S. E. Ingebritsen D.O. Hayba 1994 Quantitative modeling of the deep parts of magmatic- hydrothermal systems has been limited by the lack of publicly available, documented computer models for multiphase, high-temperature flow. This report documents HYDROTHERM, a finite-difference model for three-dimensional, multiphase flow of pure water and heat over a temperature range of 0 to 1,200 degrees Celsius and a pressure range of 0.5 *0 10,000 bars.HYDROTHEP*M is an extension of multiphase geothermal models developed by the U.S. Geological Survey in the 1970's. It solves numerical approximations to mass- and energy-balance equations that are posed in terms of pressure and enthalpy. Major assumptions are that the rock matrix can be treated as a porous medium; that water and rock are in thermal equilibrium; and that capillary pressure is negligible. application/pdf 10.3133/wri944045 en U.S. Geological Survey ; USGS Earth Science Information Center, Open-File Reports Section [distributor], The computer model Hydrotherm, a three-dimensional finite-difference model to simulate ground-water flow and heat transport in the temperature range of 0 to 1,200 degrees C reports