This master’s thesis deals with the aerodynamic basics of branched subsurface cavity structures and the analytical calculation methods derived from them. Analytical calculation methods help with the pre-dimensioning of ventilation systems, with plausibility checks of numerical calculations and with all fluidic calculations for which approximations are sufficient. In contrast to analytical calculation methods, numerical calculation methods for fluid engineering problems are very time-consuming and require vast amounts of computational power. The software, hardware and working time required for this task cause high costs. Therefore, analytical calculation methods and the necessary understanding of the flow processes are of great practical relevance for an engineer. At the outset of this thesis, the fluidic fundamentals of underground cavity structures are examined and summarized. The most important fundamentals are explained and the corresponding analytical calculation methods are provided. Furthermore, effects of the weather currents such as meteorological influences or fans are discussed. The aim of this thesis is to utilize the fluidic principles and analytical calculation methods presented at the beginning of the thesis in a meaningful way by using the example of the Zentrum am Berg. The calculated pressure curves, the speed curves and, for fire situations, the temperature curves are graphically displayed and checked for plausibility. For the first calculations, a 100 m long pipe was chosen the cross-section of which is modelled as a railway tunnel at the Zentrum am Berg. For this pipe, pressure losses were calculated in two flow situations. The first situation is a calculation with constant parameters. Hence the air flow and the wall have the same temperature. The second situation is a fire case with a flow that has a temperature profile. The results of the two cases were compared to numerical calculations. In the end, the Zentrum am Berg was viewed as a whole system. The focus was on the structural resistance and on the special alignment of the Zentrum am Berg. Based on this, analytical calculations of the pressure losses were made and displayed graphically.
|Translated title of the contribution
|Aerodynamic basics for the ventilation of branched subsurface cavity structures
|25 Jun 2021
|Published - 2021
Bibliographical noteembargoed until null
- Zentrum am Berg