Runyuan Bai, Research Associate
Hyung Gwon Choi, Research Associate
Antonio Fortes, Aerospace Engineering and Mechanics Department, University of Minnesota, Minneapolis, Minnesota
Roland Glowinski, Mathematics Department, University of Houston, Houston, Texas
Timothy J. Hall, Graduate Student Researcher
Todd Hesla, Graduate Student Researcher
Howard H. Hu, Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania
Ya Dong (Adam) Huang, Research Associate
Yijian (Peter) Huang, Research Associate
Kanchan M. Kelkar, Innovative Research Inc., Minneapolis, Minnesota
Matthew Knepley, Department of Computer Science, Purdue University, West Lafayette, Indiana
Taehwan Ko, Graduate Student Researcher
Thomas S. Lundgren, Faculty Collaborator
Clara Mata, Graduate Student Researcher
Ruslan S. Mudryy, Graduate Student Researcher
Douglas Ocando, Graduate Student Researcher
Tsorng-Whay Pan, Mathematics Department, University of Houston, Houston, Texas
Neelesh Ashok Patankar, Research Associate
Suhas V. Patankar, Faculty Collaborator
Vivek Sarin, Department of Computer Science, Purdue University, West Lafayette, Indiana
Pushpendra Singh, Department of Mechanical Engineering, New Jersey Institute of Technology, Newark, New Jersey
Mingyu Zhu, Graduate Student Researcher
These researchers are continuing work on developing scalable, highly efficient parallel finite-element codes, called particle movers, for the direct numerical simulation of the motion of thousands of solid particles in Newtonian and viscoelastic fluids, in both two and three dimensions.
Two separate particle movers have already been developed. One (the ALE particle mover) is based on a generalization of standard Galerkin finite-element method; it uses an unstructured body-fitted mesh and an ALE scheme to handle the time-dependent domain of the fluid flow. A new mesh is generated when the old one becomes too distorted, and the flow field is projected onto the new mesh. The other (the DLM particle mover) is based on a fictitious-domain method, in which the fluid is imagined to fill the space inside the particle boundaries, and the rigid-body motion inside the particles is enforced via distributed Lagrange multipliers. The DLM particle mover used a fixed, regular mesh over the entire fluid-particle domain. This allows the use of fast solvers, thus enabling quick and efficient computations. Both schemes are based on a combined fluid-particle weak formulation from which the hydrodynamic forces and torques have been eliminated. Both particle movers have been parallelized using domain decomposition and MPI.
Presently, these researchers are continuing their efforts to improve the performance of the particle movers by tailoring the partitioning scheme to produce a division favorable to the multi-level preconditioner being used. They are also experimenting with a new narrow-band preconditioner based on a Schur complement formulation, which could greatly increase the efficiency of the iterative solver. A matrix-free version of the ALE particle mover has also been developed based on an operator splitting method, which will allow much larger problems to be solved. This code is currently being parallelized. In addition, a modified version of the DLM particle mover, which is more easily generalizable to three dimensions, is being developed. The two-dimensional version of this code is already complete, and the three-dimensional version is under development.
99/89 |
"Steady Flow and Interfacial Shapes of a Highly Viscous Dispersed Phase," R. Bai and D.D. Joseph, University of Minnesota Supercomputing Institute Research Report UMSI 99/89, April 1999. Publication in press. |
99/97 |
"Flow Induced Microstructure in Newtonian and Visoelastic Fluids," D.D. Joseph, University of Minnesota Supercomputing Institute Research Report UMSI 99/97, May 1999. |
99/98 |
"A New Formulation of the Distributed Lagrange Multiplier/Fictitious Domain Method for Particulate Flows," N.A. Patankar, P. Singh, D.D. Joseph, R. Glowinski, and T.-W. Pan, University of Minnesota Supercomputing Institute Research Report UMSI 99/98, May 1999. Publication in press. |
99/100 |
"Effects of Shear Thinning on Migration of Neutrally Buoyant Particles in Pressure Driven Flow on Newtonian and Viscoelastic Fluids," P.Y. Huang and D.D. Joseph, University of Minnesota Supercomputing Institute Research Report UMSI 99/100, May 1999. Publication in press. |
99/157 |
"Foamy Oil Flow in Porous Media," D.D. Joseph, A.M. Kamp, R. Bai, and M. Huerta, University of Minnesota Supercomputing Institute Research Report UMSI 99/157, September 1999. |
99/158 |
"Modeling Rayleigh-Taylor Instability of a Sedimenting Suspension Arising in Direct Numerical Simulation," R. Glowinski, T.-W. Pan, and D.D. Joseph, University of Minnesota Supercomputing Institute Research Report UMSI 99/158, September 1999. |
Benchmark tests are being run to compare and cross-validate the various versions of the ALE and DLM particle movers. Several benchmark tests are also being run, in which direct comparisons between computed results and results of actual experiments can be made using the exact same setup. In addition, benchmark tests are being done to test the parallel versions of the codes for speedup and reliability. These researchers are continuing to use their particle movers to study the fundamental dynamics of fluid-particle motions. At present, many-particle resuspension is being simulated in order to develop models of the lift-off of particles from solid surfaces in Newtonian and viscoelastic fluids that can be used in making practical decisions in a variety of engineering applications, including sand transport in fractured oil reservoirs.
|
|
URL: http://www.msi.umn.edu/about/publications/annualreport/ar2000/depts/IT/Aerospace/joseph.html |
|
| This page last modified on Friday, 30-May-2008 16:14:03 CDT | ||
| Please direct questions or problems to help@msi.umn.edu | ||
|
Website related questions or problems should be directed to
webmaster@msi.umn.edu
The Supercomputing Institute does not collect personal information on visitors to our website. For the University of Minnesota policy, see www.privacy.umn.edu. © 2001 by the Regents of the University of Minnesota |
||