Heat transfer improvement in circular pipe by using nanofluid and twisted tape is presented in this review paper. Experimental and numerical studies are incorporated involving both the range of turbulent and laminar flow. Effect of type and volume fraction of nanofluid on performance of heat transfer was referred along with the length and twist ratio of the tape through the pipe on heat transfe...

The internal rotations around the some within a ylide involving theophylline has been studied using the dynamic 1H NMR spectroscopic technique in different temperatures. The kinetic and activation quantities were calculated. Arrhenius, Eyring and classic methods were applied for isomers. compared for carbon-carbon double, carbon-carbon single bond for Z isomer. The results obtained by classic m...

Climatologies of streamer events derived from a transport model and a coupled chemistry-climate model V. Eyring, M. Dameris, V. Grewe, I. Langbein, and W. Kouker DLR Institut für Physik der Atmosphäre, Oberpfaffenhofen, D-82234 Wessling, Germany Forschungszentrum Karlsruhe, Institut für Meteorologie und Klimaforschung, 76344 Eggenstein-Leopoldshafen, Germany Received: 17 October 2002 – Accepted...

Experimental investigations of heat transfer coefficient of CuO/Water nanofluid are reported in this paper. The heat transfer coefficient of the CuO/water was measured with the help of double pipe heat exchanger. The nanofluid was prepared by dispersing a CuOnano particle in deionized water. CuO/water nanofluid with a nominal diameter of 27nm at different volume concentrations (0.1 &0.3 vol.%) ...

A two-phase flow experiment using air and water-based γ-Al2O3 nanofluid was conducted to observe the basic hydraulic phenomenon of nanofluids. The local two-phase flow parameters were measured with a conductivity double-sensor two-phase void meter. The void fraction, interfacial velocity, interfacial area concentration, and mean bubble diameter were evaluated, and all of those results using the...

This study analyzes the characteristics of alumina (Al2O3)/water nanofluid to determine the feasibility of its application in an air-cooled heat exchanger for heat dissipation for PEMFC or electronic chip cooling. The experimental sample was Al2O3/water nanofluid produced by the direct synthesis method at three different concentrations (0.5, 1.0, and 1.5 wt.%). The experiments in this study mea...

Nanofluids are liquids containing suspensions of solid nanoparticles and have attracted considerable attention because they undergo substantial mass transfer and have many potential applications in energy technologies. Most studies on nanofluids have used low-ionic-strength solutions, such as water and ethanol. However, very few studies have used high-ionic-strength solutions because the aggreg...

This article mainly concerns theoretical research on entropy generation influences due to heat transfer and flow in nanofluid suspensions. A conventional nanofluid of alumina-water (Al2O3-H2O) was considered as the fluid model. Due to the sensitivity of entropy to duct diameter, miniand microchannels with diameters of 3 mm and 0.05 mm were considered, and a laminar flow regime was assumed. The ...

It is necessary to control the temperature of solar cells for enhancing efficiency with increasing concentrations of multiple photovoltaic systems. A heterogeneous two-phase model was established after considering the interacting between temperature, viscosity, the flow of nanofluid, and the motion of nanoparticles in the nanofluid, in order to study the microchannel heat sink (MCHS) using Al2O...

Numerical simulation and experimental investigation were used for study of laminar forced convective heat transfer of Al2O3/water nanofluid. Single phase model with temperaturedependent properties was employed for numerical simulation of transport phenomena in nanofluid. The results of experiments and computer-aided simulation indicated remarkable enhancement of convective heat transfer of base...