A NEW HYBRID MIXED FINITE ELEMENT METHOD IS PROPOSED FOR SOLVING THE CONVECTION-DIFFUSION-REACTION EQUATION WITH LOCAL EXPONENTIAL FITTING TECHNIQUE. IN THIS METHOD, THE EXPONENTIAL FITTING TECHNIQUE IN [7] IS USED TO DISCRETIZE THE CONVECTION-DIFFUSION- REACTION EQUATION BY INTRODUCING A NEW VARIABLE AT ELEMENT LEVEL; THEN THE HYBRID MIXED DISCONTINUOUS GALERKIN FINITE ELEMENT METHOD IS USED TO APPROXIMATE THE DISCRETIZED PROBLEM. THE CONVERGENCE OF THE PROPOSED METHOD IS ANALYZED, AND THE CORRESPONDING A PRIORI ERROR ESTIMATE IS DERIVED. THE NUMERICAL RESULTS ARE PRESENTED TO CONFIRM OUR THEORETICAL ANALYSIS.

IN THIS WORK, A TWO-DIMENSIONAL MATHEMATICAL MODEL OF THE MOISTURE TRANSPORT AND STRESS?STRAIN PHENOMENA DURING THE CONVENTIONAL DRYING PROCESS OF EUCALYPTUS NITENS WOOD IS PRESENTED. THE MODEL CONSISTS OF A SYSTEM OF PARTIAL DIFFERENTIAL NONLINEAR SECOND-ORDER EQUATIONS, WHERE THE MOISTURE TRANSPORT PHENOMENON IS MODELED ON THE CONCEPT OF EFFECTIVE DIFFUSION, AND THE STRESSES ARE MODELED ON THE HYPOTHESIS OF VISCOELASTIC DEFORMATION, WHICH IS STRONGLY LINKED TO THE STRAINS BY FREE CONTRACTION AND MECHANO-SORPTION. THE DRYING WAS ASSUMED AS AN ISOTHERMAL PROCESS AND WITHOUT EFFECTS OF SUSTAINED LOADS OVER TIME (CREEP). EXPERIMENTAL TESTS WERE ALSO CARRIED OUT UNDER CONSTANT PSYCHOMETRIC CONDITIONS AT 30/25 (°C/°C) IN ORDER TO OBTAIN TRANSIENT DISTRIBUTIONS OF MOISTURE AND STRESS. FROM THESE EXPERIMENTAL DATA, THE PHYSICAL PARAMETERS OF THE PROPOSED MATHEMATICAL MODEL WERE OBTAINED BY OPTIMIZATION IN A CONTEXT OF INVERSE PROBLEM. THE NUMERICAL SOLUTION OF THE MODEL WAS OBTAINED THROUGH THE METHOD OF CONTROL VOLUMES COMBINED WITH FINITE ELEMENTS. THE RESULTS OF TRANSIENT DISTRIBUTION OF MOISTURE AND STRESS CORRELATE WELL WITH THE EXPERIMENTAL DATA.