Sometimes the need for non-circular ducts arises in many heat transfer applications because of lower pressure drop of non-circular cross section such as square duct compared to circular tube, particularly in compact heat. But square cross section has poor heat transfer performance and it is expected that using a nanofluid as a new heat transfer media may improve the heat transfer performance of...

The thermal diffusion factors observed for these systems vary considerably with concentration, and frequently show a change in sign at some concentration. New data on ethanol-toluene mixtures show that the sign and magnitude of the separation of the components in a thermal gradient are also strongly dependent on the mean temperature of the system. These observations, together with earlier ones ...

the air temperature trend has been increasing during recent decades, especially in the regions such as iran which is located in dry and semi-dry world belt. in this research we used markov chain to obtain probabilities of heat waves with different continues in kerman province using 20 years daily maximum air temperature data during 1986-2005. we analyzed daily maximum air temperature data of 5 ...

Cross-corrugated triangular channels increase heat transfer in heat exchangers. The mixing effect increases the heat transfer coefficient at the surfaces. In this study, the fluid flow and heat transfer in a triangular corrugated channel are modeled under two constant heat fluxes and different Reynolds numbers. In order to validate, k-ω turbulence model is used. Also, the effect of magnetic fie...

In the design of heat exchangers, it is necessary to determine the heat transfer rate between hot and cold fluids in order to calculate the overall heat transfer coefficient and the heat exchanger efficiency. Heat transfer rate can be determined by inverse methods. In this study, the unknown space-time dependent heat flux imposed on the wall of a heat exchanger internal tube is estimated by app...