Similarity criteria for the laboratory simulation of supernova hydrodynamics

The conditions for validity and the limitations of experiments intended to simulate astrophysical hydrodynamics are discussed, with application to som e ongoing experiments. For systems adequately described by the Euler equati ons, similarity criteria required for properly scaled experiments are ident ified. The conditions for the applicability of the Euler equations are form ulated, based on the analysis of localization, heat conduction, viscosity, and radiation. Other considerations involved in such a scaling, including i ts limitations at small spatial scales, are discussed. The results are appl ied to experiments aimed at simulating three-dimensional hydrodynamics duri ng supernova explosions and hydrodynamic instabilities in young supernova r emnants. In addition, hydrodynamic situations with significant radiative ef fects are discussed.