Quantification of the aerodynamic gain on two virtually coupled modular trains

Abstract

To make railway systems more autonomous and energy efficient, the suction phenomenon induced by virtual coupling (VC) can be considered as a beneficial source of energy saving since trains are very closely spaced. A minimum safe distance between railway systems must be defined and maintained to ensure the safety of the whole convoy. The purpose of this paper is to study and quantify the aerodynamic gain in case of VC of two modular and autonomous trains 'Smart Cabins' as designated in our project. Computational fluid dynamics simulations are investigated to analyze the aerodynamic effect under several scenarios by varying the inter-cabins distance. Some design simplifications have been made for each Smart Cabin to prepare simulations and reduce computation time. Simulation results confirm the interest of VC in the sense of reducing coefficient drag of the full convoy up to 27%, which reflects a power gain of about 4% of the total traction power required for a single Smart Cabin (~200 kW).

Virtual Coupling in Railways: A Comprehensive Review

“…Figure 14 shows the basic idea of this control method. Reference [81] performed CFD simulations to analyze the aerodynamic effect in different scenarios and found that VC reduced the drag coefficient of the entire convoy by up to 27%, corresponding to a power gain of approximately 4% of the total traction power required for a single smart cabin (~200 kW).…”

Railway Virtual Coupling: A Survey of Emerging Control Techniques

“…VC can significantly reduce train operation headways [16] to increase line capacity [17]. VC can also help to reduce energy costs under specific specialized cases [18]. Market potential studies [19] have indicated that VC train operations can be very attractive to customers of various rail transport sectors including high-speed, main-line and regional with benefits that are especially relevant for freight trains.…”