Tread braking of railway wheels – temperatures generated by a metro train

Abstract

Tread braking of railway wheels results in the kinetic energy of the train being dissipated into the wheel and blocks in the form of heat. This heat is further conducted into adjacent structures, notably the cold rail, and also transferred into the surroundings by convection and radiation. Heat partitioning between wheel and block is, for short time periods, controlled by local thermal interactions at the contact point and by the conductive properties of the bodies. However, for a metro train that performs longer periods of intermittent braking (or for drag braking) convective and radiation cooling properties of the components come into play. In the present study, results from brake rig tests and from in-field testing of a metro train are presented and used to calibrate a simulation model. It is found that the cooling level of the wheels of the metro train is substantially lower than for the wheels of a freight wagon. Moreover, it is found that the first axle on the metro train is exposed to higher cooling levels than the remaining axles. In a numerical example, temperatures of tread braked wheels are calculated using the new findings for a metro train, and the results obtained are compared with wheel temperatures as calculated assuming freight wagon conditions.

Thermal capacity of tread-braked railway wheels. Part 2: Applications

“…Case S13 has more convection cooling, see the previous study, 9 and 17% higher lateral loading (corresponding to a guiding wheelset) than Case S1 (non-guiding wheelset). It is found that the maximum tread temperature decreases from about 340℃ in Case S1 to 280℃ in Case S13.…”

Frictional Heating in Railway Brakes: A Review of Numerical Models

“…The two-dimensional, axisymmetric model presented by Vernersson [50] was calibrated by Teimourimanesh et al with the experimental data in [44] and used to calculate the temperature evolution in the course of metro route profile simulation [45]. The numerical analysis comprised 30 stop brake applications each followed by a short cooling period and a phase to cool down the friction pair to ambient temperature.…”

Thermal capacity of tread-braked railway wheels. Part 1: Modelling

“…The thermal model is introduced and described in detail in Vernersson 17 and was calibrated for freight applications in Vernersson. 12 It was calibrated for a metro application in Teimourimanesh et al., 18 and this is the thermal model used in the present work. A short review is given here.…”

“…The reason is for assessing a non-guiding wheelset is that these wheelsets have a lower cooling than the guiding wheelset and thus higher temperatures are obtained; see Teimourimanesh et al. 18 The maximum axle load prescribed for this typical metro wheel is 16 tonnes. Resulting stress ranges on the flange and field sides of the web are illustrated in Figure 13.…”