Success Story: Using bulk simulation in the development of a railway freight car

NCC presenting the success story

The Czech National Competence Centre (NCC) for High-Performance Computing (HPC) and Data Analysis (HPDA) is represented by IT4Innovations National Supercomputing Center at VSB – Technical University of Ostrava. Its mission is to analyse, implement, and coordinate all the activities required to offer end users the services they need: from access to supercomputers and technology consulting to providing training for industry, public administration, and academia.

Industrial Organisations Involved:

Advanced Engineering is a well-established Czech technology and engineering company that focuses on computer simulations, structural analysis and optimisation of structures, and multi-physics modelling and simulation. More info:

Technical/scientific Challenge:

Advanced Engineering carried out a pilot project to simulate the emptying of a newly developed truck; a 103 m³ Tagnpps model designed primarily for grain transport. Because clients expected a guarantee for the time required to empty each wagon during unloading, the development team needed to assure that the designed geometry of the bins and hoppers would ensure complete emptying, without grain sticking to the walls. Knowing the force conditions during emptying, i.e. the action of the grain flow, helped to properly size the closing mechanisms so that the opening and closing forces were suitable for the operator.


CAE specialists at Advanced Engineering used the Altair EDEM software tool (, a leading Discrete Element Method (DEM) simulation solution, for computer simulations of bulk material. The particular problem for the freight car was the dimensions given by the ratio of the cargo space and the particle size; in other words, the number of elements representing grains, which for such a problem is in the order of millions.

For each element and each time step, the DEM calculates the interactions of the particles with respect to each other and the environment, and thus calculates the positions of the elements for the next step. In summary, we get a simulation of the grain discharge stream and can observe how each layer of the fill empties, which locations empty first, which empty last, and why. To solve such a problem in a reasonable time, HPC infrastructure is required.

Business impact:

The advantage of computer simulations of bulk material movement compared to physical testing is that the cost of renting the testing space (in our case a grain silo) and the cost of the test fill (grain) are eliminated. An added benefit is the ability to simulate the interaction of the bulk material with the structure, the ability to compare multiple design options, and to more easily analyse the behaviour of different types of materials (grain) under different external conditions (temperature, moisture).

From the user’s point of view, it is important to find out what the real-time requirements for such simulations are, and of course, what costs would have to be considered for further simulations.

From an Advanced Engineering perspective, it was important for the Altair EDEM simulation tool to know where the so-called “performance breaks” were, i.e. how many processors are required to maximise the efficiency of both speed and cost of computation. The second task was to compare the performance and cost-effectiveness of computations on standard (CPU) or graphics processing units (GPU).


  • Time and costs savings through numerical modelling and simulations;
  • the ability to simulate the interaction of the bulk material with the structure;
  • the ability to compare multiple design options and to more easily analyse the behaviour of different types of grain materials under different external conditions (temperature, moisture).


  • Keywords: Discrete Element Method (DEM), High-Performance Computing (HPC)
  • Industry sector: Railway industry
  • Technology: HPC, Discrete Element Method (DEM)

Ongoing simulation of emptying a freight wagon box – one-quarter simulation model.

Calculations of the frictional and normal force from the flowing bulk material (grain) on the hopper closing mechanism.


Tomas Karasek (

This project has received funding from the European High-Performance Computing Joint Undertaking (JU) under grant agreement No 951732. The JU receives support from the European Union’s Horizon 2020 research and innovation program and Germany, Bulgaria, Austria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Greece, Hungary, Ireland, Italy, Lithuania, Latvia, Poland, Portugal, Romania, Slovenia, Spain, Sweden, the United Kingdom, France, the Netherlands, Belgium, Luxembourg, Slovakia, Norway, Switzerland, Turkey, Republic of North Macedonia, Iceland, Montenegro