Computational Fluid Dynamics (CFD) means numerical modeling and computation of the behavior of fluids and gases. Fluid flow computation is particularly useful when we want to gain deeper understanding of certain phenomena, such as heat transfer from a component to another. Fluid flow computation is applied in various branches of industry, for example, in the process, energy, medical and marine industries, as well as at server centers, in demanding HVAC engineering and urban planning.
Fluid flow computation can be combined, for example, with FEM analyses of strength calculation to model a construction as an easy to understand 3D simulation. With CFD and FEM computations, problems can be localized in a virtual manner and the right solutions for solving problems can be found on the basis of the model without production breaks.
The benefits of the fluid flow and strength computation for product development and problem solving are indisputable. Reliable data can be obtained at a very early stage and practically all flow conditions can be calculated and simulated.
Some of the phenomena that can be examined are listed below:
- Heat transfer
- Pressure losses
- Flow disturbances
- Rotating equipment
- Risk assessments
- Wind loads
Modeling thermal radiation is one of the most common applications of fluid flow computation. It is also used a lot in product development, since a better understanding of flow phenomena reduces the need of prototypes and testing can be carried out with a few different options.
What is the advantage of fluid flow computation and when is it useful to apply CFD simulation in design?
Typically, it is beneficial to apply fluid flow computation when experimental testing is challenging, expensive or even impossible. Compared to physical testing, CFD is a quick and easy method for reliable identification of potential problem situations.
Fluid management can improve the performance and operation of a process. The most suitable alternatives can be identified already at the design stage avoiding possible problems during the implementation. In this way, fluid flow computation will pay itself back already at a very early stage. Alternative designs can be simulated selecting the best one for the final implementation.
Remarkable savings in the construction costs of a protective wall for explosive gas mixtures
Pinja was mandated by one of its customers to design a protective wall for guiding and limiting the flow of an explosive gas mixture in case of a leak.
The risk was that the gas mixture could be carried from an adjacent pipe bridge to a processing place of railway carriages where a coal-based product was heated with electric resistances reaching a surface temperature of approximately 400 to 450 degrees Celsius. It was difficult to define suitable initial data for dimensioning the protective wall – an under-dimensioned protective wall would not solve the problem and the costs of an over-dimensioned one would be remarkable.
Gas leak scenarios of explosive gas mixtures were modeled using fluid flow computation software that provided a clear solution model for the situation and initial data for the design of the protective wall. Vaporized gas spread with the wind and its concentration reduced when mixing with air. With fluid flow computation, it was possible to determine the levels that were acceptable regarding risk management as well as the dimensions of the protective wall.
Savings amounting to approximately 30–40% could be achieved in the construction costs of a concrete protective wall designed on the basis of a CFD model compared to the original cost estimate and plan without fluid flow modeling.