Non-Newtonian compressible fluids with stochastic right hand side
Pavel Ludvík, Václav Mácha
TL;DR
The paper addresses the existence of solution concepts for compressible barotropic flows of shear-rate dependent non-Newtonian fluids, where classical weak solutions are obstructed by nonlinear elliptic terms. It introduces measure-valued solutions constructed via Young measures and proves an abstract existence theorem in a very general setting. The framework is extended to accommodate stochastic right-hand side forcing, outlining how randomness is integrated within the measure-valued formulation and the corresponding proof strategy. The results provide a rigorous, broadly applicable basis for analyzing complex, stochastic non-Newtonian compressible flows within a generalized Navier–Stokes model, with implications for continuum mechanics and mathematical fluid dynamics.
Abstract
Fluids with shear-rate-dependent viscosity form a special class of non-Newtonian fluids that play a crucial role in continuum dynamics. We consider a compressible barotropic flow of such fluids, governed by a generalized Navier-Stokes system. Due to the nonlinearity in the elliptic term, obtaining the existence of a weak solutions is challenging. To address this, we introduce the concept of a measure-valued solution, whose existence is established in a very general setting using an abstract theorem on the existence of a Young measure. We also discuss the proof of this key result.
