Blow-up analysis of solutions for weakly coupled degenerate parabolic systems with nonlinear boundary conditions

Abstract

This paper is devoted to the study of the blow-up solutions of the following weakly coupled degenerate parabolic systems with nonlinear boundary conditions: ut=div|∇u|p∇u+f(x,u,v,t),vt=div|∇v|q∇v+g(x,u,v,t),(x,t)∈D×(0,T∗),∂u∂n=b(u),∂v∂n=d(v),(x,t)∈∂D×(0,T∗),u(x,0)=u0(x),v(x,0)=v0(x),x∈D¯.Here p>0,q>0, D is a bounded spatial region in Rn(n≥2), and the boundary ∂D is smooth. We mainly combine the maximum principles of the weakly coupled parabolic systems with the first-order differential inequality technique to discuss the blow-up phenomenon of the above problem. Sufficient conditions for the blow-up of the nonnegative solution (u,v) of this problem are given. In addition, for the nonnegative blow-up solution (u,v), we also obtain an upper bound on the blow-up time and an upper estimate of the blow-up rate.