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...

Turbulent heat transfer in Helically Corrugated Tubes (HCT) was numerically investigated for pure water and SiO2 nanofluid using Computational Fluid Dynamics (CFD). This study was carried out for different corrugating pitches (5, 7, 8 mm) and heights (0.5, 0.75, 1.25 mm) at various Reynolds numbers ranging from 5000 to 13300. The effect of nanoparticles on heat transfer augmentation for plain t...

Abstract: During solidification and casting in metallic molds, the heat flow is controlled by the thermal resistance at the casting-mold interface. Thus heat transfer coefficient at the metal- mold interface has a predominant effect on the rate of heat transfer. In some processes such as low pressure and die-casting, the effect of pressure on molten metal will affect the rate of heat transfer a...

The most important reason for the design of curved tubes is increasing the heat transfer between the fluid and the wall which has provided many applications in various industries such as air conditioning, micro-electric, heat exchangers and etc. The aim of this study is numerical investigation of nano fluids flow in spiral tubes with injection of base fluid in different Reynolds numbers. Accord...

In order to examine the laminar convective heat transfer of nanofluid, experiments carried out using silver-oil nanofluid in a concentric annulus with outer constant heat flux as boundary condition. Silver-oil nanofluid prepared by Electrical Explosion of Wire technique and observed no nanoparticles agglomeration during nanofluid preparation process and carried out experiments. The average size...

A Lagrangian computational method is used to explore the performance of heat exchangers in conditions of oscillating flow and oscillating pressure relevant to thermoacoustic devices. Pressure oscillations cause temperature oscillations within the working gas. Depending on phase, these ‘‘pressure-driven temperature oscillations’’ can enhance or degrade heat transfer within the exchangers of a th...

Heat transfer enhancement technology has the aim of developing more efficient systems as demanded in many applications. An available passive method is represented by the employ of rough surfaces. Transversal turbulators enhance the heat transfer rate by reducing the thermal resistance near surfaces, because of the improved local turbulence; on the other hand, higher losses are expected. In this...

The investigation of a capillary-based heat exchanger is presented for potential integration with thermoelectric devices and thermal energy harvesting. The exchanger is a microfabricated device, designed to promote phase change of low boiling-point working fluids and enhance heat transfer from thermoelectric de-

Nanofluid is a new class of heat transfer fluids engineered by dispersing metallic or non-metallic nanoparticles with a typical size of less than 100 nm in the conventional heat transfer fluids.This article aims to investigate the overall and convection heat transfer coefficient and Nusselt number of Al2O3-water nanofluid flowing in a horizontal double pipe heat exchanger under turbulent flow (...