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.P., Kubrak, J., 2015. Measurements of Turbulence Structure in a Compound Channel. In: Rowiński, P., Radecki-Pawlik, A. (Eds.): Rivers - Physical, Fluvial and Environmental Processes, GeoPlanet. Earth and Planetary Sciences. Springer International Publishing Switzerland, pp. 229-254. DOI: 10.1007/978-3-319-17719-9_10. Kozioł, A., Urbański, J., Kiczko, A., Krukowski, K., Siwicki, P., 2016. Turbulent intensity and scales of turbulence after hydraulic jump in rectangular channel. Ann. Warsaw Univ. Life Sci. - SGGW, Land Reclam., 48, 2, 99-109. DOI: 10.1515/sggw-2016

References Hoshmandi F., Zahiri A., Dehghani A. A. and Meftah Halghi M., 2014, “Comparison of Estimation of Shear Stress Distribution in Open Channels”, Journal of Soil and Water Protection Research, 21(5), 284-295. I. Nezu, and H. Nakagawa, 1993, “Turbulence in open-channel flows”, Rotterdam, The Netherlands: Balkema. D. W. Knight, J. D. Demetrious, and M. E. Hamed, 1984, “Boundary shear in smooth rectangular channel”, J. Hydraulic Eng., 110(4), 405-422. A. Tominaga, I., Nezu, K. Ezaki, and H. Nakagawa, 1989, “Threedimensional turbulent structure in straight

. Publication 20. ILRI. ISBN 90 70754 15 0. Böhm, P., 2010. Shape of a Free Water Jet Overflowing from a Rectangular Channel. Brno, pp. 61, Brno University of Technology. Faculty of Civil Engineering. Institute of Water Structures. Castro-Orgaz, O., Hager, W.H., 2010. Moment of momentum equation for curvilinear freesurface flow. Journal of Hydraulic Research, 48, 5, 620-631. Castro-Orgaz, O., Hager, W.H., 2011. Vorticity equation for the streamline and the velocity profile. Journal of Hydraulic Research, 49, 6, 775-783. Chow, V.T., 1959. Open-Channel Hydraulics. McGraw

References Ab Ghani, A., Salem, A.M., Abdullah, R., Yahaya, A.S., Zakaria, N.A., 1999. Incipient motion of sediment particles over loose deposited beds in a rigid rectangular channel. Proc. 8th Int. Conf. Urban Storm Drainage, Sydney, Australia. Ab Ghani, A., Zakaria, N.A., Kassim, M., Nasir, B.A., 2001. Sediment size characteristics of urban drains in Malaysian cities. Urban Water J., 2, 335-341. Ab Ghani, A., Azamathulla, H.M., Chang, C.K., Zakaria, N.A., Hasan, Z.A., 2011. Prediction of total bed material load for rivers in Malaysia: A case study of Langat

of the streamlined broad-crested weir. ICE Proc., 38, 657–678. Montes, J.S., Chanson, H., 1998. Characteristics of undular hydraulic jumps: experiments and analysis. J. Hydr. Eng., 121, 2, 192–205. Nikolov, N.A., Minkov, I.N., Dimitrov, D.K., Mincheva, S.K., Mirchev M.A., 1978. Hydraulic calculation of a submerged broad-crested weir. Hydrotechnical Construction, 12, 6, 631–634. Noor Afzal, Bushra, A., Abu Seena, 2011. Analysis of turbulent hydraulic jump over a transitional rough bed of a rectangular channel: universal relations. J. Eng. Mech., 137, 12, 835

References [1] Dittus F.W. and Boelter L.M.K. (1930): Heat transfer in automobile radiator of the tubular type. – University of California at Berkley Publ. Eng., vol.2, pp.443-461. [2] Gamrat G., Faver-Marinet M. and Asendrych D. (2005): Conduction and entrance effects on laminar liquid flow and heat transfer in rectangular micro-channels . – Int. J. Heat and Mass Transfer, vol.48, pp.2943-2954. [3] Ma J., Li L., Huang Y and Liu X. (2011): Experimental studies on single-phase flow and heat transfer in a narrow rectangular channel . – Nuclear Engineering and

Abstract

In this paper we extend previous results on the effective thermal conductivity of liquid helium II in cylindrical channels to rectangular channels with high aspect ratio. The aim is to compare the results in the laminar regime, the turbulent regime and the ballistic regime, all of them obtained within a single mesoscopic formalism of heat transport, with heat flux as an independent variable.

Abstract

This paper presents a theoretical model of the hydroelectromagnetic thruster (electromagnetic three-phase induction seawater pump), which was developed from a semi-space model for an infinity conductor, where the electrically fluid - seawater occupies a semi-space, bordered by an ideally ferromagnetic wall. At the fluid surface, it is found a web of currents having density vector oriented in the direction of Oy axis, and fluid movement - considered a translational motion at constant velocity - is directed along the Ox axis. In this regard, for certain arrangements of three phase windings inductors, were performed calculations in order to estimate the forces, powers and efficiency for electromagnetic three-phase induction pump, having the seawater as induced fluid. Following the analysis of the traction force expression, it was found that it is possible to achieve a hydroelectromagnetic thruster, as a rectangular channel with the specific configuration of the three-phase windings, enabling to develop the electromagnetic traction forces for seawater as fluid induced conductor, forces comparable with propellers systems

A complete three-dimensional and single phase model for proton exchange membrane (PEM) fuel cells was used to investigate the effect of using different channels geometry on the performances, current density and gas concentration. The proposed model was a full cell model, which includes all the parts of the PEM fuel cell, flow channels, gas diffusion electrodes, catalyst layers and the membrane. Coupled transport and electrochemical kinetics equations were solved in a single domain; therefore no interfacial boundary condition was required at the internal boundaries between cell components. This computational fluid dynamics code was employed as the direct problem solver, which was used to simulate the three-dimensional mass, momentum, energy and species transport phenomena as well as the electron- and proton-transfer process taking place in a PEMFC. The results showed that the predicted polarization curves by using this model were in good agreement with the experimental results and a high performance was observed by using circle geometry for the channels of anode and cathode sides. Also, the results showed that the performance of the fuel cell improved when a rectangular channel was used.

Abstract

In the present study, we have developed a code using Matlab software for solving a rectangular aluminum plate having void, notch, at different boundary conditions discretizing a two dimensional (2D) heat conduction equation by the finite difference technique. We have solved a 2D mixed boundary heat conduction problem analytically using Fourier integrals (Deb Nath et al., 2006; 2007; 2007; Deb Nath and Ahmed, 2008; Deb Nath, 2008; Deb Nath and Afsar, 2009; Deb Nath and Ahmed, 2009; 2009; Deb Nath et al., 2010; Deb Nath, 2013) and the same problem is also solved using the present code developed by the finite difference technique (Ahmed et al., 2005; Deb Nath, 2002; Deb Nath et al., 2008; Ahmed and Deb Nath, 2009; Deb Nath et al., 2011; Mohiuddin et al., 2012). To verify the soundness of the present heat conduction code results using the finite difference method, the distribution of temperature at some sections of a 2D heated plate obtained by the analytical method is compared with those of the plate obtained by the present finite difference method. Interpolation technique is used as an example when the boundary of the plate does not pass through the discretized grid points of the plate. Sometimes hot and cold fluids are passed through rectangular channels in industries and many types of technical equipment. The distribution of temperature of plates including notches, slots with different temperature boundary conditions are studied. Transient heat transfer in several pure metallic plates is also studied to find out the required time to reach equilibrium temperature. So, this study will help find design parameters of such structures.