COMPARATIVE WIND INFLUENCE ON USE PHASE ENERGY CONSUMPTIONS OF ROADS AND RAILWAYS
Last modified: 2017-02-28
Even if transportations systems could partly rely on renewable energies, their optimization should involve energy and mobility criteria. In this study, surrounding wind fields and traveling speed are conjointly investigated in order to evaluated achievable reductions in fuel consumptions for both railways and road transportation systems.
In the first part of this work, aerodynamic forces on trains are evaluated with the help of an energy model, validated with experimental tests data. For that, numerical determination of aerodynamic coefficients for several wind and topological situations have been computed with Solid-Works and associated to atmospheric characteristics determined over the considered high-speed line (Rhine-Rhone line ; about 140 km) with the AROME model (meteo-france), from measurements at several weather stations.
Simulation results show that for a weak wind and a train traveling at high speed, wind influence is about 5% on aerodynamic forces power. However, for a moderate train speed (about 45 m/s), a slightly stronger wind (about 5 m/s) has an influence of about 30%, compared to the without wind case.
In a second time, road experiments have been conducted with a passenger car equipped with an air flow meter and an oil flow meter, in addition of dynamical measurements as speed, position, altitude... Similarly to the railway case, wind exposition could be considered as a significant road design parameter.
In conclusion, this work based on large sets of full-scale experimental data and the numerical simulation of the aerodynamic forces, points out that wind influence on total aerodynamic power consumption is noticeable, both for railways or road transportation systems.