser induced slugging, present work is a basis for further open source solvers development.

Eddie Leonardi Memorial Lecture: “Natural Convection From Earth to Space”

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Victoria Timchenko
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Numerical Solutions ◽  
Numerical Study ◽  
Three Dimensional ◽  
Experimental Investigations ◽  
Memorial Lecture ◽  
Numerical Studies ◽  
Fluid Properties ◽  
Microgravity Conditions

This lecture is dedicated to the memory of Professor Eddie Leonardi, formerly International Heat Transfer Conference (IHTC-13) Secretary, who tragically died at an early age on December 14, 2008. Eddie Leonardi had a large range of research interests: he worked in both computational fluid dynamics/heat transfer and refrigeration and air-conditioning for over 25 years. However starting from his Ph.D. ‘A numerical study of the effects of fluid properties on natural convection’ awarded in 1984, one of his main passions has been natural convection and therefore the focus of this lecture will be on what Eddie Leonardi has achieved in numerical and experimental investigations of laminar natural convective flows. A number of examples will be presented which illustrate important difficulties of numerical calculations and experimental comparisons. Eddie Leonardi demonstrated that variable properties have important effects and significant differences occur when different fluids are used, so that dimensionless formulation is not appropriate when dealing with flows of fluids with significant changes in transport properties. Difficulties in comparing numerical solutions with either numerically generated data or experimental results will be discussed with reference to two-dimensional natural convection and three-dimensional Rayleigh–Bénard convection. For a number of years Eddie Leonardi was involved in a joint US-French-Australian research program—the MEPHISTO experiment on crystal growth—and studied the effects of convection on solidification and melting under microgravity conditions. Some results of this research will be described. Finally, some results of experimental and numerical studies of natural convection for building integrated photovoltaic (BIPV) applications in which Eddie Leonardi had been working in the last few years will be also presented.

Sign in / Sign up

Export Citation Format

Share Document