We study a multidimensional hyperbolic quasi-gasdynamic (HQGD) system of equations containing terms with a regularizing parameter $\tau>0$ and 2nd order space and time derivatives; the body force is taken into account. We transform it to the form close to the compressible Navier-Stokes system of equations. Then we derive the entropy balance equation and show that the entropy production is like for the latter system plus a term of the order $O(\tau^2)$. We analyze an equation for the total entropy as well. We also show that the corresponding residuals in the HQGD equations with respect to the compressible Navier-Stokes ones are of the order $O(\tau^2)$ too. Finally we treat the simplified barotropic HQGD system of equations with the general state equation and the stationary potential body force and obtain the corresponding results for it.
The problem mentioned in the title is studied.
Рассчитан термодинамический потенциал сверхпроводящего квантового цилиндра. Изучена зависимость критической температуры и теплоемкости сверхпроводящей системы от концентрации электронов и радиуса нанотрубки.
We consider the relations between thermodynamics on the one hand and the (max,+)-algebra and tropical mathematics on the other hand. The contribution of Grigorii Litvinov to tropical geometry is emphasized. Relations for a liquid in the negative pressure domain are given.