in this study, fluid flow and energy separation in a micro-scale ranque-hilschvortex tube are numerically investigated. the flow is assumed as 2d, steady,compressible ideal gas, and shear-stress-transport sst k-w is found to be a bestchoice for modeling of turbulence phenomena. the results are in a good agreementwith the experimental results reported in the literature. the results show that flu...

this paper modeled heating air of a room through examining free convection in a 3d chamber. the chamber had cold and hot sources with tc and th temperatures, respectively. its other walls were adiabatic. this study aimed at predicting effect of temperature difference, displacement of hot and cold sources and their aspect ratio on flow field, temperature and heat transfer rate. to conduct the st...

In this study, the behavior of nanoparticles using a numerical model is discussed. For this study a model for the expansion in free convection heat transfer and mix in a rectangular container with dimensions of 1 × 4 cm using Nano-aerosols in the air is going when copper nanoparticles, use and by changing the temperature difference between hot and cold wall, we will examine its impact on the ra...

Abstract—Closed die forging is a very complex process, and measurement of actual forces for real material is difficult and time consuming. Hence, the modelling technique has taken the advantage of carrying out the experimentation with the proper model material which needs lesser forces and relatively low temperature. The results of experiments on the model material then may be correlated with t...

This paper modeled heating air of a room through examining free convection in a 3D chamber. The chamber had cold and hot sources with Tc and Th temperatures, respectively. Its other walls were adiabatic. This study aimed at predicting effect of temperature difference, displacement of hot and cold sources and their aspect ratio on flow field, temperature and heat transfer rate. To conduct the st...

Results The temperature of the hindlimb decreased rapidly with cold exposure in all cases, and minimum tissue temperature was observed one minute after cold exposure in both groups. The reduction in tissue temperature was lager in female than in male (female: 23.0+/-6.1 degree C vs. male: 12.0+/-6.1 degree C) (p<0.05). This difference was significantly existed until 14 minutes after cold exposu...

A heat pipe exchanger was adopted to recover the engine exhaust energy and its internal gas pressure. Velocity and temperature distribution were obtained with the computational fluid dynamics software called ‘FLUENT’. Based on the simulation results, the structure of the exchanger was improved, and its working performance was verified by experiments. The experiments showed that the pressure los...

a brass vortex tube (vt) with interchangeable parts is used to determine the optimum cold end orifice diameter, main tube length and diameter. experiments were carried out to study the effects of operating pressure as well. it is shown that there is an optimum value for cold end orifice diameter, which is equal to 4mm and there is an optimum value for cold and hot exit temperature difference at...

in urban areas the world over the past several decades was associated with an exponential growth of population, which led to widespread changes in land use urban and land cover. therefore, in this study, the daily temperature data from 1951 to 2010 at the synoptic station shiraz 60-year period were reviewed. then the average daily temperature average was five days into quintile. results of clus...