In order to improve the efficiency and rate of heat transfer in heat exchangers, various techniques such as increasing the heat transfer coefficient are proposed. This study is devoted to the investigation of heat transfer coefficient variations due to the addition of CuO, TiO2 and CuO/TiO2 nanoparticles into a shell and tube heat exchanger. CuO/TiO2 nanocomposite was synthesized using mechanic...

An experimental investigation was conducted to study the average and the fully-developed heat (mass) transfer coefficients in a rectangular smooth duct and a duct with repeated-baffle blockages. The focus of attention in this work is the conventional correlation Nu / Nufd 1 + C / ( X / D ) for the average heat transfer coefficient. It was shown that for relatively short ducts, the coefficient C...

An analytical investigation is conducted to study the unsteady free convection heat and mass transfer flow through a non-homogeneous porous medium with variable permeability bounded by an infinite porous vertical plate in slip flow regime while taking into account the thermal radiation, chemical reaction, the Soret number, and temperature gradient dependent heat source. The flow is considered u...

Fouling is a common, fundamental and costly problem in heat transfer systems, which reduces thermal efficiency of equipment, increases the energy loss and causes strong damage to the heat transfer equipment in various industries. The main causes of fouling on the heat transfer surfaces are salts with inverse temperature-solubility in the fluid which calcium sulfate is one of the most important ...

An analytical study was performed to study effects of thermo-diffusion and chemical reactions on a three-dimensional MHD mixed convective flow of dissipative fluid along an infinite vertical porous plate with transverse sinusoidal suction velocity. The parabolic partial differential equations governing the fluid flow, heat transfer, and mass transfer were solved using perturbation technique and...

in this paper, we have considered the problem of rotating, magnetohydrodynamic heat and mass transfer by free convective flow past an exponentially accelerated isothermal vertical plate in the presence of variable mass diffusion. while the temperature of the plate is constant, the concentration at the plate is considered to be a linear function with respect to time t. the plate is assumed to be...

the present paper describes the designing of a thermally and economically optimum mechanical draft counter-flow wet cooling tower. the design model allows the use of a variety of packing materials in the cooling tower toward optimizing heat transfer. once the optimum packing type is chosen, a compact cooling tower with low fan power consumption is modelled within the known design variables. mor...

a one–dimensional, transient and thermal degradation model for predicting responses of composite materials when are exposed to the fire is presented. the presented model simulates ablation of composites with different layers of materials and considers material properties as functions of temperature. the reactions are modeled by using arrhenius-type parameters and density-temperature diagrams wh...

in this work, the characteristics of flow and heat transfer of a fluid containing nano particles of aluminum oxide with the water volume fraction (0.1-0.2-0.3)(v/v) percent of the reports. the overall heat transfer coefficient, heat transfer and the average heat transfer fluid containing nano water - aluminum oxide in a horizontal double pipe counter flow heat exchanger under turbulent flow con...

a numerical model is developed to simulate the transport phenomena in the flow channel between parallel plates with porous and non-porous (or impermeable) walls. the continuity and momentum equations were solved first, assuming the wall reynolds number in the range of with the suction or injection of air at a speed equal to the uniform inlet velocity. the results show that at constant inlet and...