Abstract:
A new solution to the Cauchy problem for a nonstationary quasi-hydrodynamic system is constructed. It does not satisfy either the Navier-Stokes equations or the Euler equations. Using Lin's substitution, the quasi-hydrodynamic system was reduced to three partial differential equations. Three Cauchy problems were posed and solved for the indicated equations. These three solutions generate a new solution to the Cauchy problem for a quasi-hydrodynamic system.
At $c_s\to +\infty$, where $c_s$ is the sound velocity in the fluid, it turns into the solution of the Cauchy problem for the corresponding Navier-Stokes system.