Thursday, September 29, 2011

Release version 1.2.2 of Tonatiuh


We just released version 1.2.2 of Tonatiuh. This new release of Tonatiuh is another minor release of the program. It solvers a series of minor bugs of the program, and the following major ones:  

  • The inappropriate sizing of the ray casting surface. In the previous release of Tonatiuh when the user modified the concentrating geometry, adding or substracting surfaces, the ray casting surface was not resized accordingly. This behavior has been corrected in the present release, so that the size of the ray casting surface is always adjusted to the concentrating geometry in order to increase the probabilities that the rays that are cast hit the concentrating geometry, decreasing the time needed to converge to accurate estimate of variables which are of interest to the user, such as the total power on target, the flux distribution in a given surface, etc.

  • The erroneous generation of the seven-tuples of the photon map. In the previous release of the program, the field of the seven-tuple of a given photon that was associated with the side of the surface that the photon was hitting was incorrectly always set to -1, instead of setting it to 0 if the photon was hitting the rear side of the surface or to 1 if it was hitting the front side of the surface. This has been corrected in the present release of the program.

  • The undesired possibility for the user of being able to associate a tracker to a TShapeKit. In the previous release of the program the user could select a TShapeKit and then include within it a Tracker element, with the operation resulting in a program crash, since Tracker elements are only intended to be use as child of TSeparatorKit elements. In the present release of the program, the program behavior has been modified to guarantee that the user can only associate a Tracker to a TSeparatorKit.

  • The incapacity of the program to open Tonatiuh files containing TShapKit nodes that do not have associated a TShape node. In the previous release of the program, if the user closed a Tonatiuh session having defined a TShapeKit node without associating to it a valid TShape node as a child, the program was not able to subsequently open the given Tonatiuh file any more. The present release correct this.
  • The crash of Tonatiuh when the user aborted the operation of creating a Bezier patches TShape node. In the previous release of the program, when a user was defining a Bezier patches TShape node, if she or he was in the process of entering the path to the data file containing the geometric information to create the Bezier patches and decided to abort that operation Tonatiuh crashed. The present release correct this error, and when the user aborts the entering of the geometry data filename, the program just do not create the Bezier patches TShape node.
As a result of correcting all the mentioned bugs, we hope that this new release of Tonatiuh will be a much more stable version of the program than previous ones. 

As promised, we are providing 32 and 64-bit installers of this new release of the program for the three major operating systems: Windows, Linux, and Mac. The installer for the Maxc OS is the same for both the 32 and 64 version of the program. While we have been able to test the 64-bit version of Tonatiuh release 1.2.2 for Windows 7 and Linux, we have not tested the 64-bit version of Tonatiuh for the Mac OS. Thus, please, let us know how it work for you.

In October 23 we expect to release the next version of the program. Please, let us know your suggestions for the new functionality you would like to see incorporated in the program.

Monday, September 12, 2011

The size of the focal spot of an ideal parabolic dish solar concentrator

Tonatiuh can be used to explore diverse aspects of solar concentrating systems and to answer questions regarding those systems. In the link to the small document entitled "The size of the focal spot of an ideal parabolic dish solar concentrator" the question of what is the size of the spot of concentrating sunlight that a parabolic dish produces in a plane normal to its optical axis and at a distance equal to its focal length is answered.

The link also shows how Tonatiuh can be used to provide an approximate numerical answer to the question and analyzes the associated errors, which are shown to be relatively low (< 0.35%) even when the number of rays traced is not exceedingly large (< 65 million rays).