Heat transfer characteristics of water flowing through micro-tube heat exchanger with variable fluid properties

Journal of Thermal Analysis and Calorimetry - The heat transfer characteristics of laminar single-phase forced convective water flow through a micro-tube heat exchanger are numerically investigated...     

An experiment study on fluid heat and mass transfer properties in porous media using MRI

The objective of this study was to understand fluid heat and mass transfer processes in porous media with different pore structures. High-resolution Magnetic Resonance Imaging was used to measure fluid flow velocity and temperature maps in porous media. Firstly, three orthogonal velocity components (V _x , V _y , and V _z ) of single phase flow measurement were evaluated. The flow distribution in porous media is rather heterogeneous, and it is consistent with heterogeneous pore structure, and the velocity in large pore is high. Then we presented initial results from the extension of this work to two-phase flow. The CO₂ channeling phenomena were obvious. And the CO₂ velocity was calculated from saturation of water. Finally, the linearity relationship between temperature and the MRI parameter was determined for porous media, and we measured the temperature distribution of water saturated porous media. The study provides useful data for heat and mass process during CO₂ storage.     

Impact of heat and mass transfer on the peristaltic mechanism of Jeffery fluid in a non-uniform porous channel with variable viscosity and thermal conductivity

Journal of Thermal Analysis and Calorimetry - The present examination emphasizes the effects of heat and mass transfer on the peristaltic flow of Jeffery fluid through a non-uniform channel with...     

Hydrodynamics of a bounded vertical film with nonlinear surface properties

The drainage of a thin liquid film with an insoluble monolayer down a vertical wall is studied. Lubrication theory is used to develop a model where the film is pinned at the top with a given thickness and the film drains into a bath at the bottom. A nonlinear equation of state is used for the surface tension and the surface viscosity is a nonlinear function of the surfactant concentration; these are appropriate for some aqueous systems. The three partial differential equations are solved via discretization in space and then the resulting differential algebraic system is solved. Results are described for a wide range of parameters, and the conditions under which the free surface is immobilized are discussed.     

Thermal radiation impact on magneto-hydrodynamic heat transfer micropolar fluid flow over a vertical moving porous plate: A finite difference approach

For this research, an examination on the magnetohydrodynamic flow of a micropolar fluid across a moving vertical porous plate for the presence of thermal radiation is achieved. It is necessary to translate the partial differential equations regulating the flow, heat, & mass transfer into dimensionless form employing proper non-dimensional variables, which are then cracked numerically by utilizing the Finite difference approach. Graphs are used to represent numerical values of various flow profiles; however, tables are used to represent the simulated values of rate coefficients. The velocity rises when the value of Grashof number, dimensionless viscosity ratio is raised, and the opposite effect is seen when the value of magnetic parameter, micro-gyration factor is raised. The result in skin friction coefficient improves when the values of magnetic parameter, micro-gyration factor, Prandtl number, and radiation are raised higher.     

Forced convection heat transfer of nanofluids from a horizontal plate with convective boundary condition and a line heat source embedded in porous media

Journal of Thermal Analysis and Calorimetry - In this study, forced convective flow of nanofluids over a horizontal flat plate with convective boundary condition and a heated line source which are...     

Heat transfer of viscous fluid in a vertical channel sandwiched between nanofluid porous zones

Journal of Thermal Analysis and Calorimetry - Mixed convection in vertical parallel channels is analyzed with the viscous fluid sandwiched between nanofluids within porous material filled in a...     

Entropy generation analysis in a microchannel Poiseuille flows of nanofluid with nanoparticles injection and variable properties

Journal of Thermal Analysis and Calorimetry - In this study, a more realistic, modified Buongiorno’s nanofluid model is suggested and used to examine the impact of nanoparticle injection and...     

Influence of hybrid nanofluids and heat generation on coupled heat and mass transfer flow of a viscous fluid with novel fractional derivative

Journal of Thermal Analysis and Calorimetry - In this paper, it has been discussed a nonlocal fractional model of viscous nanofluid holding a hybrid nanostructure. Hybridized copper (Cu) and...     

Saccharose effects on surface association of phenol derivatives with porous graphitic carbon

In this paper, the effect of saccharose on the association of phenol derivatives on both the porous graphitic carbon (PGC) surface and the C18 stationary phase and for two methanol fractions (v/v) in the mobile phase is described. A novel approach based on an extended Langmuir distribution isotherms was used. The results demonstrated that: (i) the saccharose can be adsorbed on the PGC surface; (ii) the phenol derivatives can be associated with saccharose adsorbed on the PGC surface; and (iii) the saccharose do not interact with the C18 stationary phase. This was confirmed by the thermodynamic data and the Wyman equation parameters.     

