Bubble columns are gas- liquid contactors that are widely used in chemical and bio- chemical industries. High mixing that result in high heat and mass transfer rates are amongst their advantages. Heat transfer in a bubble column having a bundle of heaters investigated and the variation of heat transfer coefficient with variation in heaters pitch to diameter ratios in a bundle of heaters reporte...

The heat and mass transfer processes in direct contact membrane distillation (MD) under laminar flow conditions have been analyzed by computational fluid dynamics (CFD). A two-dimensional heat transfer model was developed by coupling the latent heat, which is generated during the MD process, into the energy conservation equation. In combination with the Navies-Stokes equations, the thermal boun...

Steady heat transfer through a pin fin is studied. Thermal conductivity, heat transfer coefficient, and the source or sink term are assumed to be temperature dependent. In the model considered, the source or sink term is given as an arbitrary function. We employ symmetry techniques to determine forms of the source or sink term for which the extra Lie point symmetries are admitted. Method of sep...

Finite-time thermodynamic models for an Otto cycle, an Atkinson cycle, an over-expansion Miller cycle (M1), an LIVC Miller cycle through late intake valve closure (M2) and an LIVC Miller cycle with constant compression ratio (M3) have been established. The models for the two LIVC Miller cycles are first developed; and the heat-transfer and friction losses are considered with the effects of real...

in this study, the natural convection heat transfer of variable properties al2o3-eg-water nanofluid in a differentially heated rectangular cavity has been investigated numerically. the governing equations, for a newtonian fluid, have been solved numerically with a finite volume approach. the influences of the pertinent parameters such as ra in the range of 103-107 and volume fraction of nanopar...

Heat transfer coefficient in nucleate pool boiling near critical heat flux at least one orderhigher than the convectional heat transfer modes. In this paper, an experimental setup isdesigned and fabricated to investigate the mechanism of heat transfer from boiling surface tobulk liquid near critical heat flux. The images of pool boiling near the high heat flux regionreveals that the individual ...

Three different profiles of the straight fin that has a temperature-dependent thermal conductivity are investigated by differential transformation method DTM and compared with numerical solution. Fin profiles are rectangular, convex, and exponential. For validation of the DTM, the heat equation is solved numerically by the fourth-order Runge-Kutta method. The temperature distribution, fin effic...

Improving heat transfer and performance in a radial, finned, shell and tube heat exchanger is studied in this study. According to the second law of thermodynamics, the most irreversibilities of convective heat transfer processes are due to fluid friction and heat transfer via finite temperature difference. Entransy dissipations are due to the irreversibilities of convective heat transfer. There...