Release notes
APM 1.2.0 (7 February 2026 - latest)
Improved trailing edge detection algorithm.
APM is now free for non-commercial use. The free version of APM is limited to 5000 panels and 50 unsteady timesteps. Control surface, actuator disk, and probe definitions are disabled. The vortex particle wake option, the symmetry option, and the restart from checkpoint options are disabled.
APM 1.1.0 (2 November 2024)
Improved control surface morphing algorithm. Control surface element detection was improved for control surfaces with swept hinges.
Added wake_particle_smoothing_radius option in the configuration file.
Minor performance improvements.
APM 1.0.9 (2 March 2024)
Added support for UCD and WRL mesh formats. By default, APM will try to read a mesh in STL format. If no mesh in STL format is present, APM will try to read a mesh in UCD format. If no mesh in UCD format is present, APM will try to read a mesh in WRL format. The UCD and WRL formats support structured and unstructured elements. Check the corresponding section in the documentation for more information.
APM 1.0.8 (1 October 2023)
Added an extended_output option in the conf file. If the extended_output option is set to 1 each panel force and moment vector will be appended to the Paraview and Tecplot output files.
APM 1.0.7 (9 February 2023)
Added an x-z symmetry option to the APM solver. The symmetry option reduces the solution time and the required memory by a factor of 2. Check the corresponding section in the documentation for more information.
Added Trefftz plane analysis option for steady and unsteady simulations. Check the corresponding section in the documentation for more information.
Added a secondary APM executable where the solution is performed with double-precision floating point numbers. Note that for the same number of panels, the double-precision APM executable will require more memory.
Support for hybrid meshes - made up of quadrilateral and triangular panels.
Modified the body-to-wind transformation so CL, CD and CC follow the commonly adopted convention [1].
Various bug-fixes.
APM 1.0.6 (4 January 2022)
Added support for multiple wake-body intersections. E.g. intersections between a horizontal tail and a fuselage and a main wing and a fuselage.
Added a "mirror" option for each control surface. By default, the value of the mirror option is 1. A value of 1 will mirror the control surface across the x-z body-fixed frame. If mirroring is not required the value of the mirror option can be set to 0.
APM 1.0.5 (10 October 2021)
Further improved performance by parallelising any remaining "serial" for loops
Improved the panel neighbour search algorithm
Added a feature where a .vtu or .dat files are created if the trailing edge search algorithm fails. The files can be opened with ParaView or Tecplot and used for debugging.
Added a feature in the .stl file reader which rounds the coordinates in the file to the 6th digit after the decimal point
APM 1.0.4 (8 August 2021)
Improved performance by removing unnecessary copying
Removed the .res output format
Changed the integrated loads file format from .ires to .loads
Removed email and password authentication
Removed the .mesh file format.
Added a custom .stl file format that supports both structured and unstructured meshes.
APM 1.0.3 (9 May 2021)
Fixed bugs in the restart from checkpoint feature
Added a new authentication method (using a licence key). The authentication method uses an environmental variable "APM_KEY".
APM 1.0.2 (27 May 2020)
Fixed bugs in .conf file reader and in the JSON file writer
APM 1.0.1 (17 April 2020)
Added a .json output format. JSON results can be viewed in the APM Viewer available at https://apm.aviumtechnologies.com/viewer
Added a new method for pressure calculation (LSH) which uses inverse weighted distance interpolation and linear shape functions
Renamed the "high_order" option in the .conf file to "doublet_gradient_scheme". The doublet_gradient_scheme setting accepts the following values:
0 - the pressure is calculated with the CHTLS scheme
1 - the pressure is calculated with the WLS scheme
2 - the pressure is calculated with the LSH scheme
3 - the pressure is calculated with the FD scheme (the FD scheme can only be used for models with quadrilateral panels
APM 1.0.0 (30 October 2019)
Initial release
Testing new releases
Unit and integration testing is performed for each new APM release. Every portion of the software is tested - from influence calculation functions to gradient functions and helper functions. The solver and preprocessor are also tested by running a series of simulations (test cases).
References
[1] Brian L. Stevens and Frank L. Lewis. "Aircraft control and simulation / Brian L. Stevens, Frank L. Lewis," Wiley, New York 1992.
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