News

• The particle-wall contact model and algorithm are deeply modified and updated, which greatly enhances the stability of the solver, especially in dealing with the contact between particles and extremely slender triangular meshes of device with complex geometry. There are still some defects in the contact model and algorithm of DEMSLab 3.0, which leads to frequent error reporting. DEMSLab 4.0 completely solves this problem.

• DEMSLab 4.0 supports the import of various STL formats, including text format and binary format. In addition, it supports the import of multiple STL files. The maximum number of simultaneous import files is 1000, which makes any complex geometries generated by 3D modeling software can be imported directly.

• The Hertz Mindlin model and the new linear model are added. Two kind of linear models as the basic linear model and the general linear model are provided by DEMSLab 4.0 to meet the different needs of users.

• An adaptive time step solver is added, which can automatically calculate the optimal time step without any time step information set by users. There are four options in the adaptive time step solver: fast + +, fast +, fast, robust, among which fast + + is the fastest and robust is the most stable. The fastest adaptive time step option (fast + +) can solve more than one time faster than the fastest fixed time step.

• The DEM-CFD coupling algorithm is improved to make the shared memory file smaller. At the same time, DEMSLab 4.0 supports coupling with nearly any serial and parallel version of ANSYS Fluent (from 12.0 to 19.0).

• All-new and more modern and easy-to-use operation interface, including menu bar, shortcut key, view area, output pane, progress bar, etc., enhances the interaction with users and is more convenient to use.

• Clear the problem that the User C function name of initial overlap cannot be saved.

• The User C function and interface of setting initial overlap between particle and wall are added.

• The maximum number of parallel threads increased from 100 to 1000.

• Fixed the code for device out of computational field.

• Improved the import of STL file in Polyhedron dialog box, Multi-sphere dialog box, Bounded-sphere dialog box, and Matrix Manager dialog box. The extension of the file can be STL or TXT, and the type can be ASCII or binary file.

• The unit conversion function of imported STL file in Matrix Manager dialog box is added.

• The Autosave dialog box and the Transient Data dialog box have been modified to make them have the function of output by time interval.

• The accuracy of particle number in dynamic creation is improved.

• Many bugs about interface and file output are solved.

• This version was released on August 15, 2020.