Influence of temperature dependent physical properties on liquid metal droplet impact dynamics

2021 ◽  
pp. 1-15
Author(s):  
Akash Chowdhury ◽  
Anandaroop Bhattacharya ◽  
Partha Bandyopadhyay
Keyword(s):  
Surface Tension ◽  
Numerical Solutions ◽  
Substrate Surface ◽  
Metal Droplet ◽  
Navier Stokes ◽  
Complex Flow ◽  
Liquid Metal Droplet ◽  
Aluminium Copper ◽  
Energy Equations ◽  
Surface Tension Forces

Abstract The dynamics of a metal droplet impacting on a substrate surface has been studied in the paper numerically. Numerical solutions of the Navier-Stokes and Energy equations show the evolution of the droplet as it spreads upon impact with the substrate while simultaneously undergoing solidification. The interplay of the different forces including inertia, viscous and surface tension, coupled with solidification of the molten material in layers lead to complex flow dynamics. The change in density and viscosity owing to change in temperature resulting from the cooling process, is found to influence the spreading of the droplet significantly. The model was exercised for three different materials viz. aluminium, copper and nickel to determine the final splat radius as well as spreading time. The surface tension forces as well as solidification rates were found to be the dominant factors in determining the above parameters as well as the shape of the splat during spreading. The results were found to be in good agreement with existing analytical model.

Numerical Solutions of Transients in Pneumatic Networks—Transmission-Line Calculations

1968 ◽  
Vol 35 (3) ◽  
pp. 588-595 ◽  
Author(s):  
S. Tsao
Keyword(s):  
Wave Propagation ◽  
Transmission Lines ◽  
Numerical Solutions ◽  
Navier Stokes ◽  
Damping Factor ◽  
Temperature Profiles ◽  
Hypothetical Case ◽  
One Dimensional ◽  
Simplifying Assumptions ◽  
Energy Equations

Equations governing the damped wave propagation along transmission lines are obtained from the Navier-Stokes and energy equations by making certain simplifying assumptions. The flow considered is essentially one-dimensional. However, radial variations of the velocity and temperature profiles must be considered, because the damping factor is directly dependent on them. The equations are integrated by numerical methods. A hypothetical case is computed as an example.

scholarly journals Calculation of evaporation length of a liquid bridge flowing between inclined hot tubes

2021 ◽  
Vol 2119 (1) ◽  
pp. 012056
Author(s):  
P I Geshev
Keyword(s):  
Nonlinear Integral Equation ◽  
Boundary Integral Equations ◽  
Boundary Integral ◽  
Temperature Fields ◽  
Navier Stokes ◽  
Method Of Boundary Elements ◽  
Hydrostatic Equation ◽  
Velocity And Temperature Fields ◽  
Energy Equations ◽  
Surface Tension Forces

Abstract The bridge consists of liquid held by surface tension forces between two inclined tubes in an LNG heat exchanger. The shape of the bridge is calculated by the hydrostatic equation, which is reduced to a nonlinear integral equation and resolved by the Newton method. The velocity and temperature fields in the bridge are described by the Navier-Stokes and energy equations, respectively. They are reduced to the boundary integral equations and calculated by the method of boundary elements. Heat transfer coefficient is calculated for evaporating bridge and the length of total bridge evaporation is estimated.

Flow Characteristics in a Three-Dimensional Rectangular Channel With a Pair of Ribs Placed Symmetrically at the Channel Walls

2000 ◽  
Author(s):  
M. Singh ◽  
P. K. Panigrahi ◽  
G. Biswas
Keyword(s):  
Heat Transfer ◽  
Large Scale ◽  
Numerical Study ◽  
Rectangular Channel ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Navier Stokes ◽  
Complex Flow ◽  
Energy Equations

Abstract A numerical study of rib augmented cooling of turbine blades is reported in this paper. The time-dependent velocity field around a pair of symmetrically placed ribs on the walls of a three-dimensional rectangular channel was studied by use of a modified version of Marker-And-Cell algorithm to solve the unsteady incompressible Navier-Stokes and energy equations. The flow structures are presented with the help of instantaneous velocity vector and vorticity fields, FFT and time averaged and rms values of components of velocity. The spanwise averaged Nusselt number is found to increase at the locations of reattachment. The numerical results are compared with available numerical and experimental results. The presence of ribs leads to complex flow fields with regions of flow separation before and after the ribs. Each interruption in the flow field due to the surface mounted rib enables the velocity distribution to be more homogeneous and a new boundary layer starts developing downstream of the rib. The heat transfer is primarily enhanced due to the decrease in the thermal resistance owing to the thinner boundary layers on the interrupted surfaces. Another reason for heat transfer enhancement can be attributed to the mixing induced by large-scale structures present downstream of the separation point.

