this paper presents the effect of high environmental heat on behavior of the male charles foster rats. eighty rats were divided into three groups, subjected to (i) acute heat stress (ii) chronic heat stress and (iii) handling control group. animals were exposed to the hot environment in a biological oxygen demand incubator at 38 ± 1ºc (relative humidity 45-50%) for four hours of continuous sing...

The thermal balance analysis is a useful method to determine energy distribution and efficiency of internal combustion (IC) engines. In engines cooling concepts, estimation of heat transfer to brake power ratio, as one of the most significant performance characteristics, is highly demanded. In this paper, investigation of energy balance and derivation of specific heat rejection is carried out e...

introduction drying foods, fruits and vegetables is a suitable method to reduce post-harvest losses of the crops. drying is considered as a simultaneous heat and mass transfer process. various physical, chemical and nutritional changes occur during drying of foods and are affected by a number of internal and external heat and mass transfer parameters. external parameters may include temperature...

the fluid flow and heat transfer in a three-dimensional microchannel filled with al2o3- water nanofluid is numerically investigated. the hybrid scheme is used to discretize the convection terms and simpler algorithm is adopted to couple the velocity and pressure field in the momentum equations. the thermal and flow fields were analyzed using different volume fractions of nanoparticles and diffe...

The convective heat transfer and pressure drop of water based Al2O3 nanofluid in a horizontal tube subject to constant wall temperature condition is investigated by computational fluid dynamic (CFD) method. The Al2O3 nanofluid at five volume concentration of 0.1, 0.5, 1.0, 1.5 and 2 % are applied as a non Newtonian power law and Newtonian fluid with experimentally measured properties of density...

conv hAs (Ts T ) where As is the heat transfer surface area and h is the convection heat transfer coefficient. When the temperatures Ts and T are fixed by design considerations, as is often the case, there are two ways to increase the rate of heat transfer: to increase the convection heat transfer coefficient h or to increase the surface area As. Increasing h may require the installation of a p...

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...

Project Overview Interrupted-fin surfaces are used to enhance the air-side heat transfer performance in many compact heat exchangers. While many empirical correlations are available in the open literature for offset-strip and louvered-fin geometries, local heat transfer behavior on individual fins is not as well understood. A redesign of these surfaces may result in higher heat transfer. Inlet ...

In this paper the heat transfer characteristics of a two-phase closed thermosyphon over a wide range of heat transfer rates, system pressure, aspect ratios and filling ratios were studied. The experiments focused on the boiling and condensation heat transfer characteristics of a thermosyphon with a copper tube having 25 and 32 mm inside and outside diameters. Distilled water was used as the wor...