%\documentstyle[11pt]{article} %\input{psfig} %\begin{document} %\setcounter{page}{1} \newpage \begin{center} \Large{\bf I. INTRODUCTION} \end{center} \addcontentsline{toc}{section}{\protect\numberline{I.}{\bf ~Introduction}} \vspace*{5mm} \noindent\rm This user's guide describes how to use TITAN which is a modern computational tool for generating accurate solutions of the one-dimensional radiation hydrodynamical equations in a broad variety of initial and boundary conditions. It employs an implicit adaptive grid procedure to deal with the multiple length and time scales inherent in such problems. The grid is designed to detect, resolve, and track nonlinear features of the flow. TITAN is intended for use by the astrophysical community both as a research and a teaching tool. TITAN comes with a suite of test problems that cover purely hydrodynamical and radiation hydrodynamical calculations as well as time dependent radiation transport through static media. An abbreviated version of this guide is published in: {\flushleft \noindent\rm Adaptive Mesh Radiation Hydrodynamics with TITAN, M. Gehmeyr and\\ \hspace{10mm}D. Mihalas, \it Physica D, \bf??, \rm??, 1994} \vspace{5mm} \noindent\rm In what follows, the one-dimensional equations of radiation hydrodynamics are briefly reviewed, the essential numerical methods of the code are highlighted, the suite of test problems, and how to run and modify them, is described, and ways how to set up new problems are suggested. Further details about the equations used in the code are given in the TITAN Code Reference Manual.\\ \noindent\rm To assist the reader we write all ordinary physical and mathematical variables in {\it italic type}, and {\tt FORTRAN} quantities in {\tt typewriter type}. Further, we have highlighted all parts of the code that are explicitly discussed, as well as all examples that could be viewed on a monitor, with a \psfig{file=box1.ps,rheight=10bp,rwidth=1bp,height=5mm,width=30mm,silent=} gray background. %\end{document} .