The present study attempts to improve heat transfer efficiency of a domestic gas burner by enhancing heat transfer from flue gases. Heat transfer can be augmented using the obstacles that are inserted into the flow field near the heated wall of the domestic gas burner. First, to achive the maximum efficiency, the insert geometry is optimized by the multi-objective genetic algorithm so that heat...

In the present research, free convection heat transfer from isothermal concave and convex body shapes is studied numerically. The body shapes investigated here, are bi-sphere, cylinder, prolate and cylinder with hemispherical ends; besides, they have the same height over width (H/D = 2). A Numerical simulation is implemented to obtain heat transfer and fluid flow from all of the geometries in a...

This reports the study on the flow behaviour, heat transfer and contamination distribution in a room. For this purpose the 3-D incompressible Navier-Stokes equations, energy equation and a mass transfer equation which model the concentration of contamination have been applied. For turbulence simulation the two equation standard k-  turbulence model was employed. By means of SIMPLE algorithm the...

cooling towers are widely used in most industrial units to reject waste heat to the atmosphere. this paper deals with an experimental analysis of heat and mass transfer phenomena between water and air by direct contact in a cooling tower. the tower is filled with 6 type packing. in this study temperature and pressure drop and tower characteristics was used in determining experimentally the ther...

Fe3O4 nanofluid fully developed forced convection inside a copper tube is empirically investigated under the effect of a magnetic field. All of the investigations are performed under laminar flow regime (670≤Re≤1700) and thermal boundary conditions of the tube with uniform thermal flux. The tube is under the effect of a magnetic field in certain points. This research aims to study the effect of...

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...

This study discusses the application of Taguchi method in assessing minimum entropy generation and maximum heat transfer rate for natural convection in an enclosure embedded with isothermal cylinder. The simulations were planned based on Taguchi’s L25 orthogonal array with each trial performed under different conditions of position and aspect ratio (AR) of the cylinder. The thermal lattice Bolt...

This study presents an innovative and simple way to increase the rate of heat transfer in a spiral plate heat exchanger model. Several circular cross-section rods, as continuous vortex generators, have been inserted within the spiral plate heat exchanger in the cross-stream plane. The vortex generators are located at various azimuth angles of α=30◦, 60◦, 90◦, and 120◦ with non-dimensional diame...

in the present study, turbulent flow in channels of a plate heat exchanger with corrugated chevron plates has been simulated numerically using the commercial cfd package, fluent. unstructured mesh is used for discretizing the computational domain and simple algorithm is utilized to solve the pressure and velocity equations. there is a wide selection of different plate heat exchangers within the...

In this paper, convection heat transfer of Al2O3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. For each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. The governing equations in...