No abstract

NOTATION AJAf = amplitude of surface center-line oscillation/amplitude of floor oscillation B = model parameter related to the amount of deformation at which the surface loses its memory (see Gardner, 1975) LITERATURE CITED Addison, Greek Letten model parameter model parameter dirac delta function surface shear rate magnitude steady shear surface shear viscosity complex surface viscosity dynamic surface viscosity (real part of 11') imaginary part of zero shear rate surface viscosity infinite shear rate surface viscosity relaxation time surface pressure = floor rotation rate, maximum allowable rotation rate frequency Applications of a Stretch Model Diffusion, and Reaction in Laminar and Turbulent FlowsIn a Lagrangian frame of reference based on lamina (fluid filament) thickness and in a warped time scale based on a single, flow dependent quantity, mixing, diffusion, and reaction can be described in a relatively simple way. Applications are presented for stretch and fold in taffy pull, egg beater and static mixer, shear stretch, stretch of laminae in a vortex, mixing with diffusion, reaction rate controlled by diffusion of reactant through a product layer, and very fast reactions in a turbulent flow. SCOPEMixing, diffusion, and reaction of soluble fluids have been analyzed primarily in a fixed frame of reference and in terms of the statistical descriptions and theories of fluid mechanics or in terms of variables of distributed value such as residence time. The objective here is to introduce in terse form a type of description and analysis which results in deterministic and predictive models capable of

Impingement mixing is the unique feature of the reaction injection molding (RIM) process but mixheads are largely designed by trial and error. To visualize the impingement process we have taken high speed photographs. To characterize mixing quality we have followed adiabatic temperature rise of mixtures, varying Reynolds number, mixhead geometry and the reaction rate. These results are examined in terms of a simplified model which includes both fluid mechanical and polymerization aspects of the problem.

No abstract

New approaches to studies of spray systems were demonstrated by a series of experiments involving liquid jets spraying in liquids. Attention was focused on those conditions where the stresses causing breakup arose from the inertia of the surroundings and where the induced motion of the surroundings controlled the characteristics of the spray zone in front of the orifice. Experiments and analysis involved principle of balanced stresses, dispersion angle, motion of induced phase, development of spray zone, and drop size.