Universidade do Minho –
Departamento de Engenharia Biológica
Campus de Gualtar
4710-057 Braga
Portugal

In this work the residence time distributions (RTD) of water (a Newtonian fluid) and a carboxy-methyl-cellulose – CMC (with non-Newtonian rheology) continuously fed to a pilot scale ohmic heater will be numerically simulated using a computational fluid dynamic (CFD) model. The use of the distribution functions allows visualising the flow patterns inside the continuous ohmic heater leading to the determination of mixing efficiencies and estimation of deviation from a plug flow behaviour. In order to achieve this, the rheology of the CMC solution was experimentally determined and included in the CFD flow model using Fluent software (Fluent Inc., New York, USA). The objective is to finally characterise the flow inside the heater under different circumstances.

Months 1 and 2: Bibliography search and adaptation to the computer code to be used (Fluent)
Months 3 to 5: Simulations, using Fluent, of several flow conditions with different fluids (Newtonian and non-Newtonian); determination of the velocity fields, pressure fields, etc. Experimental validation of the results obtained with the simulations.
Month 6: Report generation.

Reis, N., Harvey, A.P., Mackley, M.R., Vicente, A.A., Teixeira, J.A. Fluid Mechanics and Design Aspects of a Novel Oscillatory Flow Screening Mesoreactor. Transactions of Institution of Chemical Engineers, Part A: Chemical Engineering Research and Design, 83(A4), 357-371, 2005. Reis, N., Vicente, A.A., Teixeira, J.A., Mackley, M.R., Residence times and mixing of a novel continuous oscillatory flow screening reactor, Chem. Eng. Sci., 59, 4967-4974, 2004.