2017

Authors E. Martino, G. Koilias, M. Athanasiou, A. Katsaounis, Y. Dimakopoulos, J. Tsamopoulos, C.G. Vayenas Abstract The triode operation of humidified PEM fuel cells has been investigated both with pure H2 and with CO poisoned H2 feed over commercial Vulcan supported Pt(30%)-Ru(15%) anodes. It was found that triode operation, which […]

Authors D.Fraggedakis, J.Papaioannou, Y.Dimakopoulos, J.Tsamopoulos Abstract A new boundary-fitted technique to describe free surface and moving boundary problems is presented. We have extended the 2D elliptic grid generator developed by Dimakopoulos and Tsamopoulos (2003) [19] and further advanced by Chatzidai et al. (2009) [18] to 3D geometries. The set of […]

Authors A. Syrakos, S. Varchanis, Y. Dimakopoulos, A. Goulas, J. Tsamopoulos Abstract The divergence theorem (or Green-Gauss) gradient scheme is among the most popular methodsfor discretising the gradient operator in second-order accurate finite volume methods, with a longhistory of successful application on structured grids. This together with the ease of […]

Authors D.Pettas, G.Karapetsas, Y.Dimakopoulos, J.Tsamopoulos Abstract Liquid film flow along an inclined plane featuring a slit, normal to the main directionof flow, creates a second gas–liquid interface connecting the two side walls of theslit. This inner interface forms two three-phase contact lines and supports a widelyvarying amount of liquid under […]

Authors Evan Mitsoulis, John Tsamopoulos Abstract Viscoplasticity is characterized by a yield stress, below which the materials will not deform and above which they will deform and flow according to different constitutive relations. Viscoplastic models include the Bingham plastic, the Herschel-Bulkley model and the Casson model. All of these ideal […]