In this paper, mixed forced and natural convection heat transfer in a rectangular cavity has been numerically studied. the cavity receives a uniform heat flux from one side and is ventilated with a uniform external flow. The external flow enters the cavity from the heated side and leaves the cavity from the opposite side. The velocity and temperature fields and heat transfer rate are determined...

For thermal mixed-convection flows, the Nusselt number is a function of Reynolds number, Grashof number and the angle between the forcedand natural-convection directions. We consider flow over a heated cylinder for which there is no universal correlation that accurately predicts Nusselt number as a function of these parameters, especially in opposing-convection flows, where the natural convecti...

Research on using phase change material (PCM) suspension to improve the heat transfer and energy storage capabilities of thermal systems is booming; however, there are limited studies application PCM in transient natural convection. In this paper, implicit finite difference method was used numerically investigate steady-state convection a square enclosure containing suspension. The following pa...

Abstract An experimental setup is built to determine the thermal conductivity of a mixture KNO3 and NaNO3 with ratio 54-46m% which used in high temperature storage systems. The measurement principle based on transient parallel hot-wire method described standards NBN B 62-202 ISO 8892-2. designed measure around melting (<300°C). Measurements within liquid region show faulty results caused by ...

Sal'nikov's chemical reaction is very simple; it consists of two consecutive first-order steps, yielding a product B from a precursor P via an active intermediate A, in P→A→B. The first of these steps is assumed here to be thermoneutral, with zero activation energy, whilst the second step is taken to be exothermic with a positive activation energy. These properties make this reaction one of the...

in this paper, the effect of the brownian term in natural convection of cuo-water nanofluid inside a partially filled porous cavity, with internal heat generation has been studied. it is assumed that the viscosity and thermal conductivity of nanofluid consists of a static part and a brownian part of which is a function of temperature and the volume fraction of nanofluid. because of internal hea...

Heat dissipation, thermal stresses, size and cost are the key packaging design issues for electronic and optoelectronic instruments. As per defense requirement, instruments are expected to work satisfactorily in the temperature range of -30C to +55C. In this study, we have explored the thermal management of a sealed enclosure, envisaged as housing for handheld instruments, using different activ...

The fast progress has been observed in the development of numerical and analytical techniques for solving convection-diffusion and fluid mechanics problems. Here, a numerical approach, based in Galerkin Finite Element Method with Finite Difference Method is presented for the solution of a class of non-linear transient convection-diffusion problems. Using the analytical solutions and the L2 and ...

Joule-Thomson cooling systems are used in refrigeration and liquefaction processes. There are extensive studies on Joule-Thomson cryogenic systems, but most of them coverage steady state conditions or lack from experimental data. In the present work, transient thermal behavior of Joule-Thomson cooling system including counter current helically coiled tube in tube heat exchanger, expansion valve...