DWSIM Development Blog

The Binary Data Regression utility is now available for Linux and Mac OS X! Grab your copy of the latest DWSIM Mono Edition here.

Build 4410 is available for Windows and includes a new Property Package with the PRSV2 equation of state. So, since Build 4258 we have the following list of changes:

- [NEW] Added the Compound Creator Utility and corresponding user database structure (work in progress)

- [NEW] Added a Binary Data Regression utility (work in progress)

- [NEW] New Property Package: Peng-Robinson-Stryjek-Vera 2 (PRSV2)

- [NEW] Added feature request #3409646 (Name given to Material Objects)

- [CHG] Enhanced Unit Set Creator to start with units from the current system

- [CHG] Changed density input from Specific Gravity to API Gravity on the Dist. Curves Characterization Utility

- [CHG] Rewritten solver logic increases calculation speed by 35% (Cavett sample)

- [FIX] Fixed infinite volumetric flow on first Material Stream calculation through the property grid

- [FIX] Fixed Adjust and Spec Ops not showing anything on the property grid

- [FIX] Fixed Lee-Kesler Cp/Cv calculation

- [FIX] Fixed Distillation Curves Petroleum Characterization Utility

- [FIX] Fixed Pipe Segment model overall HTC calculation and liquid phase volume retrieval

- [FIX] Fixed Spanish translation of the Object Palette

- [FIX] Fixed bug #3409641 (Call to Terminate missing)

- [FIX] Fixed bug #3409637 (Collection Count method called twice in a row)

- [FIX] Fixed bug #3409628 (ICapeUtilities queried twice in a row)

There is also a new tutorial on how to use the Data Regression utility => sourceforge.net/apps/mediawiki/dwsim/index.php

Build 4407 Beta is up and you can get it here => http://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%202.0/DWSIM_bin_v21_b4407_beta.exe/download

Changes since 4404:

- [CHG] Added LLE support and initial estimates calculation using UNIFAC structure to the Data Regression Utility

- [CHG] Changed density input from Specific Gravity to API Gravity on the Dist. Curves Characterization Utility

- [FIX] Fixed solver not recalculating outlet streams

- [FIX] Fixed infinite volumetric flow on first Material Stream calculation through the property grid

- [FIX] Fixed Adjust and Spec Ops not showing anything on the property grid

I've also included some data regression samples, just check them on the "samples" folder. Feedback here please => http://sourceforge.net/projects/dwsim/forums

This time I've added the option to calculate initial estimates for NRTL/UNIQUAC regression using UNIFAC structure information. Also added were the so important "title" and "description" textboxes, just in case you want to specify were your data came from, what and why are you doing the regression, and so on.

LLE data regression is just plain HARD. I had to add the possibility of estimating initial values for the interaction parameters so the flash algorithm can return two liquid phases right from the start and finish the optimization successfully. You better have good initial estimates, otherwise the regression will fail miserably.

If you want to try the new compound creator and data regression utilities, you can download the newest beta build here - there are some fixes too. Please note that this is still work in progress and, as such, some new features are not fully working while the rest needs testing and feedback.

Changes since Build 4358:

- [NEW] Added the Compound Creator Utility and corresponding user database structure (work in progress)

- [NEW] Added a Binary Data Regression utility (work in progress)

- [NEW] Added feature request #3409646 (Name given to Material Objects)

- [CHG] Rewritten solver logic increases calculation speed by 35% (Cavett sample)

- [FIX] Fixed Lee-Kesler Cp/Cv calculation

- [FIX] Fixed Distillation Curves Petroleum Characterization Utility

- [FIX] Fixed Pipe Segment model overall HTC calculation and liquid phase volume retrieval

- [FIX] Fixed Spanish translation of the Object Palette

- [FIX] Fixed bug #3409641 (Call to Terminate missing)

- [FIX] Fixed bug #3409637 (Collection Count method called twice in a row)

- [FIX] Fixed bug #3409628 (ICapeUtilities queried twice in a row)

Here is a screenshot of the new data regression utility. In its first iteration, only binary equilibrium data will be supported, and I'm still trying to figure out how to calculate NRTL and/or UNIQUAC parameters from LLE data. It won't be easy because it is not guaranteed that the flash calculation will always return two liquid phases (and no vapor)...

Ths is work in progress, I'm now polishing the interface and checking if the code is working for all possible combinations of exp. data and model selection.

DWSIM 2.1 will include solver improvements (up to 35% faster in some cases), bug fixes, translation corrections and a new Data Regression Utility.

The data regression utility will regress experimental VLE/LLE data for mixtures and temperature-dependent properties for single components. The user component creator and hypo generator will be merged together into this new utility - at least that's the idea.

The new welcome screen will be something like this, since I think I'll leave the DRU in the same window level as a steady state simulation - it means not a simulation utility but rather a higher level one, since it will enable the user to create, edit and store new components and databases for all simulations.