Electronic Journal of Differential Equations, Vol. 2025 (2025), No. 74, pp. 1-18. Title: Zero-viscosity-capillarity limit for the contact discontinuity for the 1-D full compressible Navier-Stokes-Korteweg equations Authors: Jiaxue Chen (Nantong Univ., Nantong, China) Yeping Li (Nantong Univ., Nantong, China) Rong Yin (Nantong Univ., Nantong, China) Abstract: In this article, we study the zero-viscosity-capillarity limit problem for the one-dimensional full compressible Navier-Stokes-Korteweg equations. This equation models compressible viscous fluids with internal capillarity and heat conductivity. We prove that if the solution of the inviscid Euler equations is piecewise constants with a contact discontinuity, then there exist smooth solutions to the one-dimensional full compressible Navier-Stokes-Korteweg system which converge to the inviscid solution away from the contact discontinuity. It converges a rate of $\epsilon^{1/4}$ as the the viscosity $\mu=\epsilon$, heat-conductivity coefficient $\alpha=\nu\epsilon$ and the capillarity $\kappa=\lambda\epsilon^2$ and $\epsilon$ tends to zero. The proof is completed using the energy method and the scaling technique. Submitted May 19, 2025. Published July 16, 2025. Math Subject Classifications: 76W05, 35B40. Key Words: Full compressible Navier-Stokes-Korteweg equation; compressible Euler system; zero-viscosity-capillarity limit; contact discontinuity.