A Weighted Regularity Criterion for Suitable Weak Solutions of Incompressible Non-Newtonian Fluids
Jae-Myoung Kim
TL;DR
This work studies regularity for a 3D incompressible non-Newtonian fluid with power-law stress $S(Du)=(\mu_0+\mu_1|Du|^{q-2})Du$ in $\mathbb{R}^3$ and develops a weighted regularity criterion based on the weighted gradient of the velocity and leverages the Caffarelli–Kohn–Nirenberg and Stein inequalities to obtain weighted a priori bounds. An $\varepsilon$-regularity framework for suitable weak solutions is established, leading to semi-regularity under finite weighted norms and appropriate initial data. The results extend existing weighted criteria for shear-thinning flows to the non-Newtonian setting and clarify how spatial weights govern regularity, with implications for singularity formation.
Abstract
It establishes a regularity criterion for non-Newtonian fluids in $\mathbb{R}^3$ in terms of the weighted gradient of the velocity field, based on the Caffarelli--Kohn--Nirenberg inequality.
