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On the proper interpretation of nanofluid convective heat transfer

Technological developments of the last decades allow the production and the dispersion of particles of sizes ranging between 10 and 100 nm in liquids. In a large number of recent studies the resulting nanofluids have been reported to display anomalously high increase in convective heat transfer. The present study compiles experiments from five independent research teams investigating convective he

Simulation of heat transfer in the contact line region of pure pentane and pentane/hexane mixture in a closed microcavity

Understanding the heat transfer characteristics in the three-phase contact line region has great significance in achieving efficient evaporation/condensation. Phase change becomes especially complicated when a fluid mixture is used. The dynamics of phase change heat and mass transfer in the three-phase contact line region of binary fluid is still not clear. Based on the volume of fluid (VOF) model

Pressure fluctuations of liquid-liquid slug flow in cross-junction square microchannels

Microchannels are widely used for heat transfer enhancement. The pressure characteristics are one of the most important factors affecting the heat transfer performance, and the pressure regulation may also control the heat transfer precisely in turn. As a common flow pattern of two-phase flow, slug flow has obvious advantages for heat and mass transfer, like steady flow rate and large interface ar

Investigation of heat transfer and fluid flow in fractal truncated ribbed channels for the internal cooling of turbine blades

Ribs are widely employed in internal cooling passages of turbine blades to enhance heat transfer. From the mathematics, a fractal is an abstract object used to describe naturally occurring objects which exhibits similar properties with increased smaller scales. In a ribbed channel, originating from two sides truncated ribs, fractal truncated ribs are built and the evolving process contains three s

Experimental investigation of heat transfer enhancement on the endwall around an obstacle embedded with a vortex generator pair

Heat transfer enhancement on the endwall around an obstacle embedded with a pair of vortex generators is investigated. Obstacles with cylindrical and square cross sections are experimentally examined and compared with and without vortex generators. The vortex generators employed is a pair of longitudinal winglet vortex generator. Local Nusselt numbers are calculated for both types of obstacles in

Enhancement of HFE-7200 pool boiling heat transfer on copper surfaces with nanoparticle coatings

Saturated pool boiling heat transfer of HFE-7200 is investigated experimentally on copper surfaces with nanoparticle coatings at atmospheric pressure. The coatings are generated by an electrophoretic deposition method. Two modified surfaces are prepared with Cu-Zinc nanoparticles of 0.3 mg and 0.6 mg, respectively. During the deposition, ethanol works as the solvent while the electrical potential

A statistical method for parameter estimation from Schroeder decay curves

The sound decay curve, measured by either the interrupted noise method or the Schroeder method, can provide relevant information pertaining to a room’s acoustical properties. However, the relevant information is not always readily extractable from the measurements. In this study, measurements of the decay curves of the historically important Vadstena Abbey church in Sweden have been obtained using

Pygmy resonances: what's in a name?

The centroid, width and percentage of energy weighted sum rule of dipole resonances can be strongly affected by dynamical fluctuations and static deformations of the nuclear surface, deformations and fluctuations which, in turn, depend on pairing, and thus on Cooper pairs. Because of angular momentum conservation, such insight is restricted, to lowest order, to fluctuations/deformations of quadrup

Modelling tool life in high speed machining of AD730

AD730® is a new type of nickel-based superalloy, developed by Aubert & Duval, with high temperature properties exceeding conventional superalloys such as Alloy 718. This paper presents the tool life model for this superalloy for the purpose of process optimization and manufacturing cost estimation. The tool life modelling is based on comprehensive machining tests, using the Colding model. The

Beyond Ethnographic Representation

This chapter deals with ways in which digital technologies can be utilized to work with moving media in hybrid ways. It will resonate with practices of ethnographic film, but it will also attempt to move beyond traditional, representational notions of this practice, very much in line with the ideas of the “new world of ethnographic film and video” that Phillip Vannini outlines in the introduction