Faculty Profile: Bruce Caswell

Bruce Caswell
Bruce Caswell
Professor
Engineering
Work: +1 401-863-1448
Professor Caswell's main area of research is the numerical simulation of flow processes. Current work is directed toward the fluid mechanics of non-Newtonian and viscoelastic liquids, and their analysis by finite element methods. Mechanically these fluids are described by nonlinear constitutive equations of the differential and integral type. The parameters (modulus, viscosity, relaxation times) which appear in these equations must be fitted from rheological data, which, in practice, is incomplete.

Research Description

Professor Caswell's main area of research is the numerical simulation of flow processes. Current work is directed toward the fluid mechanics of non-Newtonian and viscoelastic liquids, and their analysis by finite element methods. Mechanically these fluids are described by nonlinear constitutive equations of the differential and integral type. The parameters (modulus, viscosity, relaxation times) which appear in these equations must be fitted from rheological data, which, in practice, is incomplete. A current project is directed at developing algorithms for optimal fitting with incomplete data. Modern manufacturing techniques are motivated by the need to rapidly produce prototypes of new products. One method of Rapid Prototyping is controlled deposition of micro droplets, which solidify to produce a three-dimensional object layer-upon-layer. Current technology limits the droplet materials to thermoplastic waxes and certain plastics; the goal is to extend the technology to functional materials, especially metals. The simulation problem to be solved is the detailed description of droplet impact on a surface followed by solidification. This work is being carried out in conjunction with experimental work at Cornell University. Molten glass processing is modeled by treating the glass as a Newtonian fluid with a strongly temperature-sensitive viscosity. Hence heat transfer, including relative transfer, is the controlling factor in the simulation of the processing of glass in the molten state. For glasses with stratified refractive index the description of radiative transfer is being developed for application to the simulation of drawing of optical fibers.

Selected Publications

  • "Determination of Relaxation Spectra with Instantaneous Viscosity," Proceedings of XIIth International Congress on Rheology, A. Ait-Kadi, J.M. Dealy, D.F. James and M. Williams, Editors, Quebec, p. 261 (1996). (1996)
  • "Similarity of the Relaxation Modulus of Polydisperse Polymers," (with S.J. Paboojian), Makromol. Chem., Macromol. Symp., 68, 69-94 (1993). (1993)
  • "The Finite Element Analysis of the Upper Jet Region of a Fiber Drawing Field of a Temperature-Sensitive Material," (with R.E. Sayles), Int. J. of Heat and Mass Transfer, 27, 57-67 (1984). (1984)
  • "Finite Element Simulation of Viscoelastic Flow," J. Non-Newtonian Fluid Mech. (with M. Viriyayuthakorn), 6, 245-267 (1980). (1980)