Peter C. Sukanek

Bio: Peter C. Sukanek is an academic researcher from University of Massachusetts Amherst. The author has contributed to research in topics: Couette flow & Taylor–Couette flow. The author has an hindex of 3, co-authored 4 publications receiving 104 citations.

The stability of plane Couette flow with viscous heating

Abstract: An investigation of the stability of plane Couette flow with viscous heating of a Navier–Stokes–Pourier fluid with an exponential dependence of viscosity upon temperature is presented. Using classical small perturbation theory, the stability of the flow can be described by a sixth-order set of coupled ordinary differential equations. Using Galerkin's method, these equations are reduced to an algebraic eigenvalue problem. An eigenvalue with a negative real part means that the flow is unstable.Neutral stability curves are determined at Brinkman numbers of 15, 19, 25, 30,40,80 and 600 for Prandtl numbers of 1, s and 50. A Brinkman number of 19 corresponds approximately to the maximum shear stress which can be applied to the system.The results indicate that four different modes of instability occur: one termed an inviscid mode, arising from an inflexion point in the primary flow; a viscous mode, due to the stratification of viscosity in the flow field and an associated diffusive mechanism; a coupling mode, resulting from the convective and viscous dissipation terms in the energy equation; and finally a purely thermal mode.

An experimental investigation of viscous heating in some simple shear flows

Abstract: Theoretical investigations of viscous heating in the flow of fluids with an exponential dependence of viscosity on temperature have shown that, for a given shear stress, two shear rates are possible. Above a critical value, the stress decreases as the shear rate increases. The present work is an experimental study of this phenomenon in plane and circular Couette flows and in cylindrical Poiseuille flow. ArochlorR 1260, a high viscosity Newtonian fluid with an extremely sensitive viscosity-temperature dependence is used as the test fluid. The results clearly show that two shear rates for Couette flow exist for one measured wall shear stress. Because of the viscosity-pressure dependence of the fluid, the Poiseuille flow results are inconclusive.

The stability of poiseuille flow. An analysis of two- and three-dimensional disturbances

Abstract: Cylindrical Poiseuille Flow is analyzed for its stability to axisymmetric and non-axisymmetric infinitesimal disturbances The perturbation equations defining each case are solved using Galerkin's method The flow is shown to be stable for α Re up to 750 for all cases studied The first azimuthal model (n=1) is the least stable

Instabilities in viscoelastic flows

Abstract: Viscoelastic instabilities are of practical importance, and are the subject of growing interest. Reviewed here are the fresh developments as well as earlier work in this area, organized into the following categories: instabilities in Taylor-Couette flows, instabilities in cone-and-plate and plate-and-plate flows, instabilities in parallel shear flows, extrudate distortions and fracture, instabilities in shear flows with interfaces, instabilities in extensional flows, instabilities in multidimensional flows, and thermohydrodynamic instabilities. Emphasized in the review are comparisons between theory and experiment and suggested directions for future work.

Viscous Dissipation in Shear Flows of Molten Polymers

Abstract: Publisher Summary Heat transfer in flowing molten polymers is largely influenced by rheology–– the rheological properties of the polymer and by the flow geometry. The rheology of steady shear flow can treat most of the heat transfer problems completely. This chapter discusses the heat transfer problem, and classifies the heat transfer and viscous dissipation in molten polymers. The heat transfer in shear flow is analyzed and a large emphasis is laid on replacing the commonly used idealized boundary conditions–– constant wall temperature or constant wall heat flux by more general conditions. The heat transfer at the wall is described by an outer temperature difference and the Biot number that is used successfully for describing the boundary conditions for temperature calculations in solids. The Biot number is appropriate for describing the boundary conditions between isothermal and adiabatical, as they occur in real processes. A unifying concept is developed that makes it possible to comprise the most important shear flow cases into a single one that can be solved with one numerical program. The nonviscometric flow in channels and flow with free boundaries is also discussed. An example of heat transfer in unsteady unidirectional shear flow is also provided.