Full numerical simulations of multifluid flows
dc.contributor.author | Tryggvason, Grétar | en_US |
dc.contributor.author | Ozen Unverdi, S. | en_US |
dc.date.accessioned | 2010-05-06T21:14:00Z | |
dc.date.available | 2010-05-06T21:14:00Z | |
dc.date.issued | 1991-05 | en_US |
dc.identifier.citation | Tryggvason, Grétar; Ozen Unverdi, S. (1991). "Full numerical simulations of multifluid flows." Physics of Fluids A: Fluid Dynamics 3(5): 1455-1455. <http://hdl.handle.net/2027.42/69841> | en_US |
dc.identifier.uri | https://hdl.handle.net/2027.42/69841 | |
dc.description.abstract | To fully understand the behavior of multifluid systems, one must have good insight into the basic micromechanisms that govern the evolution of a single ‘‘structure’’ (e.g., a bubble or a drop) and the interactions of a few such basic entities. In addition to the usual questions about the relative magnitude of the various physical effects (inertia, viscosity, and surface tension) for multifluid systems, the effects of surface phenomena such as contaminants must be addressed. Full numerical simulations are, in principle, ideally suited to provide this information. Not only are all the quantitative data readily available, but various physical processes can be turned on and off at will. In practice, however, simulations of multifluid problems are one of the difficult areas of computational fluid dynamics. Almost all current studies of multifluid problems make a number of simplifications, such as inviscidness, Stokes flow, two‐dimensionality, or axisymmetry. Although such models capture some of the important behavior, they often put severe constraints on the problems that can be investigated.Many of the fundamental processes in multifluid flow involve fully three‐dimensional flows, where both inertia and viscous effects must be accounted for. To address these effects, we have recently developed a front‐tracking method for multifluid, incompressible flows that appears to be both accurate and robust. The method has been implemented for both two‐ as well as fully three‐dimensional situations. In this paper, we will discuss two problems that we are currently investigating using this numerical method: the Rayleigh–Taylor instability and the motion of bubbles and drops. For fluid mixing induced by unstable stratification, the Rayleigh–Taylor instability where a heavy fluid falls into a lighter underlying fluid, is the prototypical example. Indeed, for such flows its importance is similar to that of the Kelvin–Helmholtz instability for fluid mixing induced by a shear flow. For small density stratification, we show that three‐dimensionality can lead to a large amplitude vortex structure that differs considerably from what two‐dimensional simulations predict. The different vortical configuration leads to more rapid nonlinear growth for the fully three‐dimensional case, even though the linear growth rate is the same. We also show how viscosity stratification modifies the evolution. For the weakly stratified case, where inviscid calculations predict symmetric evolution with respect to the heavy and the light fluid, viscosity stratification leads to considerable asymmetry, with the more viscous fluid forming big round bubbles and the less viscous one being confined to narrow fingers. The effect of density stratification for viscous three‐dimensional motion will also be discussed. For many mixing problems, the long‐time state consists of a dispersed phase that forms drops or bubbles in another phase. We will discuss preliminary investigations of such flows. Calculations of rising bubbles for various values of surface tension and viscosity (both in two and three dimensions) appear to correlate well with experimental observations and steady‐state calculations in the literature. The interactions of bubbles with each other, density interfaces, and vortices will also be discussed. | en_US |
dc.format.extent | 3102 bytes | |
dc.format.extent | 107848 bytes | |
dc.format.mimetype | text/plain | |
dc.format.mimetype | application/pdf | |
dc.publisher | The American Institute of Physics | en_US |
dc.rights | © The American Institute of Physics | en_US |
dc.title | Full numerical simulations of multifluid flows | en_US |
dc.type | Article | en_US |
dc.subject.hlbsecondlevel | Physics | en_US |
dc.subject.hlbtoplevel | Science | en_US |
dc.description.peerreviewed | Peer Reviewed | en_US |
dc.contributor.affiliationum | Department of Mechanical Engineering and Applied Mechanics, The University of Michigan, Ann Arbor, Michigan 48109‐1120 | en_US |
dc.description.bitstreamurl | http://deepblue.lib.umich.edu/bitstream/2027.42/69841/2/PFADEB-3-5-1455-1.pdf | |
dc.identifier.doi | 10.1063/1.858042 | en_US |
dc.identifier.source | Physics of Fluids A: Fluid Dynamics | en_US |
dc.owningcollname | Physics, Department of |
Files in this item
Remediation of Harmful Language
The University of Michigan Library aims to describe library materials in a way that respects the people and communities who create, use, and are represented in our collections. Report harmful or offensive language in catalog records, finding aids, or elsewhere in our collections anonymously through our metadata feedback form. More information at Remediation of Harmful Language.
Accessibility
If you are unable to use this file in its current format, please select the Contact Us link and we can modify it to make it more accessible to you.