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Determination of the source term disturbing bounded flow performing practical Large Eddy Simulations

Krabben, I.G.W. (2020) Determination of the source term disturbing bounded flow performing practical Large Eddy Simulations.

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Abstract:Orifices are often applied noise sources in water pipes. These components disturb internal fluid locally which subsequently results in pipe wall vibrations in the system. In the extreme ultraviolet machines ASML produces, these vibrations lead to end-product inaccuracies. To model the expected flow-induced vibration, an accurate description of the source term is required. The source term is a fluctuating body force and is calculated using Large Eddy simulations (LES). A good match with Direct Numerical Simulations (DNS) pipe flow profiles is obtained for the flow statistics. Additionally, the power spectral density (PSD) of wall pressure fluctuations in a straight pipe agrees with experimental data. After the straight pipe flow is properly resolved, an orifice is added to the straight pipes. A comparison of a DNS one-dimensional energy spectrum with LES on the finest grid shows a good match in the inertial subrange. This indicates properly resolved turbulent scales. The PSD of wall pressure fluctuations in the orifice and upstream of the orifice show a similar shape compared to the simulated force spectra acting on the fluid. The slope of the force spectrum obtained with LES on the finest considered grid is the same as found in literature.
Item Type:Essay (Master)
Faculty:ET: Engineering Technology
Subject:52 mechanical engineering
Programme:Mechanical Engineering MSc (60439)
Link to this item:http://purl.utwente.nl/essays/80695
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