In this study, the thermal characteristics of turbulent nanofluid flow in a helical tube in the tube heat exchanger (HTTHE) were assessed numerically through computational fluid dynamics (CFD) simulation. The findings of both the turbulent models: realizable k-epsion (k-ε) and re-normalisation group (RNG) k-epsilon were compared. The temperature distribution contours show that realizable and RN...

The heat transfer for a non-Newtonian power-law fluid over a moving surface is investigated by applying a uniform suction/injection velocity profile. The flow is influenced by internal heat generation/absorption. The energy equation is solved at constant surface temperature condition. The Merk-Chao series is applied to obtain a set of ODEs instead of a complicated PDE. The converted ordinary diffe...

accumulative roll bonding (arb) was used to fabricate the cu-zn multilayer and cu-zn solid solution. a lamellar structure with the hardness of about 130 vhn was formed after eight arb cycles. following to the suitable heat treatment, a solid solution with a uniform microstructure and hardness of about 57 vhn was produced. the dominant wear mechanism in the arb processed multilayer was found to ...

Abstract   An empirical investigation was carried out to study convective heat transfer of nanofluid flow inside an inclined copper tube under uniform heat flux condition. Required data are acquired for laminar and hydrodynamically fully developed flow inside round tube. The stable CuO-base oil nanofluid with different nanoparticle weight fractions of 0.5%, 1% and 2% was produced by means of ul...

this paper presents a three-dimensional numerical investigation carried out in turbulent forced convection in a tube with helical ribs. enhancement of heat transfer using helically corrugated tubes has beenstudied experimentally by many researchers but there exist a few published numerical analyses results. the paper also introduces the results of heat transfer and friction factor data for inco...

Conjugate heat transfer problem of a disc winding in a power transformer is studied using commercial CFD software. The study is done for oil flow, temperature distribution, hot spot location and temperature of the winding, for three different cases: first, no oil leakage past the top washer; second, partial leakage due to a 2 mm gap between the top oil guiding washer and cylindrical pressboard;...

13 A thermal model for the human body is used to assess the temperature of the body and 14 a person’s thermal comfort level. Most models available in the literature were 15 developed for a uniform thermal environment and have limited applications. This study 16 developed a 12-segment model for transient and non-uniform surrounding conditions 17 by considering two-dimensional heat transfer in ea...

Microscale fluid dynamics has received intensive interest due to the emergence of microelectromechanical systems technology. When the mean free path of the gas is comparable to the channel’s characteristic dimension, the continuum assumption is no longer valid and velocity slip and temperature jump may occur at the duct walls. Slip flow heat transfer in annular microchannels has been examined. ...

During cross flow in a heat exchanger, heat transfer in the front portion of the tube is more compared to back portion of the tube. This is due to less formation of vortices at the backside of the tube. For uniform heat transfer to take place throughout the tube, it is necessary to increase the vortex formation at the rear side of the tube. The aim of this study is to explore the possibilities ...

fatigue behavior of a vanadium microalloy steel has been studied in this research. here, microstructure constituents were considered which essentially are dependent on the heat treatment conditions. the results of high cycle fatigue tests revealed that heat treatment procedure and cooling rates have significant effects on fatigue properties. optimal heat treatment cycle of the microalloyed stee...