Numerical modeling and simulation of particulate fouling on structured heat transfer surfaces using multiphase Eulerian-Lagrangian LES
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Beschreibung
The application of structured heat transfer surfaces, such as dimples or ribs, increase the local turbulence and thus thermal mixing. This can improve the efficiency of heat exchangers or cooling systems significantly. However, structured surfaces are known to promote particulate fouling, hence the unwanted accumulation and deposition of suspended particles (e.g., silt, sludge or iron oxide).
The scope of this work is the development of a universal numerical CFD method for the prediction of particulate fouling, especially on dimpled surfaces. The proposed approach is based on a combination of the Lagrangian point-particle tracking for the description of the disperse phase (fouling particles), and spatially and temporally resolved large-eddy simulations for the calculation of the continuous phase (carrier fluid). This approach allows not only the evaluation of the reduced thermo-hydraulic efficiency due to particle deposition, but also the investigation of the interaction between turbulent flow structures and the particulate fouling. It can be shown that the usage of spherical dimples as surface structures is not only the optimal choice from a thermo-hydraulic point of view, but also favors a substantial reduction of particulate fouling.
Autor*in
Robert Kasper
Themen in »Numerical modeling and simulation of particulate fouling on structured heat transfer surfaces using multiphase Eulerian-Lagrangian LES«
Ablagerungsbildung Cross stress tensor Dehnungsgeschwindigkeitstensor Dellen Druckverlust Druckverlust Euler-Lagrange Eulerian-Lagrangian Fanning-Reibungsfaktor Filter kernel Filterkern Fouling Fouling resistance Foulingverminderung Gesamtwärmeübergangskoeffizient