CFD comfort and flow simulation

Computational Fluid Dynamics (short: CFD) deal with the numerical investigation of currents. CFD flows are a practical alternative to experimental experiments like wind tunnel tests. Flow simulations enable investigations of flows, internal flows of buildings, water taps and heat flows. CFD programmes offer a numerical approximation by using the differential equations with a system of algebraic approximate equations. As discretisation methods we apply finite differences, finite elements and finite volume methods by using the approved Autodesk software programme.

The following results can be achieved by flow simulations:

• Minimisation of draft risk
• Improvement of thermal comfort
• Checking of the effectiveness of ventilation concepts
• Calculation of flow velocities
• Determination of building aerodynamics

Our range of services regarding noise simulation includes investigations in the context of planning traffic routes, noise remediation, land use planning (ÖNORM B8115, OIB 5 guideline), approval of industrial and sports facilities (ÖAL guidelines), noise maps and noise action plans. In this area, we create simulations with the Soundplan software. You can find further information on this topic under “noise protection”.

With a thermodynamic simulation, the factors of an energy concept can be quantified in detail. All important thermodynamic effects can be replicated by calculation models using software from TRNSYS. Thus, it is possible to predict reliably in high temporal resolution temperatures, comfort limits and energy flows. The simulation can also take into account the building technology systems, such as chilled ceilings (TAB), ventilation, humidification and dehumidification and radiators. This is how weak points are identified and the overall system can be optimised in advance.

When simulating the thermal bridges, two- and three-dimensional surface temperatures and isothermal calculations are created. These are mainly used with:

• Increased heating requirements
• Defrost water failure
• Mold infestation

In general, a distinction is made between material-related (especially use of building materials with high thermal conductivity) and geometric (for example, if the inside and outside surfaces are unequal – especially on house corners, dormer windows or bay windows) thermal bridges. For the simulations we use software from buildingsphysic.com.

CFD programmes are also used for wind load simulations. They offer practical numerical approximation solutions by approximating the differential equations with a system of algebraic equations. Again, we apply discretisation methods for finite differences, finite elements and finite volume method. This way, envelope surfaces – for example for halls with different variant studies – can be examined for wind loads. Also, comprehensive information for the statics on the envelope surface are determined in this manner. Special examinations of gusts and turbulence resulting from this can be developed as well. The results of the simulation on the one hand make statements about the air velocities (m / s), on the other hand they determine the pressure distributions on the envelope surface. We also use the Autodesk software in this area.

Any questions? We are happy to help you – feel free to reach out to our team in Vienna!