Rocky DEM 4.4 Release: Reinventing Solver Customization

Written By: 
Rocky DEM

Rocky DEM 4.4 delivers a totally new Solver Application Programming Interface (Solver API) based on the most-recent technology for customization and user experience integration. The result delivers unique usability, portability and, above all, solver performance.

What’s different in Rocky DEM 4.4’s Solver API?

User experience

All models implemented with the Solver API also modify and extend the setup and post-processing software interface. In the setup stage, to enter custom model input parameters, the software dynamically generates a visual interface; in the post-processing stage, all new custom variables are automatically available for detailed analysis. This enables seamless deployment of custom models built by experts, all across the corporation.

A single code for both multi-CPU & multi-GPU solvers

The Solver API provides a unified approach so users can program models by enabling just one single code to be compatible with both Rocky DEM solver technologies. This substantially reduces the cost involved in maintaining custom routines or learning complex GPU programming techniques.User writes one C++ code and compiles for both multi-CPU and multi-GPU solvers
obtaining a native execution on both Windows and Linux OS.

No performance degradation

Custom models implemented using the Solver API run as fast as original embedded models. Rocky DEM provides a true application programming interface, and not just a “set of function hooks”. Users can implement their own models using the same structure and logics from embedded models, all without code virtualization or memory overhead.

We wanted to deliver something innovative. We did not want our users to experience poor performance or miss out on any features. And worst-case, we did not want our customers to have to rewrite their code because they were now using the multi-GPU solver.

Marcos Cabral Damiani, Platform Development Manager at ESSS

The new Solver API in Rocky DEM 4.4 is C++ based, and it enables many new physics to be implemented — such as new contact and joint models, particle properties, body forces, and custom scalars. 

Charged particles coupled with Ansys Maxwell simulation for 2 magnets in an on/off scenario.

In the tablet coating process, tablet mixing, spraying and drying happen simultaneously and impact the final product quality. The Rocky DEM smart API provides capability to couple air flow, the heating and drying model, and tablet motion to capture the complex physics in the coater.

Gopal Kasat, Project Manager from Tridiagonal Solutions



Rocky DEM and Ansys CFD integration to study the drying process in a tablet coater using custom heat and mass transfer models.

Other Rocky DEM 4.4 new functionalities include a custom particle input, the ability to freeze elements, and a user definition of center of mass and moment of inertia, with a focus on solid particles with complex shapes and high aspect ratios. Also, a new cylindrical periodic boundary condition is included as well as several other improvements.

Vacuum cleaner and carpet model using Ansys CFD and Rocky DEM integration.
Custom fiber model and grounded elements implemented using solver API.

By adding our new C++ Solver API together with the existing Python-based API for workflow automation, Rocky DEM 4.4 redefines what API means by delivering best-in-class functionality to customers who need flexibility without compromising performance.

For more information, please join our Rocky DEM 4.4 launching event below, or visit





  • I would like to hereby express my vote of confidence in Qfinsoft, in their ability to service and provide a strong support to us as a company.  We have been a customer of Qfinsoft for over a year and I am pleased to compliment them on their impeccable service offered to us thus far

    - Nico Gunther, Powertech Transformers

  • Since the introduction of ANSYS, more students are using first principles and FEA to validate their designs. This year, more than 60% of the projects were using FEA as a standard approach for numerical calculation. This number shows the huge impact ANSYS, had on University of Pretoria. FEA is not anymore a specialised tool for few users but a standard engineering tool easily integrated in the design process.

    - Francesco Pietra, University of Pretoria

  • For their consulting, training and technical support, Qfinsoft (Pty) Ltd must be the first choice of any firm looking for CAE experts

    - Prof G Akdogan, Process Engineering, University of Stellenbosch

  • At Aerospace, we have successfully used the ANSYS suite of tools to design high-performance gas turbine engines. Throughout this program, Qfinsoft provided valuable support and assistance to accelerate the development of our models. Their accessibility, short-turn around times and willingness to go beyond what is expected make them an effective partner on our projects. 

    - Dr. Hannes Pretorius

Our Clients