if an air flow is injected into a liquid fluid, many ambulant air bubbles are formed inside the fluid. air bubbles move inside the liquid fluid because of the buoyancy force, and the mobility of these air bubbles makes sizable commixture and turbulence inside the fluid. this mechanism was employed to enhance the heat transfer rate of a horizontal double pipe heat exchanger in this paper. howeve...

A numerical investigation has been carried out applying single phase approach on turbulent forced convection flow of water based Al2O3 and TiO2 nanofluids flowing through a horizontal circular pipe under uniform heat flux boundary condition applied to the wall. The effect of volume concentrations, Brownian motion and size diameter of nanoparticles on flow and heat transfer have been examined fo...

A solution layer crystallization process in a concentric annulus is presented that removes the need for filtration. A dynamic model for layer crystallization with and without a recirculation loop is developed in the form of coupled partial differential equations describing the effects of mass transfer, heat transfer, and crystallization kinetics. The model predicts the variation of the temperat...

Different control strategies of bed temperature and moisture were investigated using various inlet air temperatures and air fluxes in both the ordinary packed bed bioreactor (without cooling water in the jacket) and the bioreactor with cooling water in jacket. The experiments were carried out within a 1-L solid-state packed bed bioreactor in which Aspergillus niger was cultivated on wheat bran....

The fluid flow and heat transfer in lid-driven enclosures filled with Cu-water nanofluid is numerically investigated. The moving vertical walls of the enclosure  are maintained in a constant temperature, while the horizontal walls are insulated. The hybrid scheme is used to discretize the convection terms and SIMPLER algorithm is adopted to couple the velocity field and pressure in the momentum...

In this paper, the natural convection heat transfer of Al2O3-EG-water nanofluid in a rectangular cavity which is heated from the bottom and is cooled from the top has been investigated numerically. The governing equations for a Newtonian fluid have been solved numerically with a finite volume approach using the SIMPLER algorithm. The main focus of the current study is on the effects of variable...

An evacuated tube solar collector using therminol D-12 as heat transfer fluid coupled with parabolic trough is studied in this paper. An experimental set-up was constructed to study the performance of evacuated tube collector with therminol D-12 as heat transfer fluid. The parabolic trough is coupled with evacuated tube collector for better performance. In the traditional solar collectors water...

We report a novel boiling heat transfer (NBHT) in reduced graphene oxide (RGO) suspended in water (RGO colloid) near critical heat flux (CHF), which is traditionally the dangerous limitation of nucleate boiling heat transfer because of heater failure. When the heat flux reaches the maximum value (CHF) in RGO colloid pool boiling, the wall temperature increases gradually and slowly with an almos...