Release version 1.1.5 of Tonatiuh

We just released version 1.1.5 of Tonatiuh. This new release version of Tonatiuh is a minor release of the program. It corrects  memory leaks and other minor program bugs. It also incorporates the following new two main features:

• A tracker suited to simulate the tracking behavior of Fresnel mirrors.
• The automatic sizing of the input scene aperture, i.e., the surface from which the sun rays are cast towards the concentrating system.

In this new release, the Linux 64 bit version of the program incorporates for the first time the self-updating functionality of the program that was incorporated in the 32 bit version of the program few releases ago.

If you are using a 32 bit version of Tonatiuh and you already installed in your computer Tonatiuh release 1.1.4, you do not need to download the installer for the new release of the program, just start Tonaiuh's release 1.1.4, go the the Help menu in the menu bar, click on “Check for updates” option, and follow the instructions that will appear on the screen. Of course, for that to work you have to be connected to Internet.

Although our intentions are to develop and make available to everyone the 64 bit version of Tonatiuh not only for Linux, but also for window and Mac OS X. We are encountering difficulties to compile Tonatiuh in a 64 bit Windows and Mac OS X system, and we cannot advance a date at which these difficulties will be resolved.

In defining the features that have been added to release 1.1.5 of Tonatiuh we have taken into account the suggestions of the users expressed both in Tonatiuh's user group and in the corresponding “Tonatiuh raytracer product ideas page” at Google Moderator

Release of version 1.1.4 of Tonatiuh

We just released version 1.1.4 of Tonatiuh. This new release version of Tonatiuh is a minor release of the program. It corrects some memory leaks and other minor bugs of the program and incorporates a large number of internal code improvements targeted to improve the program's speed in all platforms.

This is the first release of Tonatiuh for which, in addition to the 32-bit versions of the program targeted to Windows, Linux, and Mac, we are also releasing a 64-bit binary of the program targeted to Linux.

In the following weeks we will be adding the corresponding 64-bit version of the program targeted to Windows and Mac.

If you already installed in your computer Tonatiuh release 1.1.3, you do not need to download the installer for the new release of the program, just start Tonaiuh's release 1.1.3, go the the Help menu in the menu bar, click on “Check for updates” option, and follow the instructions that will appear on the screen. Of course, for that to work you have to be connected to Internet.

As shown in the following figure, this release is faster than previous releases of the program. Under Windows, it achieves a 22.4% reduction in the average time it needs to cast 6 million rays while simulating the optical behaviour of NREL's Solar Furnace in the three different computers in which the program was tested. Under Linux this average time reduction reached 16.7%.

From Tonatiuh Blog Figures

As always, should you find bugs or errors in the program or in any of its plug-ins, please, take the time to report them, in the "Issues" section of Tonatiuh's website at Googlecode. Furthermore, should you have suggestions to improve the program or increase its functionalities, please, let us know, either by adding comments to this post, or better by opening an appropriate discussion in Tonatiuh's user group.

Best regards,

Release of version 1.1.3 of Tonatiuh

We just released version 1.1.3 of Tonatiuh. This is a minor release version of the program. Its main characteristics are the following:

• It corrects a bug detected in the program's Update Manager of version 1.1.2, which precluded the Update Manger to fulfill its function.
• It introduces changes in the core of the Tonatiuh program that improves and simplified its structure.
• It adds two new shape plug-in to the list of standard Tonatiuh plug-ins: The trough and the surface of revolution versions of the standard non-imaging Trumpet-like concentrator.

Because of the bug in the Update Manager of Tonatiuh version 1.1.2, the new release of the program (version 1.1.3) has still to be downloaded and installed as in previous versions, i.e., by downloading the installer from the "Downloads" tab of the Tonatiuh website and executing it.

As usual, the trough or translational sweeping version of the trumpet-like concentrator plug-in represents only one-side of the translational sweeping trumpet. This allows Tonatiuh users to define complex n-sided trumpet-like concentrators by combining several of these sides and selecting appropriately their input and output lengths.

The following figure shows the parameters that are used in Tonatiuh to define the translational sweeping version of the trumpet-like concentrator shape plug-in added to the new release of the program.

From Tonatiuh Blog Figures

Contrary to others rotational geometry standard Tonatiuh shape plug-ins, the rotational geometry version of the trumpet-like plug-in those not allow the user to define the rotational sweeping angle, but assumes that this angle is always 360 degrees. This limitation will be corrected in future versions of this plug-in.

The following figure shows the parameters that are used in Tonatiuh to define the rotational sweeping version of the trumpet-like concentrator plug-in added to the new release of the program.

