there are different methods to reduce drag in high speed hulls. one of these methods is a change in the shape of the body by adding longitudinal side tunnels. in this paper it has been attempted to determine the influence of the tunnel height on hydrodynamic characteristics of the hull to achieving an optimum shape for the tunnel. to achieve this purpose, numerical simulation of the problem has...

high speed trains are an indispensable part of rapid transportation systems in many countries. as the fastest means of transport on the ground, these trains are extremely sensitive to the terrain and track conditions. geometrical irregularities and mechanical characteristics of the track, together with inconsistencies in the lane (including bridges that support the track) are considered importa...

Union Internationale des Chemins (UIC) defines the high-speed railway (HSR) as a system that contains infrastructure and rolling stock. The can be newly built dedicated lines enabled for trains to travel with speed above 250 km/h or upgraded conventional up 200 even 220 km/h. HSR requires specially increased power weight ratio must have an in-cab signalling traditional systems are incapable of