in this paper the numerical analysis of flow and time dependent heat transfer of micro-tube conveying nanofluid in laminar flow is investigated. in this study, convection heat transfer of nanofluid and base fluid and transient analysis for time-varying heat flux for time step of 0.0001 second are elucidated. it is observed that the pumping power of nanofluid flowing and the maximum temperature ...

the effect of γ-al2o3 nanoparticles on heat transfer rate, baffle spacing and pressure drop in the shell side of small shell and tube heat exchangers was investigated numerically under turbulent regime. γ-al2o3-water nanofluids and pure water were used in the shell side and the tube side of heat exchangers, respectively. since the properties of γ-al2o3-water nanofluids were variable, they were ...

Passive phase-change thermal spreaders such as vapor chambers have been widely employed to spread the heat from small-scale high-flux heat sources to larger areas. In the present work, a numerical model for ultra-thin vapor chambers has been developed which is suitable for reliable predictions of the operation at high heat fluxes and small scales. The effects of boiling in the wick structure on...

The flow of gas in the suction chamber of an air brake compressor was analyzed, and losses due to pressure drop and heat transfer were identified by CFD simulations. Based on the results of the calculations the geometry of the suction chamber was modified to investigate possible improvements. Due to simple design modifications the flow direction of the gas was changed, which resulted in a reduc...

The scale up of an isothermal micro-trickle bed reactor operated under radio frequency (RF) heating has been performed. The effect of the reactor length, tube diameter and number of parallel tubes on the temperature non-uniformity parameter has been studied. The axial and radial temperature profiles were calculated using a 2D convection and conduction heat transfer problem with heat transfer pr...

Magnetohydrodynamics (MHD) stagnation point flow and heat transfer of a Williamson fluid in the direction of an exponentially stretching sheet embedded in a thermally stratified medium subject to suction present in this examination. Suitable transformations are used to convert the partial differential equations corresponding to the momentum and energy equations into highly nonlinear ordinary di...

In this work time dependent heat transfer flow through a kerosene based ferrofluid is considered. The flow is in a cylindrical geometry with the height and diameter of 10 mm. Computational fluid dynamics was used to simulate the system. In CFD simulations mixture model was applied to describe the behavior of the magnetic particles. A uniform magnetic field with different strengths and direction...

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...