Global classical solutions to the one-dimensional compressible fluid models of Korteweg type with large initial data

This paper is concerned with the global existence of classical solutions with large initial data away from vacuum to the Cauchy problem of the one-dimensional isothermal compressible fluid models of Korteweg type with density-dependent viscosity coefficient and capillarity coefficient. The case when the viscosity coefficient μ(ρ)=ραμ(ρ)=ρα and the capillarity coefficient κ(ρ)=ρβκ(ρ)=ρβ for some parameters α,β∈Rα,β∈R is considered. Under some conditions on α,βα,β, we first show the global existence of large solutions around constant states if the far-fields of the initial data are the same, while if the far-fields of the initial data are different, we prove the global stability of rarefaction waves with large strength. Here global stability means the initial perturbation can be arbitrarily large. Our analysis is based on the elementary energy method and the technique developed by Y. Kanel' [29].