One way to increase the heat transfer is to use perforated twisted tapes with different hole diameters, which largely improve heat transfer with an increase in the heat transfer area at the constant volume and more mixed flow. In the previous studies, the effect of nanofluids with perforated twisted tapes is less studied. In this work, the performance of water / iron oxide nanofluid in a double...

Natural convection heat transfer from a tube bundle in the indirect water bath heaters is investigated. A computer-code is used for the solution of the governing equations of mass, momentum and energy transfer based on the SIMPLE-C algorithm. Simulations are carried out for the gas pressure station heater of Kermanshah city with various tube bundle arrangements. In order to validate the numeric...

Thermal rectification is a phenomenon in which thermal transport along a specific axis is dependent upon the sign of the temperature gradient or heat current. This phenomenon offers improved thermal management of electronics as size scales continue to decrease and new technologies emerge by having directions of preferred thermal transport. For most applications where thermally rectifying materi...

The main objective of this research is to analyze optimization and the thermal performance of circular porous fins with four different profiles, rectangular, convex, triangular and concave under fully wet conditions. In this research, a linear model was used for the relationship between humidity and temperature. Also, modeling is assumed one-dimensional and the temperature changes only in the d...

the excellent performance of fluidized bed heat exchangers is due to the interaction between particles and heat transfer surface and to the mixing effects in the viscous sublayer. in this paper, the results of experimental investigations on heat transfer for a wide range of newtonian and non-newtonian (shear-thinning power law) fluids are presented. new design equations have been developed for ...

A heat exchanger using nanofluid needs to operate at optimum mass concentration level to get the maximum heat transfer performance. A numerical analysis is performed on the heat transfer and pressure drop of water-based γ-Al2O3 nanofluid gasketed-plate heat exchanger to specify its optimum conditions. Cold water will be heated by γ-Al2O3/water nanofluid. The results showed that optimal volume c...

Neurons in macaque primary motor cortex and dorsal premotor cortex are tuned to movement direction. In humans, neuronal populations tuned to movement direction have recently been described using multivoxel pattern analysis and functional magnetic resonance imaging adaptation. It is unclear, however, to what extent directionally tuned neuronal populations are sensitive to movement amplitude. Her...

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...

this paper describes the theoretical and experimental investigations of the key components and also the performance analysis of a rotary wheel for using as a solid desiccant dehumidifier and also indirect evaporator cooling system. solid desiccants have long been used in dehumidification and cooling systems for energy efficiency or reduce electricity. although many mathematical models on the ro...

The presence of particles in liquid-solid fluidized beds enhances the bed heat transfer, because the movement of the particles leads to an increased turbulence in the system. Moreover, the violent movement of the particles has a positive effect on fouling of the heat transfer surface. The aim of this investigation was to perform systematic measurements of bed voidage and heat transfer coeff...