Cavitation Bubble Collapse in Viscous, Compressible Liquids—Numerical Analysis

1965 ◽  
Vol 87 (4) ◽  
pp. 977-985 ◽  
Author(s):  
R. D. Ivany ◽  
F. G. Hammitt
Keyword(s):  
Surface Tension ◽  
High Pressures ◽  
Numerical Solutions ◽  
Compressible Liquid ◽  
Navier Stokes ◽  
Bubble Collapse ◽  
Navier Stokes Equation ◽  
Scaling Parameters ◽  
Collapse Behavior ◽  
Normalized Solution

Collapse of a spherical bubble in a compressible liquid, including the effects of surface tension, viscosity, and an adiabatic compression of gas within the bubble is investigated by numerical solutions of the hydrodynamic equations. A limiting value of shear viscosity causes the bubble collapse to slow down markedly, for both compressible and incompressible liquids, whereas moderate viscosities have very little effect on the rate of collapse. The inclusion of surface tension and viscosity introduces two scaling parameters into the solution, so that a single normalized solution is no longer sufficient to describe collapse behavior. The magnitude of the density changes calculated for the compressible liquid and the extremely rapid changes with time suggest that the usual Navier-Stokes equation of motion may not be appropriate. The possibility of liquid relaxational phenomenon and its contribution to sonoluminescence is considered. Shock waves or damagingly high pressures are not generated during collapse at a distance in the liquid equal to the initial radius from the center of collapse, although they will appear at such a distance if the bubble rebounds.

A Theory of Rotating Condensation

1959 ◽  
Vol 81 (2) ◽  
pp. 113-119 ◽  
Author(s):  
E. M. Sparrow ◽  
J. L. Gregg
Keyword(s):  
Numerical Solutions ◽  
Saturated Vapor ◽  
Large Body ◽  
Rotating Disk ◽  
Disk Surface ◽  
Film Condensation ◽  
Navier Stokes ◽  
Torque Moment ◽  
Prandtl Numbers ◽  
Energy Equations

An analysis is made for film condensation on a rotating disk situated in a large body of pure saturated vapor. The centrifugal field associated with the rotation sweeps the condensate outward along the disk surface, and gravity forces need not be involved. The problem is formulated as an exact solution of the complete Navier-Stokes and energy equations. Numerical solutions are obtained for Prandtl numbers between 0.003 and 100 and for cpΔT/hfg in the range 0.0001 to 1.0. Results are given for the heat transfer, as well as for the condensate layer thickness, torque moment, and temperature and velocity profiles.

The contraction of liquid filaments

1996 ◽  
Vol 309 ◽  
pp. 277-300 ◽  
Author(s):  
R. M. S. M. Schulkes
Keyword(s):  
Surface Tension ◽  
Stokes Equations ◽  
Stability Limit ◽  
Approximate Solutions ◽  
Navier Stokes ◽  
Ohnesorge Number ◽  
Navier Stokes Equations ◽  
Element Discretization ◽  
Surface Tension Forces ◽  
Liquid Filament

In this paper the evolution of a free liquid filament of arbitrary viscosity, contracting under the action of surface tension forces, is studied by numerical means. A finite- element discretization procedure is used to obtain approximate solutions to the Navier-Stokes equations. A Lagrangian approach is employed to deal with the large domain deformations which occur during the evolution of the filament. Typically we find that during the contraction a bulbous region forms at the end of the filament. The character of the evolution of the filament is found to be crucially dependent on the value of the Ohnesorge number Oh (a measure of viscous and surface tension forces). For large Ohnesorge numbers (Oh [Gt ] O(1)) it is found that the liquid filament remains stable during contraction, even when the initial length of the filament is much longer than the Rayleigh stability limit. The bulbous end becomes more localized with decreasing Ohnesorge number while at the same time a clear neck forms in front of the bulbous end. In addition we find that the region in which the pressure is minimum moves towards the neck. For sufficiently small Ohnesorge numbers (Oh [Lt ] O(0.01)) the filament becomes unstable with the radius of the neck decreasing and, eventually, the bulbous end breaking away from the filament.

