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.

Finite Element Simulations of Free Surface Flows With Surface Tension in Complex Geometries

2002 ◽  
Vol 124 (3) ◽  
pp. 584-594 ◽  
Author(s):  
Gang Wang
Keyword(s):  
Surface Tension ◽  
Finite Element ◽  
Free Surface ◽  
Surface Force ◽  
Free Surface Flows ◽  
Complex Geometries ◽  
Finite Element Program ◽  
Surface Flows ◽  
Static Contact ◽  
Element Program

The finite-element program, ANSYS/FLOTRAN, has been enhanced at Release 5.7 to predict free surface flows with surface tension in complex geometries. The two-dimensional incompressible Navier-Stokes and energy equations are solved in both Cartesian and axisymmetric coordinate systems. At Release 5.6, the free surface capabilities have been incorporated into ANSYS/FLOTRAN using the CLEAR-VOF algorithm. The main contribution of this work is to implement a surface tension model into ANSYS/FLOTRAN to study free surface flows with surface tension in complex geometries. Both normal and tangential components of surface tension forces are modeled at the interface 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 experimental data. The computer program is then applied to thermocapillary flows in two types of trapezoidal cavities to investigate the interesting flow and heat transfer characteristics. Systematic calculations are performed to study the influence of Marangoni number, capillary number and static contact angle on Marangoni convection.

The solution of viscous incompressible jet and free-surface flows using finite-element methods

1974 ◽  
Vol 65 (1) ◽  
pp. 189-206 ◽  
Author(s):  
R. E. Nickell ◽  
R. I. Tanner ◽  
B. Caswell
Keyword(s):  
Surface Tension ◽  
Finite Element ◽  
Free Surface ◽  
Transient Flow ◽  
Reynolds Numbers ◽  
Free Surface Flows ◽  
Stick Slip ◽  
Finite Element Program ◽  
Viscous Forces ◽  
Element Program

We discuss the creation of a finite-element program suitable for solving incompressible, viscous free-surface problems in steady axisymmetric or plane flows. For convenience in extending program capability to non-Newtonian flow, non-zero Reynolds numbers, and transient flow, a Galerkin formulation of the governing equations is chosen, rather than an extremum principle. The resulting program is used to solve the Newtonian die-swell problem for creeping jets free of surface tension constraints. We conclude that a Newtonian jet expands about 13%, in substantial agreement with experiments made with both small finite Reynolds numbers and small ratios of surface tension to viscous forces. The solutions to the related ‘stick-slip’ problem and the tube inlet problem, both of which also contain stress singularities, are also given.

scholarly journals The impact of drilling and slitting construction on damage field: evolution characteristics in low-permeability coal seam

2021 ◽  
Vol 37 ◽  
pp. 205-215
Author(s):  
Heng Chen ◽  
Hongmei Cheng ◽  
Aibin Xu ◽  
Yi Xue ◽  
Weihong Peng
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Damage Mechanics ◽  
Effective Strain ◽  
Secondary Development ◽  
Distribution Area ◽  
Finite Element Program ◽  
Element Program ◽  
Mining Face ◽  
The Impact

ABSTRACT The fracture field of coal and rock mass is the main channel for gas migration and accumulation. Exploring the evolution law of fracture field of coal and rock mass under the condition of drilling and slitting construction has important theoretical significance for guiding efficient gas drainage. The generation and evolution process of coal and rock fissures is also the development and accumulation process of its damage. Therefore, based on damage mechanics and finite element theory, the mathematical model is established. The damage variable of coal mass is defined by effective strain, the elastoplastic damage constitutive equation is established and the secondary development of finite element program is completed by FORTRAN language. Using this program, the numerical simulation of drilling and slitting construction of the 15-14120 mining face of Pingdingshan No. 8 Mine is carried out, and the effects of different single borehole diameters, different kerf widths and different kerf heights on the distribution area of surrounding coal fracture field and the degree of damage are studied quantitatively. These provide a theoretical basis for the reasonable determination of the slitting and drilling arrangement parameters at the engineering site.

