In this study a polypropylene material with talcum reinforcement used for sewer pipes has been subjected to an annealing procedure at 80°C, roughly 60°C above the actual application temperature, in air for a time period of 18 months. As expected, examination of the material showed no significant decrease in mechanical or fracture mechanical properties due to the temperature exposure. However, s...

On-line spray water cooling (OSWC) of electric-resistance-welded (ERW) steel pipes can replace the conventional off-line heat treatment process and become an important and critical procedure. The OSWC process improves production efficiency, decreases costs, and enhances the mechanical properties of ERW steel pipe, especially the impact properties of the weld joint. In this paper, an annular OSW...

Isothermal journal bearings have been developed by incorporating heat-pipe cooling. The heat pipe assists in spreading heat rapidly along the bearing circumference, resulting in a very small temperature gradient, low peak temperature, and stable transient thermal behavior. This paper presents a model for the isothermal journal bearings and the results of analyses. The heat pipe in the isotherma...

The direct numerical simulation (DNS) of heat transfer in a fully developed turbulent pipe flow with for various Prandtle numbers are performed to obtain statistical quantities such as turbulent heat flux, and temperature variance. Main emphasis is placed on Prandtl number effects on turbulent heat transfer in pipe flow. Probability density functions and joint probability density functions of v...

In this study, in order to increase the heat transfer rate in concentric double-pipe heat exchangers by an active method, a rotating ball valve was mounted downstream of the outer pipe end and used as a pulse generator. In the experimental set-up, hot water (40-70 °C) was passed through the inner pipe with fixed mass flow rate (Reynolds number ≈ 10,200) while cold water was passed through the a...

The ground thermal properties and the heat-transfer efficiency of the borehole heat exchanger (BHE) system are key parameters for designing ground-coupled systems. Proper design of such systems requires good knowledge of these parameters, providing an efficient and economic operation. For this purpose a test procedure known as Thermal Response Test (TRT) was developed in 1996 at the Oklahoma St...

This paper reported an experimental research of steady-state heat transfer behaviour of a gas flowing through a fixed bed under the different operating conditions. Studies had been carried out in a fixed-bed packed methanol synthesis catalyst percolated by air at appropriate flow rate. Both radial and axial direction temperature distribution had been investigated under the different operating c...

in this work, the characteristics of flow and heat transfer of a fluid containing nano particles of aluminum oxide with the water volume fraction (0.1-0.2-0.3)(v/v) percent of the reports. the overall heat transfer coefficient, heat transfer and the average heat transfer fluid containing nano water - aluminum oxide in a horizontal double pipe counter flow heat exchanger under turbulent flow con...

The solar gravity heat pipe has been widely used for solar thermal water heating because of its high efficient heat transfer and thermal diode characteristics. Operated on fluctuant and low intensity solar radiation conditions, a solar gravity heat pipe may frequently start up. This severely affects its solar collection performance. To enhance the thermal performance of the solar gravity heat p...

The adsorption performances of compound adsorbent (the mixing of activated carbon and CaCl2 by proper technology)-ammonia are studied, which shows the obviously improvement for long term stable operation of adsorption/desorption, and also the large adsorption cooling density. A multifunction heat pipe for heat transfer design in adsorber is invented to use waste heat for heating and sea water f...