TY - JOUR AU - Zhan, Huashui AU - Zhi, Yuan AU - Niu, Xiaohua PY - 2022 TI - On a non-Newtonian fluid type equation with variable diffusion coefficient JO - AIMS Mathematics SP - 17747 EP - 17766 VL - 7 IS - 10 AB - Since the non-Newtonian fluid type equations arise from a broad and in-depth background, many research achievements have been gained from 1980s. Different from the usual non-Newtonian fluid equation, there is a nonnegative variable diffusion in the equations considered in this paper. Such a variable diffusion reflects the characteristic of the medium which may not be homogenous. By giving a generalization of the Gronwall inequality, the stability and the uniqueness of weak solutions to the non-Newtonian fluid equation with variable diffusion are studied. Since the variable diffusion may be degenerate on the boundary ∂ Ω, it is found that a partial boundary value condition imposed on a submanifold of ∂ Ω × ( 0 , T ) is enough to ensure the well-posedness of weak solutions. The novelty is that the concept of the trace of u ( x , t ) is generalized by a special way. UR - https://doi.org/10.3934/math.2022977 DO - 10.3934/math.2022977