PALM - A PArallelized Large-Eddy Simulation Model for Atmospheric and Oceanic Flows

PALM is a large-eddy simulation (LES) model for atmospheric and oceanic flows which is especially designed for performing on massively parallel computer architectures. It can freely be used for scientific research.

Some of PALM's highlights are

• excellent scaling, so far tested up to 10000 cores
• online data analysis (during model runs) in order to avoid I/O bottlenecks
• topography realized on cartesian grid (allows for steep topography)
• non-cyclic horizontal boundary conditions available, including turbulence recycling method to allow for a turbulent inflow
• code can be switched to ocean version, including salinity equation and equation of state for seawater
• a parallelized Lagrangian particle model is embedded, which can be used for various applications (footprint calculation, simulation of cloud droplet growth, visualization, etc.)
• code has an interface which allows users to plug in their own extensions without modifying the default code

The original version of which was developed from 1997-1999 at IMUK. This model is optimized for use on massively parallel computers, and it is therefore very well suited for simulations with an extremely large number of grid points. The current supercomputer of the North German Supercomputing Center "Norddeutscher Verbund für Hoch- und Höchstleistungsrechnen" (HLRN), an SGI-ICE machine with 12000 cores, allows calculations with up to 4096³ grid points.
Our research focusses on the analysis of micro- and mesoscale turbulent boundary layers. Other key parts of our work include numerical improvements of PALM, in particular parallelized numerical schemes, and the development of software systems that are able to effectively visualize the extremely large data amount that is typical of parallelized models.

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Getting Help

If you experience problems with PALM or if you like to request new enhancements, feel free to create a new ticket or have a look in our tickets section. Furthermore, we might provide a list of frequently asked questions (FAQ) in future.

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PALM-related Downloads

In the download section you can find documentations of selected parts of the model source code as well as animations and presentations from workshops.