Influence of train speed on the loss of fine coals due to blow-out

The article focuses on the consideration of the issue of ensuring the safety of fine coals transported on open-top rolling stock in the matter of minimizing their losses due to blow-out. An aerodynamic model of the coal blow-out process during its transportation by open-top cars was created and studied in specialized software in the field of fluid dynamics research (CFD), which provided an opportunity to numerically estimate the size of coal losses from blow-out using data on the aerodynamic parameters of air flows flowing around the cargo surface. The study of the influence of train speed on the size of losses of fine coals from blowing was carried out by modeling the blowing process with varying train speeds from 20 to 140 km/h, which also allowed us to establish the speed of the beginning of the intensive blowing-out of small cargo particles - 40 km/h. This speed value is consistent with that obtained by scientists from the Siberian Transport University during mass experimental transportation of bulk cargo in the 60-70s of the last century, which indicates the adequacy of the results obtained during the modeling of the blowing process. The results of the study made it possible to estimate numerical dependences of the size of losses of coal fine particles due to blow-out from changes in train speed, which is important to consider when choosing coal-dust mitigation measures to reduce the size of losses from blow-out. Further refinement of the obtained dependencies for other fine-grained bulk cargo seems possible using the developed aerodynamic model of the blowing process, both by specifying the value of the critical blowing speed of an individual bulk cargo, and also due to the formation of the corresponding shape of the cargo surface, characteristic of a certain loading method and the parameters of the open-top car model, which affect the loading height, is an equally important factor determining the size of losses from blowing.