$495 Standard Version (600 nodes)
Call for pricing of versions for larger sites

MOTRANS is a finite element model to simulate the flow of water, dense or light nonaqueous phase liquid (NAPL) and air, and transport of up to five partitionable species in two-dimensional vertical sections through saturated and unsaturated zones in Cartesian or radial coordinates. Gas phase flow may be considered explicitly or assumed to be at constant pressure. The code solves flow equations at each node only for phases that are undergoing changes in pressures and saturations above specified tolerances using a new "adaptive solution domain" (ASD) method. NAPL flow equations are thus locally eliminated if NAPL is absent or exists at a residual saturation. Convective-dispersive transport in water, NAPL and gas phases are analyzed assuming local equilibrium partitioning among the fluid phases and with the solid phase or optionally using a first-order non-equilibrium mass transfer model. Interphase mass transfer and compositional dependence of phase densities are considered. MOTRANS utilizes a three-phase van Genuchten model for saturation-pressure -permeability relations and considers hysteresis in oil permeability due to oil entrapment. It has options for simulating water flow only, oil flow with steady-state water, coupled oil-water flow, or coupled air-oil-water flow.

The MOTRANS user interface includes menu-driven pre- and post-processing programs. It allows simplified data file generation; graphical input of spatially variable properties and time-dependent boundary conditions. The MOTRANS user interface includes a user-transparent interface to GRAPHER/SURFER for custom graphic output; plots of cumulative mass in system versus time; contour plots of phase saturations and species concentrations.

MOTRANS is a proprietary program distributed on DOS formatted disks containing executable image, and example data sets. The program is extensively documented.

SYSTEM REQUIREMENTS

Intel 80486 based computer with math coprocessor, 8 Mb extended memory, DOS 3.3 or higher, VGA graphics.

Author: Environmental Systems and Technologies, Inc.