The London Perl and Raku Workshop takes place on 26th Oct 2024. If your company depends on Perl, please consider sponsoring and/or attending.
 / 
Sim-OPT-0.64
River stage zero No dependents
/ Sim::OPT::Modish

NAME

Sim::OPT::Modish

SYNOPSIS re.pl use Sim::OPT::Modish;

  modish( "PATH_TO_THE_ESP-r_CONFIGURATION_FILE.cfg" zone_number surface_1_number surface_2_ ... );
  
  Example: 
  modish( "/home/x/model/cfg/model.cfg" 1 7 9 );

DESCRIPTION

modish is a program for altering the shading values calculated by the ESP-r simulation platform to take into account the reflections from obstructions. More precisely, modish brings into account the reflective effect of solar obstructions on solar gains in the ESP-r building models on the basis of irradiance ratios. Those ratios are obtained combining the direct radiation on a surface and the total radiation calculated by the means of a raytracer (Radiance) on the same surface.

How the program works. The effect of solar reflections is taken into account at each hour on the basis of the ratios between the irradiances measured at the models' surfaces in: a) the original model; b) a transitional model derived from that. The irradiances are calculated through Radiance and derive from the following building models: a) a model in which the solar obstructions have their true reflectivity and all the other surfaces (with the exception of the ground) are completely black; b) a model in which the solar obstructions and all the other surfaces (with the exception of the ground) are completely black. The value given by 1 minus those irradiance ratios gives the diffuse shading factors that are put in the ISH file in place of the original values. The original ISH's ".shda" files are not substituted. Two new files are added in the "zone" folder of the ESP-r model: the ".mod.shda" file is usable by ESP-r. It features the newly calculated shading factors; the ".report.shda" file lists the original shading factors and, at the bottom, the irradiance ratios from which the new shading factors in the ".mod.shda" file have been derived. Note that when the radiation on a surface is increased, instead of decreased, as an effect of reflections on obstructions, the shading factor will be negative.

Through the shell, modish has to be launched with a command like this: re.pl Them: use Sim::OPT::Modish; modish( "PATH_TO_THE_ESP-r_CONFIGURATION_FILE.cfg", zone_number, surface_1, surface_2, ..., surface_n ); An example of launch line may be: modish( "/home/x/model/cfg/model.cfg" 1 7 9 ); The path of the ESP-r model configuration path has to be specified in full, like in the example above. In calculating the irradiance ratios, the program defaults to: diffuse reflections: 1 ; direct reflections: 7; surface grid: 2 x 2; direction vectors for each surface: 1 ; distance from the surface for calculating the irradiances: 0.01 (metres); ratio of the of the original shading factor to the "new" shading factor under which the new shading factor is used to substitute the original one in the ".shda" file. If this value is 1, it is inactive, there is no threshold. These defaults are a compromise between quality and speed. They can be overridden in two manners: 1) by preparing a "modish_defaults.pl" file and placing it in the same directory of "modish.pl". The content of a configuration file for the present defaults, for example, would be constituted by the following line (note that after it a line of comment follows): @defaults = ( [ 2, 2 ], 1, 1, 7, 0.01, 1 );### i.e ( [ resolution_x, resolution_y ], $dirvectorsnum, $bounceambnum, $bouncemaxnum, $distgrid, $threshold ) 2) By specifying the settings from the command line at the launch inside square brackets: modish( "/home/x/model/cfg/model.cfg" 1 7 9 [ [ 2, 2 ], 1, 1, 7, 0.01, 1 ] ); The value "$dirvectorsnum" controls the numbers of direction vectors that are used for computing the irradiances at each point of each grid over the surfaces. The values that currently can be chosen are 1, 5 and 9. When the points are more than 1, they are evenly distributed on a hemisphere following a precalculated geodetic pattern. modish works with no limitation of number of surfaces, it can be used with complex geometries and takes into account parent and child surfaces. For the program to work correctly, the materials, construction and optics databases must be local to the ESP-r model. The files "fix.sh" "perlfix.pl" contained in the optw.tgz in the "example" directory MUST reside (i.e. be copied) in the folder from which modish is launched. Ihe ESP-r "e2rfile.F" source file of the ESP-r distribution should be checked before compilation for verifying that it calls these programs just after the Radiance materials file (".mat") has been created, i.e. just before the line "C Inside description file." (line 587 of ESP-r release 12.4) in the file "e2rfile.F" . If the following Fortran line is absent, it has to be added: system('./fix.sh') . Author: Gian Luca Brunetti, Politecnico di Milano - gianluca.brunetti@polimi.it. All rights reserved, 2015-16. This is free software. You can redistribute it and/or modify it under the terms of the GNU General Public License, version 2 or newer, as published by the Free Software Foundation.

EXPORT

"modish".

SEE ALSO

AUTHOR

Gian Luca Brunetti, <gianluca.brunetti@polimi.it>

COPYRIGHT AND LICENSE

Copyright (C) 2008-2017 by Gian Luca Brunetti and Politecnico di Milano. This is free software. You can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2 or later.