Angular Density Perturbations to Filled Type I Strong Explosions

Abstract

In this paper we extend the Sedov - Taylor - Von Neumann model for a strong explosion to account for small angular and radial variations in the density. We assume that the density profile is given by $\rho\left(r,\theta,\phi\right)=kr^{-\omega}\left(1+\varepsilon\left(\frac{r}{r_{0}}\right)^{q}Y_{lm}\left(\theta,\phi\right)\right)$, where $\varepsilon\ll1$ and $\omega\le\frac{7-\gamma}{\gamma+1}$. In order to verify our results we compare them to analytical approximations and full hydrodynamic simulations. We demonstrate how this method can be used to describe arbitrary (not just self similar) angular perturbations. This work complements our previous analysis on radial, spherically symmetric perturbations, and allows one to calculate the response of an explosion to arbitrary perturbations in the upstream density. Together, they settle an age old controversy about the inner boundary conditions