ADINC: An implicit Lagrangian hydrodynamics code

This paper presents and describes a new software package called ADINC(ADiabatic and INCompressible flows) which is designed to solve the mass, momentum, and adiabatic energy equations for a rather general one-dimensional fluid system. A fully Lagrangian, conservative hydrodynamics algorithm is incorporated so that interfaces between different materials can be followed accurately. The Courant timestep limit for sound waves is overcome by implicit time differencing with a quadratically convergent iteration for nonlinear time centering. Listings of the pertinent ADINC routines, and a general driver test program are included in the appendices. A rather general analytic equation of state routine is included which handles adiabatic gases, slightly compressible solids, and even the incompressible limit in adjacent cells. The test program has provision for up to five layers of material. Three test problems are presented in the appendices with representative outputs for code verification.