From Tonatiuh Blog Figures

As always, if you find bugs in Tonatiuh or in any of its plug-ins, please, take the time to report those errors using the "Issues" tab in Tonatiuh's website at Googlecode. Furthermore, if you have suggestions on how to improve the program or increase its functionalities, please, let us know, either by adding comments to this post, or better by participating on the corresponding discussion of the Tonatiuh users group.

Best regards. Enjoy!

Parameters of the CHC plug-in

In Tonatiuh release 1.1.2, the latest one as of the writting of this post, we have introduced a new shape plugin, the 2D Compound Hyperbolic Concentrator plug-in, which in Tonatiuh is called "Trough_CHC".

The mathematical model defining the CHC implemented in the Trough_CHC plug-in is taken from the following article:

William L. Eichhorn, "Generalized conic concentrators", Appl. Opt. 21, 3887-3890 (1982). http://www.opticsinfobase.org/abstract.cfm?URI=ao-21-21-3887

The plug-in, when added in Tonatiuh as a child to a TShapeKit node, implements one side of a 2D Compound Hyperbolic Concentrator.

From Tonatiuh Blog Figures

As indicated in the above figure, the geometry is defined by the following 5 parameters:

• r1, the distance in the x-direction from the origin of the CHC implicit local coordinate system to the middle of the lower border, oriented in the z-direction and centered around the x-axis. In the negative x-direction, r1 is also de distance in x-axis where the focus of the branch of the hyperbola represented by the plug-in is located (point F in the figure).
• p1,  the distance in the x-direction from the origin of the CHC implicit local coordinate system to the middle of the the upper border, oriented in the z-direction and centered around the x-axis.
• lengthX1, the length of the lower border, oriented in the z-direction and centered around the x-axis.
• lengthX2, the length of the upper border,oriented in the z-direction and centered around the x-axis.
• height, the distance in the y-direction between the lower and the upper border.

By defining lengthX1 and lengthX2 appropiately, it is possible to combine several trough CHC plug-ins to represent a large variety of hyperbolic concentrators. As an example, the figure below shows an Hexagonal CHC constructed using six troguh CHC plug-ins.

From Tonatiuh Blog Figures

Tonatiuh’s website number of visits and bounce rate are growing fast

Tonatiuh’s website started on June 28, 2008. Thus, we are currently in the day 143 of the third year since the opening of the website. With only 39% of the third year of the website passed by, today the number of visits to the Tonatiuh website has exceeded the total number of visits to the website during the previous year. The fact that the number of visits to the Tonatiuh’s website is increasing at an exponential rate is an indication that Tonatiuh is increasingly kwon and used all over the world.

From Tonatiuh Blog Figures

Another indication of the consolidation of Tonatiuh as a reference program for the analysis of the optical and energy behavior of solar concentrating systems is the continuous increase in Tonatiuh's website “Bounce Rate”. According to the information shown in Figure 1, more than 63% of Tonatiuh website’s visitors are recurrent visitors.

Release of version 1.1.2 of Tonatiuh

We just released version 1.1.2 of Tonatiuh. This is a minor release version of the program. Its main characteristics are the following:

• It incorporates an Update Manager, which allows the users to check if there is available a newer version of the program than the one she or he is using, and to download it in case it is available.
• It adds a new shape plug-in to the list of Tonatiuh standard shape plug-ins. This new shape plug-in named "ShapeTroughCHC" allows the user to create trough-like Compound Hyperbolic Concentrators.
• It fixes the error associated with the lack of immediate response of a Tracker to user-induced changes in the transformation of its parent TShapeKit separator or in any of its ancestors.
• It fixed the error associated with the brief appearance of a ghost window when opening the Sun Position Calculator.

Figure 1 shows a view of a parabolic trough working in tandem with a Compound Hyperbolic Concentrator acting as a secondary concentrator.

From Tonatiuh Blog Figures

We are starting a tutorial series to illustrate the use of Tonatiuh

To illustrate the use of Tonantiuh we are starting today a tutorial series, which will be posted in the wiki of the main Tonatiuh website (tonatiuh.googlecode.com).

The tutorial that starts the series will explain how to use Tonatiuh to model and analyze a tower system with 500 one-facet small heliostats.

From Tonatiuh Wiki Figures

This tutorial will explain how to insert "tracker" plug-ins in the modeling of the heliostat field to ensure that when the user changes the sun position the heliostats are  automatically reoriented so that they keep directing their reflected sunlight towards the receiver located on top of the tower.

In addition, the tutorial will also explain how to use the scripting capabilities of Tonatiuh to automate the generation of an optical efficiency matrix for the solar heliostat field.

To access the index of the tutorial series, please, follow this link.

Please, give us feedback, so that we can continue improving Tonatiuh, and providing you the tools and information you need to use it.

Best regards,