COBEM99

S25 Métodos Numéricos

Title:

THE FINITE-VOLUME APPROACH FOR THE SOLUTION OF THE TRANSIENT DIFFUSION EQUATION APLLIED TO PROLATE SPHEROIDAL SOLIDS PROLATE SPHEROIDAL SOLIDS

Summary :

A NUMERICAL SOLUTION OF THE DIFFUSION EQUATION TO DESCRIBE HEAT OR MASS TRANSPORT INSIDE ELLIPSOIDS, CONSIDERING VARIABLE DIFFUSION COEFFICIENT AND CONVECTIVE BOUNDARY CONDITION, IS PRESENTED. THE DIFFUSION EQUATION IN PROLATE SPHEROIDAL COORDINATE SYSTEM FOR A BIDIMENSIONAL CASE, WAS USED. A FINITE VOLUME METHOD WAS EMPLOYED TO DISCRETIZE THE BASIC EQUATION UTILIZING A UNIFORM GRID SIZE. THE EQUATION WAS SOLVED ITERATIVELY BY THE GAUSS-SEIDEL METHOD. TO VALIDATE THE NUMERICAL MODEL, THE RESULTS OBTAINED WERE COMPARED WITH THE ANALYTICAL SOLUTION. THE MODEL WAS USED TO SOLVE THE CASE OF WHEAT GRAIN DRYING, THE RESULTS WERE COMPARED WITH EXPERIMENTAL DATA. THIS TECHNIQUE CAN BE ALSO APPLIED IN THE PROCESSING OF PRODUCTS WITH VARIABLE PROPERTIES DURING DIFFERENT PROCESS (DRYING, WETTING, HEATING AND COOLING). THE RESULTS SHOW ALSO THAT THE MODEL IS CONSISTENT AND IT MAY BE USED TO SOLVE OTHER CASES, LIKE THOSE WHICH INCLUDE CYLINDER AND SPHERE GEOMETRY AND/OR THOSE WITH OTHER BOUNDARY CONDITIONS, WITH SMALL MODIFICATIONS

Author :

Lima, Antonio Gilson
Nebra, Silvia Azucena

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