VOLTRA upgrade info

Version 6.3w

• Improved more stable calculation of systems with ventilation flows.

Version 6.2w

• Diffuse solar reflection also possible in solar zone (of type BC_SKY).
• Sun obstacles (as in CAPSOL and BISTRA), defined as sky hemisphere regions, which block direct solar radiation and decrease diffuse solar irradiation.
• Import BISTRA data.

Version 6.1w

• Solar processor adapted to use of 2D geometries (SECTRA).
• Adjust coordinates of output nodes and output blocks after any grid operation.

Version 6.0w contains 3D solar processor

Global info pages

• Solar load on walls
• Solar load through windows
• Temperatures due to solar load

List of upgrade additions

• Same solar radiation climate data files as in CAPSOL (global and diffuse radiation on a horizontal surface).

• Input required of north orientation.

• Calculation of sun position and visualization of shadows cast by direct sun light.
  Creation of AVI animation file of shadows over calculation period.

• Additional material properties required: reflection factor (may be a function of the angle of incidence), transmission factor (to indicate a transparent material).

• Calculation and visualization of absorbed solar fluxes on material surfaces due to solar radiation.
  Direct solar radiation on an exterior material surface depends on geographical location, solar radiation climate data, day of year, clock time, surface orientation.
  Diffuse solar radiation on an exterior material surface depends on the view factor to the open sky and is calculated using Muneer’s radiation model (also used in CAPSOL).
  Reflected radiation (of direct and diffuse incident radiation) at an exterior material surface is lost (as in CAPSOL).  An input parameter (“ground reflection factor”) allows to take into account the reflected radiation from the environment.
  Radiation on transparent materials are transmitted to internal zones.
  Direct radiation is projected on internal walls following the solar rays.
  Diffuse radiation is distributed on all internal walls proportional to the view factors.
  All reflected radiation at an interior material surface is diffuse and is redistributed to the other interior surfaces proportional to the view factors.
  The scheme of successive internal reflections and transmissions is solved using a radiosity method.
  The view factors can be obtained from a prior view factor calculation using a coarser grid (to speed up the processing time and reduce the required memory space).
  The absorbed solar fluxes can be output to an AVI animation file or output to a text file.

• The absorbed solar fluxes can be used as boundary conditions for a thermal simulation (calculation of temperatures).  In this way solar heat gains on the thermal behaviour of a construction can be studied.

• The format of view factor file is modified.

Version 5.0w

• Contains functionality of TRISCO v11.0w (easier input editing & better graphic feedback).
• New type of material (requires RADCON module): transparent material (conduction + radiation), useful for small air cavities of irregular shape (instead of materials of type EQUIMAT).
• New type of boundary condition: material with given temperature (function) or heat power density.
• No function references required for constant numeric input values.
• Function Graph window as visual feedback of the input in the Functions window, with zoom facilities.
• Image window: interactive view of temperature value (after calculation) at cursor location per time step.
• Undo/redo edit actions.
• View factors calculation: view factors in a fine grid can be obtained through interpolation of view factors in a coarser grid (to overcome the quadratic proliferation of view factors in a fine calculation grid).
• Graphic output:
  clip colours (to hide certain material layers, to get a better inside view of the object);
  view heat fluxes in material cutoff planes.

Version 4.0w

• Temperature dependent material properties (thermal conductivity, specific heat), which are useful in e.g. fire simulations.

• Simulation of ventilation flows through different air zones following user-defined ventilation paths.  The ventilation volume flow rates refer to time dependent functions.  The simulation of ventilation flows allows the study of heating and cooling of objects due to ventilation systems.

Version 3.1w

• Two new types of boundary conditions:
  1. Enclosures with unknown temperature and global surface heat transfer coefficient
      (type BC_FRE_S).
  2. Border faces between colours having a fixed temperature function course or heat flux
      function course (“borderface BCs”).

• New split mesh functions (Grid > Split Mesh max… and Grid > Split All max…).

• Graphical feedback in the Image window of a selected item in another edit window can be toggled on or off (Image > Hide Selection Outline).

Version 3.0w

• Developed for Microsoft Windows (Windows 95, Windows 98, Windows NT, Windows 2000, and upwards).

• Through another system solution technique, much larger systems can be solved.  The node capacity is of the same order of magnitude as in TRISCO: 1 000 000 nodes and more.

• The calculation is at least 50 times faster.

• The RADCON module can be used.

• Most of the functionality of the Windows version of TRISCO (i.e. from version 8 up) is also available in VOLTRA (e.g. choice of language, 3D preview of the geometry when selecting data files, image feedback window, zoom functions, block transformations, automatic calculation of equivalent thermal conductivities of cavities and convective heat transfer coefficients in air cavities, batch calculation, output bitmaps with user-defined resolution).

• Built-in converter to import data from previous SECTRA and VOLTRA versions and from TRISCO (from version 8 up).

• A graphic preview of the internal function definitions is possible.

• The concept of line and plane definitions is changed into the definition of output blocks.

• Intermediate solution files can be saved on hard disk, and are useful for the production of animation sequences from different points of view.

• *.avi files of graphic animations with a user defined resolution can be written.  These .avi files can be viewed using Windows Media Player or another tool.

• Graphs of temperature or heat flow courses as a function of time are not directly possible within VOLTRA, but can be made e.g. using Microsoft Excel.