Modification of train resistance formulae for container trains based on operational run-down tests

Abstract

The method currently used for the estimation of train resistance based on specific train resistance has some shortcomings. This method is applied by various railway infrastructure managers, e.g. in the Czech Republic. In this article, first, the Czech formulae for the calculation of train resistance of freight trains are introduced and compared with selected foreign methods. Operational experience from recent years shows that the train resistance formulae used are too conservative and do not correspond to the state-of-the-art railway technology. Therefore, a modified approach for the estimation of train resistance is proposed in this paper. The modification is based on an analysis of run-down tests conducted with ordinary container trains currently operating on the Central European railway network. The contributing factors in the proposed train resistance formula are discussed.

A Literature Review on Train Motion Model Calibration

“…For instance, they require less resources, benefit from a larger amount of data available and may lead to estimates that represent the current operating conditions more faithfully. Furthermore, test runs may not be possible for trains of variable composition, thus model calibration based on operational data may be crucial for such railway systems [43]. The archetypical example are freight wagons, since flat, open and closed wagons show radically different dynamics.…”

“…This is supported by [58], where the impact of bogie fairings on the running resistance is evaluated, observing that they may reduce up to 10% of the total aerodynamic drag, including some impact on r 0 . In [43], new running resistance formulas are estimated with the aim to update the phenomenological formulas used in the Czech Republic. The existing methodological formulas are found to be too conservative, being most of them not correct physically.…”

Train motion model calibration: research agenda and practical recommendations

“…Moreover, the estimates obtained from scale tests in wind tunnels require a scale correction. Particularly, freight trains of variable rolling stock composition and geometry benefit from operational data-based parameter estimation, where tests and CFD model calibration are not available [13].…”

A multivariate nonlinear regression model for the resistance power of a light rail vehicle

“…The fourth and ultimate model is summation of third model and a model which depends on r as shown in Equation (21).…”

“…Spinalbese expressed running resistance as a multiplication of mass and second degree polynomial function of speed of a train to use in CFD analysis for aerodynamic resistances [20]. Michalek expressed train resistance with multiplication of the weight of the train and a second degree polynomial of speed for a container train [21]. Kwon modelled resistance of high speed train with second degree polynomial of speed, where the coefficients of the polynomial depends on mass of train, dimensionless parameter related to type of rolling stock, front surface cross section area, parameter for shape of the train, parameter for condition of the surface and partial perimeter of the rolling stock down to rail level [22].…”