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ENVI-met Model Architecture
This page gives an overview over the technical aspects and modules used in ENVI-met Version 3.
| Atmosphere | Soil System | Vegetation | Surfaces | Biometeorology | Behind the Scenes |
|---|---|---|---|---|---|
| Wind | Temperature | Foliage Temperature | Ground Surface Fluxes | PMV-Value | The Mathematics |
| Temperature | Water Flux | Heat and Vapor Exchange | Fluxes at Walls / Roofs | The climBOTs | |
| Vapor Turbulence Pollutants | Water Bodies | Water Interception and Transport | Heat Transfer through Walls |
Introduction
ENVI-met is a three-dimensional non-hydrostatic model for the simulation of surface-plant-air interactions not only for but especially inside urban environments. It is designed for microscale with a typical horizontal resolution from 0.5 to 10 m and a typical time frame of 24 to 48 hours with a time step of 10 sec at maximum. This resolution allows to analyze small-scale interactions between individual buildings, surfaces and plants.
The model calculation includes:
- Shortwave and longwave radiation fluxes with respect to shading, reflection and re-radiation from building systems and the vegetation
- Transpiration, Evaporation and sensible heat flux from the vegetation into the air including full simulation of all plant physical parameters (e.g. photosynthesis rate)
- Surface and wall temperature for each grid point and wall
- Water- and heat exchange inside the soil system
- Calculation of biometeorological parameters like Mean Radiant Temperature or Fanger's Predicted Mean Vote (PMV) - Value
- Dispersion of inert gases and particles including sedimentation of particles at leafs and surfaces
Buildings, vegetation, soils/ surfaces and pollutant sources can be placed inside the model area. Besides of natural and artificial surfaces, the model is also able to handle water bodies.
ENVI-met runs on WINDOWS NT/2000/XP platforms with a minimum of 128MByte RAM. Multiple-Processors Systems are not supported (=do not run faster than single ones).The exact memory requirements depend on the number of grid points used. A rough overview of the memory requirements is:
| 60 x 60 x 30 Grids | 128 Mbytes |
|---|---|
| 80 x 80 x 30 Grids | 128 Mbytes |
| 120 x 120 x 30 Grids | 256 Mbytes |
| 130 x 130 x 30 Grids | 256 Mbytes |
| 200 x 200 x 25 Grids | 512 Mbytes |
| 250 x 250 x 25 Grids | 1 GByte |