Measurement of the Surface Tension of Liquid Metal-Droplet in Arc Welding

2013 ◽  
Vol 652-654 ◽  
pp. 2265-2269
Author(s):  
Li Sun ◽  
Xi Bao Wang ◽  
Xiang Liang Li ◽  
Chen Xi Liu
Keyword(s):  
Surface Tension ◽  
Liquid Metal ◽  
Aerodynamic Drag ◽  
Welding Process ◽  
Metal Droplet ◽  
Test Method ◽  
Liquid Metal Droplet ◽  
Welding Arc ◽  
Measurement Results ◽  
Novel Method

The surface tension of the liquid metal droplet was measured in the welding arc fields using a novel method. This method eliminates the interference of the electrode magnetic force and aerodynamic drag force with the measurement results during the welding process. The validity of test method was recognized by both theories and experiments. The surface tensions of the H08A wire melting droplet were measured at various currents.

All Speed and High-Resolution Scheme Applied to Three-Dimensional Multi-Block Complex Flowfield System

2004 ◽  
Vol 20 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Uzu- Kuei Hsu ◽  
Chang- Hsien Tai ◽  
Chien- Hsiung Tsai
Keyword(s):  
Steady State ◽  
Incompressible Flows ◽  
Numerical Solutions ◽  
Stokes Equations ◽  
Diffusion Flux ◽  
Time Derivative ◽  
Splitting Method ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Complex Flow

ABSTRACTThe improved numerical approach is implemented with preconditioned Navier-Stokes solver on arbitrary three-dimensional (3-D) structured multi-block complex flowfield. With the successful application of time-derivative preconditioning, present hybrid finite volume solver is performed to obtain the steady state solutions in compressible and incompressible flows. This solver which combined the adjective upwind splitting method (AUSM) family of low-diffusion flux-splitting scheme with an optimally smoothing multistage scheme and the time-derivative preconditioning is used to solve both the compressible and incompressible Euler and Navier-Stokes equations. In addition, a smoothing procedure is used to provide a mechanism for controlling the numerical implementation to avoid the instability at stagnation and sonic region. The effects of preconditioning on accuracy and convergence to the steady state of the numerical solutions are presented. There are two validation cases and three complex cases simulated as shown in this study. The numerical results obtained for inviscid and viscous two-dimensional flows over a NACA0012 airfoil at free stream Mach number ranging from 0.1 to 1.0E-7 indicates that efficient computations of flows with very low Mach numbers are now possible, without losing accuracy. And it is effectively to simulate 3-D complex flow phenomenon from compressible flow to incompressible by using the advanced numerical methods.

Finite Element Simulations of Gas-Liquid Flows With Surface Tension

2000 ◽  
Author(s):  
Gang Wang
Keyword(s):  
Surface Tension ◽  
Finite Element ◽  
Marangoni Convection ◽  
Surface Force ◽  
Rigid Wall ◽  
Navier Stokes ◽  
Finite Element Program ◽  
Element Program ◽  
Energy Equations ◽  
Liquid Flows

Abstract The finite-element program, ANSYS/FLOTRAN, has been enhanced at Release 5.7 to predict gas-liquid flows with surface tension. The two-dimensional incompressible Navier-Stokes and energy equations are solved in both Cartesian and axisymmetric geometry. The location of the interface is computed and tracked with the CLEAR-VOF algorithm. Normal and tangential boundary conditions at the interface are enforced through a continuum surface force (CSF) model. This new algorithm is first validated with two model problems: a droplet in equilibrium and an oscillating droplet. For the first problem, the computed pressure value is compared with the theoretical value, whereas for the second problem, the oscillation frequency is compared with both the analytical solution and the experimental data. The computer program is then applied to a number of interesting free surface problems: droplet impacting on a rigid wall, binary droplet collision, flow induced by wall adhesion, and marangoni convection in a rectangular cavity.

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