The latest version of the GRAL dispersion model, 24.04, has been released and it includes several updates and bug fixes. GRAL, a Lagrangian dispersion model, is extensively used for simulating pollutant dispersion, and these updates are expected to enhance its reliability in various environmental scenarios.
A significant fix in version 24.04 addresses an issue that caused incorrect concentration calculations within buildings. This bug, present since version 23.11, affected flat terrain and certain building configurations. Correcting this issue ensures that GRAL can provide more accurate simulations in urban settings where building interactions play an important role.
Additionally, a bug related to wind speeds near the ground has been fixed. Previously, transferring the GRAMM wind profile to the GRAL grid resulted in excessively high wind speeds near the ground. This correction will lead to more realistic wind speed profiles in GRAL simulations, improving the model's overall accuracy in representing ground-level dispersion.
The plume rise calculation has also been adjusted. Since version 23.11, the plume rise for very small point sources was inaccurately high. This update corrects the plume rise, leading to more accurate predictions of pollutant dispersion from small sources, which is vital for precise environmental impact assessments.
GRAL 24.04 also introduces a change in its distribution method. For Linux users, the release is no longer published as an all-in-one file by default. Users are now required to install the .NET8 Runtime to use the model. However, for Windows users, a single-file version is still available.
For detailed information on the new features and bug fixes, users are encouraged to refer to the release notes on the GRAL homepage. Additional resources, such as the GUI manual and the GRAL and GRAMM documentation, provide comprehensive guidance on utilizing the model effectively.
The GRAL development team extends their gratitude for user feedback and support, which have been instrumental in driving these improvements. Special thanks go to Markus Kuntner for his efforts in implementing the new features and resolving the issues.
Finally, it's worth noting that the complete source code for GRAL is available under the GNU/GPL 3 license. Users can access it on the project's GitHub repository, promoting transparency and collaboration within the user community.
Download this free and open source model here.
