eng
Maršík, František
Trávníček, Zdeněk
Antošová, Zuzana
Souvislost mezi principem nejmenší akce a termodynamickou podmínkou stability
The connection between the principle of the least action and the thermodynamic condition of stability
principle of the least action
thermodynamic stability condition
annular swirl flow
https://www.engmech.cz/improc/2023/159.pdf
https://hdl.handle.net/11104/0344245
http://www.nusl.cz/ntk/nusl-532607
The extended principle is formulated for a material point (M.P.) X, which has nonzero mass, temperature, and trajectory x(X,t). The Lagrangian of this variation principle is equal to the kinetic energy from which, the internal energy of the material point (which depends on the entropy) and the additional energy caused by the frictional force are subtracted. The relation between the inertial force and the entropy gradient is found and the gravitational force is completely replaced by the entropy gradient. Thanks to the mentioned properties of the total enthalpy, the Thermodynamic criterion of stability of the state of M.P., is formulated.
2023