# Verification Studies for the Noh Problem using Non-ideal Equations of State and Finite Strength Shocks

## TL;DR

This paper extends the Noh verification problem to realistic equations of state and uses self-similarity solutions for code verification of shock simulations in various geometries.

## Contribution

It develops exact solutions for the Noh problem with non-ideal EOSs, enabling more realistic and comprehensive code verification for shock physics.

## Key findings

- Exact solutions for non-ideal EOSs in Noh problem
- Applicable to planar, cylindrical, and spherical shocks
- Used for verification of the FLAG hydrocode

## Abstract

The Noh verification test problem is extended beyond the commonly studied ideal gamma-law gas to more realistic equations of state (EOSs) including the stiff gas, the Noble-Abel gas, and the Carnahan-Starling EOS for hard-sphere fluids. Self-similarity methods are used to solve the Euler compressible flow equations, which in combination with the Rankine-Hugoniot jump conditions provide a tractable general solution. This solution can be applied to fluids with EOSs that meet criterion such as it being a convex function and having a corresponding bulk modulus. For the planar case the solution can be applied to shocks of arbitrary strength, but for cylindrical and spherical geometries it is required that the analysis be restricted to strong shocks. The exact solutions are used to perform a variety of quantitative code verification studies of the Los Alamos National Laboratory Lagrangian hydrocode FLAG.