Research in convective heat transfer using suspensions of nanometer-sized solid particles in base liquids started only over the past decade. Recent investigations on nanofluid, as such suspensions are often called, indicate that the suspended nanoparticles remarkably change the transport properties and heat transfer characteristics of the suspension. Bending walls can also improve heat transfer...

This paper presents results of investigations on the application of CuO-water nanofluids for intensification of convective heat transfer. Performance of nanofluids with 2.2 and 4.0 vol.% CuO NPs (nanoparticles) content were examined with regard to heat transfer coefficient and pressure losses in case of turbulent flow in a tube. Negligible impact of examined nanofluid on heat transfer improveme...

Numerical analysis is performed to investigate transport phenomena in channel flows under uniform heating from both side-walls. Emphasis is placed on an effect of heat flux ratio from both sides on the velocity and thermal fields. The twoequation heat-transfer model is employed to determine thermal eddy diffusivity. It is found that (i) under strong heating from both walls, laminarization, i.e....

Research in convective heat transfer using suspensions of nanometer-sized solid particles in base liquids started only over the past decade. Recent investigations on nanofluid, as such suspensions are often called, indicate that the suspended nanoparticles remarkably change the transport properties and heat transfer characteristics of the suspension. Bending walls can also improve heat transfer...

We performed large eddy simulations (LES) of the turbulent natural convection of an electrically conductive fluid (water with 7% Na2SO4 electrolyte solution) in a moderate (4:4:1) aspect ratio enclosure heated from below and cooled from above and subjected to external nonuniformly distributed electromagnetic fields. Different configurations with permanent magnets (located under the lower therma...

The main objective of this paper is to propose a new friction compensation mechanism applied to robotic actuators. Friction is a phenomenon that changes with time and with actuator’s operational conditions. To deal with these parameters variations, it is proposed a neuro-fuzzy algorithm for friction identification and compensation. A Neural Network (NN) was trained off line. The NN output (comp...

REFERENCES 4. S. M. Yih and C. H. Chen, Heat transfer in the thermal entrance region of a turbulent falling liquid film underV. N. Murthy and P. K. Sarma, Heat transfer to nongoing heating or evaporation, Proc. 7th Int. Heat TransNewtonian laminar falling liquid films with smooth wave fir Conference, Munich, Vol. 3, pp. 125-130 (1982). free gas-liquid interface, Int. J. Multiphase Flow 4, 4135....

Turbulent forced convective mass (heat) transfer downstream of blockages with round and elongated holes in a rectangular channel was studied. The blockages and the channel had the same 12:1 (width-to-height ratio) cross section, and a distance equal to twice the channel height separated consecutive blockages. The diameter of the holes was either 0.5 or 0.75 of the height of the channel. Naphtha...

The present work deals with the results of the experimental investigations carried out on augmentation of turbulent flow heat transfer in a horizontal tube by the means of tube inserts, with air as working fluid. Experiments were carried out initially for the plain tube. Nusselt number and friction factor obtained experimentally were validated against those obtained from theoretical correlation...

Numerical simulations of hydrodynamic and thermally fully developed turbulent flow are presented for flow through a stationary duct with periodic array of inline transverse rib turbulators. The rib height to hydraulic diameter ratio e/Dh is 0.1 and the rib pitch to rib height ratio P/e is 10. The effect of secondary flow due to presence of rib turbulators on heat and mass transfer has been inve...