FOR THE FIRST TIME, COMPUTATIONAL FLUID DYNAMICS TECHNIQUE IS APPLIED TO DYNAMICALLY SIMULATE CATALYTIC REFORMING RECTORS ON INDUSTRIAL SCALE. TRANSPORT PHENOMENA FOR MOMENTUM, HEAT, MASS AND TURBULENCE ARE SIMULTANEOUSLY SOLVED THROUGH THE DOMAIN OF FLUID. ADDITIONALLY, HEAT TRANSFER EQUATION IS SOLVED FOR SOLID-STATE REGIONS. TWENTY-FOUR IRREVERSIBLE REACTIONS INVOLVING FOUR PSEUDO-COMPONENTS IN THE FEEDSTOCK, NAMELY AROMATICS, NAPHTHENES, PARAFFINS AND COKE, ARE CONSIDERED TO OCCUR INTO THE CATALYTIC BEDS. ALL REACTIONS ARE TREATED AS ARRHENIUS TYPE WHEN ACTING AS STIFF CLASS OF ORDINARY DIFFERENTIAL EQUATION IN THEIR SOLUTION PROCEDURE. COKE FORMATION IS TAKEN INTO ACCOUNT FOR THE FIRST TIME WITH TWO PRESSURE-DEPENDENT REACTIONS. THE KINETIC SCHEME IS OBTAINED FROM NUMEROUS EXPERIMENTS ESTABLISHED ON THE PILOT PLANT AND ITS PARAMETERS ARE ADJUSTED TO THE PLANT DATA. RESULTS SHOW GOOD AGREEMENT BETWEEN SIMULATION AND PLANT DATA SO THAT MAXIMUM RELATIVE ERROR REACHED FOR RESEARCH OCTANE NUMBER IS LESS THAN 2 PER CENT.

IN THIS ARTICLE THE COMPUTATIONAL PREDICTIONS OF NREL PHASE VI ROTOR IS DONE. THE MODEL IS A STALL REGULATED TWO BLADED WIND TURBINE WITH LINEAR TAPER AND NONLINEAR TWIST DISTRIBUTION AND USES THE S809 AIRFOIL FROM ROOT TO TIP. THE EXPERIMENTAL TESTS WERE DONE IN THE NASA/AMES 80 FT. X 120 FT. ALL THE SIMULATIONS OF THIS PAPER ARE PERFORMED USING THE COMMERCIAL SOLVER ANSYS FLUENT 15.0. THE COMPARISONS ARE DONE FOR THE BLADE WITH 3 DEGREE TIP PITCH ANGLE AND RESULTS OVER WIND SPEEDS RANGING FROM 5M/S TO 20 M/S SHOWS THE CAPABILITY OF CFD IN PREDICTING COMPLEX AERODYNAMICS OF WIND TURBINES.

A BUBBLE COLUMN REACTOR IS A MULTIPHASE FLOW REACTOR IN WHICH REACTANT GAS IS BUBBLED THROUGH A LIQUID SOLUTION. BUBBLE COLUMN REACTORS MAY BE OPERATED IN A BATCH OR CONTINUOUS MODE. THEY ARE KNOWN AS EXCELLENT REACTORS FOR PROCESSES, WHICH REQUIRE LARGE INTERFACIAL AREA FOR GAS-LIQUID MASS TRANSFER AND EFFICIENT MIXING FOR REACTING SPECIES FOR EXAMPLE IN BUBBLE COLUMN FERMENTORS. A BETTER KNOWLEDGE OF THE LOCAL HYDRODYNAMICS TO INCREASES THE PREDICTABILITY OF THE REACTOR DESIGN AND TO IMPROVE THE EFFICIENCY OF THE PROCESSES APPEARS CURRENTLY NECESSARY. THE USE OF NUMERICAL MODELING I.E. COMPUTATIONAL FLUID DYNAMICS (CFD) SHOULD BE ABLE TO IMPROVE THIS KNOWLEDGE BY PROVIDING A COMPLETE DESCRIPTION OF THE LOCAL HYDRODYNAMICS IF AN ADEQUATE MODEL IS USED. IN THIS RESEARCH, HYDRODYNAMIC BEHAVIOR OF BUBBLE COLUMN REACTOR WAS DETERMINED. IN PREVIOUS WORKS, THE PREDICTION OF GAS HOLDUP IS NOT ACCURATELY COVERED. FOR THAT REASON, THE TURBULENCY IN LIQUID PHASE IS MODELED BY STANDARD K-E MODEL. IN ADDITION, LOCAL AXIAL VELOCITY, VELOCITY DISTRIBUTION AND LOCAL GAS HOLD-UP WERE CALCULATED BY FLUENT 6.0.3, WHICH IS COMMERCIAL SOFTWARE. THE RESULTS HAVE BEEN COMPARED WITH EXPERIMENTAL DATA, WHICH SHOWS A QUITE GOOD AGREEMENT.

NATURAL CONVECTION IN ENCLOSURES IS COUNTED AS AN IMPORTANT PHENOMENON IN MANY ENGINEERING APPLICATIONS. THIS PAPER NUMERICALLY INVESTIGATES NATURAL CONVECTION FLOW FIELD AND HEAT TRANSFER OF DIFFERENT TURBULENT MODELS. STANDARD K-E, STANDARD K-W AND SHEAR STRESS TRANSPORT MODEL (SST) HAVE BEEN COMPARED WITH EXPERIMENTAL DATA. THE CAVITY IS PARTIALLY HEATED. THE COMMERCIAL CFD CODES, ANSYS FLUENT, ARE EMPLOYED. STANDARD K-W MODEL PROVIDED GOOD AGREEMENT WITH THE EXPERIMENTAL DATA.

COMPUTATIONAL FLUID DYNAMICS (CFD) HAS BECOME AN EFFECTIVE TOOL FOR PREDICTING DETAILED FLOW INFORMATION IN TURBINE SPACE. IN THIS STUDY, PREDICTION OF FLOW PARAMETERS FOR FRANCIS TURBINES IS PRESENTED. TO AIM THIS PURPOSE, FOUR DIFFERENT RUNNER TRAILING EDGES ARE DESIGNED AND FIVE POINTS ARE SET ON EACH AS ‘FIXED MEASURING POINTS’ TO REPORT THE FLOW PARAMETERS. THE OBTAINED RESULTS ARE IN GOOD AGREEMENT WITH THE IN SITE EXPERIMENTS.