Examination of an airflow around tall building and bridge structure

HPC-Competence Center

Poznan Supercomputing and Networking Centre (PSNC) is the leading research and computing centre in Poland. PSNC provides access to quality production environment for advanced computations and data processing. HPC resources located at PSNC include specialized computing systems with different architectures: multiprocessor SMPs, tightly coupled clusters and GPGPU machines. PSNC has increased the availability of cloud computing and HPC tools, in the form of dedicated applications, web platforms, and by offering new services for optimizing time and costs of calculations carried out remotely by various partners, including SMEs.

The Enterprise

SOFiSTiK is a software company focusing in the area of structural and mechanical engineering. SOFiSTiK offers state-of-the-art software tools for structural engineering and CFD calculations, as well as fluid-structure interaction problems and energy-related design optimizations of structures and mechanical components. It works intensively together with leading software companies in Germany and acknowledged Greek experts, including Technical Universities and R&D teams. With a portfolio of about 400 customers it belongs to the most prominent engineering consulting offices in Greece, and is among the first 50 in South and East Europe. SOFiSTiK also cooperates closely with other partner companies in Germany that offer structural analysis software worldwide and have an installed base of at least 5.000 desktop systems.

How HPC makes the difference

Numerical analysis of bridge structure stress is a complex task for engineers at the design stage. Regarding the need of analysis of structure strength, it is not enough to perform just structural analysis. It has also to be taken into account that wind is the key factor in stress applications. A dramatic example of devastating influence of wind load interacting with bridge structure response was the collapse of Tacoma Narrows bridge in 1940.

Airflow streamlines behind tall building

Figure1: Airflow streamlines behind tall building

Today, it is clear that at the stage of bridge design metaphysics approach must be applied when analysing the structure. From a computational point of view, the simulation of the wind load is the most demanding part of computations, as it requires the usage of a parallel solver to produce results in reasonable time. Therefore, thanks to HPC technologies much bigger engineering problems, in advanced bridge structure constructions, can be analysed and optimized. An example of proper numerical solver dedicated to the analysis of wind loads of bridge structures is an application developed by SOFiSTIK. The example application is designed to examine wind effects on buildings structures through various weather scenarios.

This solution is widely used in civil engineering with its main applications being:

  1. examination of the airflow around buildings,
  2. natural ventilation systems design and
  3. simulations of fire events in tunnels.
Airflow streamlines around bridge segment

Figure2: Airflow streamlines around bridge segment

The application resolves governing equations with finite volume method and allows performing various simulations of incompressible 2- and 3-dimensional fluid flows. It is able to run both steady and unsteady simulations of internal and external flows using laminar or turbulent approach, with possibility of taking into account full coupling and interaction of wind and solid structure. The code also provides resolving of heat transfer and buoyancy effects.

At PSNC, the application was used to simulate airflow around one segment of bridge structure and also an airflow around a tall building using k-ω-SST turbulence model in both analyses. All the computations were performed at PSNC Eagle and Inula clusters. Each computational domain was partitioned and around 100 and 60 CPU cores respectively were used. Exemplary results are presented in Figure 1 and Figure 2.