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...

In this paper we reduce a free boundary problem from heat transfer to a weakly Singular Volterra  integral equation of the first kind. Since the first kind integral equation is ill posed, and an appropriate method for such ill posed problems is based on wavelets, then we apply the Chebyshev wavelets to solve the integral equation. Numerical implementation of the method is illustrated by two ben...

The interaction of thermal radiation with conduction and laminar natural convection in a vertical circular pin, situated at participating gas, is numerically investigated. An absorbing and emitting gas is considered, and treated to be a gray participating media. Under the idealizing of gray gas, the Rosselan4 approximation is employed to describe the radiative heat flux in the energy equation. ...

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...

Why heat and mass transfer ................................................................................................................................1 Fundamentals of heat transfer (what is it) ..........................................................................................................2 Thermodynamics of heat transfer ............................................................

Reduced Basis (RB) method has successfully been used in 2D to solve heat transfer parametrized problems. In this work, we present some 3D applications in the same field. We consider two problems, the steady Thermal Fin and the time dependent Graetz Flow, we compare two reduced order modelling techniques: RB and Proper Orthogonal Decomposition (POD), then we apply a combination of the two strate...

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...

Why heat and mass transfer ................................................................................................................................1 Fundamentals of heat transfer (what is it) ..........................................................................................................2 Thermodynamics of heat transfer ............................................................

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...