Thermodynamic analysis of changes the internal energy of an ideal gas under adiabatic throttling

The analysis of the irreversible process of adiabatic throttling of an incompressible liquid using the construction of physical and mathematical models of the process is carried out. The nature of irreversible dissipation of mechanical energy in the fluid flow is revealed. An analytical expression is obtained for the always positive so-called specific heat of friction, the value of which depends on the nature of the flow. This value can be equal to zero only in the case of a vortex-free or helical movement. Therefore, only with such movements, the mechanical energy of the flow does not dissipate.