Steady hydromagnetic flow of a non-Newtonian power law fluid due to a rotating porous disk with heat transfer

The steady magnetohydrodynamic (MHD) flow of an incompressible viscous non-Newtonian power law fluid above an infinite rotating porous disk with heat transfer is studied. A uniform magnetic field is applied perpendicularly to the plane of the disk and a uniform injection or suction is applied through the surface of the disk. Numerical solutions of the nonlinear differential equations which govern the hydromagnetic and heat transfer are obtained. The effects of characteristics of the non-Newtonian fluid, the magnetic field parameter and the suction or injection velocity on the velocity and temperature distributions are considered.     

Scaling group analysis of bioconvective micropolar fluid flow and heat transfer in a porous medium

Journal of Thermal Analysis and Calorimetry - The current and potential applications of bioconvection renewed drive for theoretical research on synthesis and process control in biofuel cells and...     

Effect of thin porous copper coating on the performance of wickless heat pipe with R134a as working fluid

Journal of Thermal Analysis and Calorimetry - The heat transfer characteristics of a thin porous copper-coated wickless heat pipe using R134a as a working fluid is investigated and is...     

Gravimetric characterisation of the surface properties of a porous drug carrier

The gas adsorption method is the most common means to characterise the topology of solid surfaces with regard to its use as an adsorbent. Adsorption isotherms are determined advanta-geously using a vacuum microbalance: Thermogravimetric techniques allow the observation of sample degassing and its optimization. The dry mass is determined in situ, the mass of gas adsorbed is measured directly and different gases can be used without calibration. From the isotherm the pore size distributions, specific surface area, fractal dimension and density can be derived. Commercially available gravimetric sorption apparata and vacuum balances as well as software for data evaluation are reviewed in tables. The sorption analysis of an aluminum oxide is presented. The porous material was used as a matrix for a slow drug release.     

Thermal analysis of electroosmotic flow in a vertical ciliated tube with viscous dissipation and heat source effects

Journal of Thermal Analysis and Calorimetry - Thermal analysis of electroosmotic flow of Newtonian fluid in the presence of viscous dissipation and heat source in a vertical ciliated tube is...     

Three-dimensional numerical simulation of external fluid flow and heat transfer of a heat exchanger in a wind tunnel using porous media model

Journal of Thermal Analysis and Calorimetry - Notwithstanding the widespread use of wind tunnel to investigate the performance of radiators and heat exchangers, has never been considered a...     

Computational study on the effects of variable viscosity of micropolar liquids on heat transfer in a channel

Journal of Thermal Analysis and Calorimetry - A numerical model is developed to study the effects of temperature-dependent viscosity on heat transfer in magnetohydrodynamic flow of micropolar fluid...     

Natural convection heat transfer and entropy generation in a porous rhombic enclosure: influence of non-uniform heating

Journal of Thermal Analysis and Calorimetry - In this paper, we present a numerical investigation of natural convection heat transfer and entropy generation for a rhombic enclosure with inclination...     

Numerical investigation on the effect of magnetic field on natural convection heat transfer from a pair of embedded cylinders within a porous enclosure

The present work examines the influence of magnetohydrodynamic field on natural convection phenomena inside a porous square enclosure with a pair of embedded hot circular cylinders. Numerical investigations are performed to understand the effects of interspacing distance between the embedded cylinders, Hartmann number, Rayleigh number and Darcy number on the thermal transport process and the total irreversibility generation. It is observed that the isotherm distribution is strongly affected by the presence of magnetic field although the distribution of streamlines remains independent of the strength of magnetic field. This underlines the fact that magnetic field strongly influences the heat transfer process and entropy generation characteristics. It reveals that the natural convection is suppressed in the presence of a higher magnetic field as evident from the reduction in Nusselt number. It is observed that an increase in the spacing between the cylinders increases the heat transfer rate, and moreover, the effect of the magnetic field on heat transfer is more pronounced at higher interspacing distance between the embedded cylinders. The heat transfer rate increases significantly with the increase in the permeability of the medium. The entropy generation rate is independent of the strength of applied magnetic field. Further, the contribution of the entropy generation owing to friction is found to be negligible in total irreversibility obtained at lower values of Rayleigh number irrespective of Darcy number. However, the contribution of irreversibility owing to heat transfer is found to be minimal at higher values of Rayleigh number.