Construction of a mathematical model of the process gas outflow through small body opening boiler railroad tank cars

The paper describes a mathematical model of gas-dynamic movement through the through defects in the body of the boiler tank cars. The mathematical model allows to take into account the processes of gas flow at low pressure drop and the impact of the level of roughness of the inner surface of the through channel formation jet escaping gas. The comparison of the results of theoretical modeling and experimental studies of the velocity of the gas flow and temperature under different conditions. The study identified the laws of gas flow through a series of classic models through defects. Shows the dependence of the temperature of the escaping gas flow from the exhaust velocity and the level of roughness of the internal surface of the through channel, which allows us to estimate the nature of gas flow and temperature gradient. The obtained results allow to adjust the level of sensitivity to rejection temperature during thermal leakage control boilers railway tanks.