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This paper employs large eddy simulation (LES) to investigate non-premixed flameless oxidation occurring in the IFRF furnace with varying fuel-injection angle. In order to model radiation and combustion using Open FOAM software, finite volume discrete ordinate model and partially stirred reactor are applied whereas the detailed mechanism GRI-2.11 is undertaken represent chemistry reactions. The obtained results are compared with the experimental measurements of Mancini's et al. After ensuring the accuracy of the LES method, the combustion characteristics are examined when using different fuel injection angles into the combustion chamber. The results explain using fuel injection with an angle into the combustion chamber, the net rate of reaction and entropy generation increases. [ABSTRACT FROM AUTHOR]

In this paper, a new application is presented for a helical screw tape insert in a 3D tube. In this application, an eccentricity is created between the centrelines of helical screw tape and tube. Accordingly, the effects of this eccentricity on thermal-hydraulic performance and entropy generation are investigated numerically. A three-dimensional SSTk − ω turbulence model is applied to simulate this problem. All simulations are made for eight values of the eccentricity in the range of 0 to 3.5 and Reynolds numbers in the range of 5000 to 12,000. The calculated results showed that incorporating the helical screw tape near the tube wall (by increasing the eccentricity value) diverts the swirling flow from the core region towards the tube surface where high velocity flow impinges over the tube wall, hence extracting higher amount of thermal energy. Moreover, 42% and 237% increments are observed in the frictional and thermal entropy generations, respectively for an eccentricity in the range of 0 to 3.5. [ABSTRACT FROM AUTHOR]