Examination RUSSIAN TRANSPORT UNIVERSITY (MIIT) V-3

Task 2.1
Determine the lifting force of a balloon filled with hydrogen if its volume on the surface of the earth is V at a pressure of 750 mm Hg. Art. and temperature t.

Task 2.2
The gas mixture consists of hydrogen and air. Mass fraction of hydrogen is equal to mH2. Determine the gas constant of the mixture and its specific volume under normal conditions.

Task 2.3
A closed vessel with a capacity of V = 0.5 m3 contains air at a pressure p1 and a temperature t1. As a result of cooling the vessel, the air contained in it loses Q = 100 kJ. Taking the heat capacity of the air constant, determine what pressure p2 and temperature t2 are then set in the vessel.

Task 2.4
The compressor draws in 100 m3 / h of air at a pressure of p1. The final air pressure is p2. Determine the engine power in kW for the compressor drive during isothermal compression.

Task 2.5
Oxygen from a vessel with a constant pressure p1 bar and temperature t1 flows into the atmosphere through a tube with an internal diameter of 15 mm. External pressure p2 = 1 bar. The gas outflow process is adiabatic. Determine the rate of air flow and its second flow rate.