Finite Element Analysis on the Deformation of Energy-Saving Wire-Mesh Frame Wallboard

2014 ◽  
Vol 501-504 ◽  
pp. 731-735
Author(s):  
Li Zhang ◽  
Kang Li
Keyword(s):  
Finite Element ◽  
Energy Saving ◽  
Theoretical Basis ◽  
Steel Wire ◽  
Wire Mesh ◽  
Design Parameters ◽  
Element Analysis ◽  
Finite Element Program ◽  
Element Program ◽  
Influence Degree

This paper analyzes the influence degree of related design parameters of wire-mesh frame wallboard on deformation through finite element program, providing theoretical basis for the design and test of steel wire rack energy-saving wallboard.

scholarly journals Numerical Analyses of Earthquake Induced Liquefaction and Deformation Behaviour of an Upstream Tailings Dam

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Auchar Zardari ◽  
Hans Mattsson ◽  
Sven Knutsson ◽  
Muhammad Shehzad Khalid ◽  
Maria V. S. Ask ◽  
...  
Keyword(s):  
Finite Element ◽  
Seismic Event ◽  
Deformation Behaviour ◽  
Ground Surface ◽  
Tailings Dam ◽  
Limited Extent ◽  
Northern Sweden ◽  
Finite Element Program ◽  
Dynamic Analyses ◽  
Element Program

Much of the seismic activity of northern Sweden consists of micro-earthquakes occurring near postglacial faults. However, larger magnitude earthquakes do occur in Sweden, and earthquake statistics indicate that a magnitude 5 event is likely to occur once every century. This paper presents dynamic analyses of the effects of larger earthquakes on an upstream tailings dam at the Aitik copper mine in northern Sweden. The analyses were performed to evaluate the potential for liquefaction and to assess stability of the dam under two specific earthquakes: a commonly occurring magnitude 3.6 event and a more extreme earthquake of magnitude 5.8. The dynamic analyses were carried out with the finite element program PLAXIS using a recently implemented constitutive model called UBCSAND. The results indicate that the magnitude 5.8 earthquake would likely induce liquefaction in a limited zone located below the ground surface near the embankment dikes. It is interpreted that stability of the dam may not be affected due to the limited extent of the liquefied zone. Both types of earthquakes are predicted to induce tolerable magnitudes of displacements. The results of the postseismic slope stability analysis, performed for a state after a seismic event, suggest that the dam is stable during both the earthquakes.

A preprocessor for the finite element program SAP IV

1981 ◽  
Vol 17 (12) ◽  
pp. 1779-1789
Author(s):  
E. Haugeneder ◽  
W. Prochazka ◽  
P. Tavolato
Keyword(s):  
Finite Element ◽  
Finite Element Program ◽  
Element Program

Abstract 2871: Saddle-Shaped Annuloplasty Reduces Mitral Leaflet Stress: A Real-Time 3D Echocardiographic Study

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Aaron S Blom ◽  
Chun Xu ◽  
Liam P Ryan ◽  
Benjamin Jackson ◽  
Landi M Parish ◽  
...  
Keyword(s):  
Finite Element ◽  
Real Time ◽  
Stress Reduction ◽  
Heart Association ◽  
Posterior Leaflet ◽  
Volume Data ◽  
Medical Systems ◽  
Annuloplasty Ring ◽  
Finite Element Program ◽  
Element Program

Objectives: High leaflet and chordal stresses contribute to recurrent mitral regurgitation after repair procedures. We hypothesized that a saddle-shaped annuloplasty ring would reduce leaflet stress compared to a similarly sized flat annuloplasty ring. To test this hypothesis we used a novel 3D echocardiographically-based finite element modeling (FEM) technique for quantifying regional mitral valve stress. Methods: Real-time 3D echocardiography was performed in 8 sheep before and after placement of either a 30mm flat annuloplasty (n=4) or a 30mm saddle-shaped annuloplasty. Full-volume data sets of the MV were obtained using an IE33 platform(Philips Medical Systems, Andover, Massachusetts) and exported to Cardio-View (Tomtec Imaging Systems, Munich, Germany) for image analysis. Individual leaflet data were then interpolated using Matlab (The Mathworks, Natick, Massachusetts). Triangulated leaflet surfaces were extracted and the data imported into a commercial finite element program (ABAQUS/Explicit 6.3, HKS Inc. Pawtucket, RI) to quantify regional stress distributions in all segments (P1, P2, P3 and A1, A2, A3) of the MV. Results: Peak anterior and posterior leaflet stresses after flat annuloplasty placement were 0.20±0.001MPa and 21±0.02MPa. Peak anterior and posterior leaflet stress after saddle-shaped annuloplasty placement was 0.19±0.02MPa and 13±0.01MPa (p<0.05 for the posterior leaflet stresses) Conclusions: Saddle-shaped annuloplasty design results in greater stress reduction in the posterior leaflet than standard flat annuloplasty rings and may, therefore, result in more durable repairs. This research has received full or partial funding support from the American Heart Association, AHA Great Rivers Affiliate (Delaware, Kentucky, Ohio, Pennsylvania & West Virginia).

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