Turbulence modelling capabilities of ILES for propeller induced URN prediction

Publikationstyp
Conference Paper
Date Issued
2020-09
Sprache
English
Author(s)
Kimmerl, Julian  
Mertes, Paul  
Abdel-Maksoud, Moustafa  orcid-logo
Institut
Fluiddynamik und Schiffstheorie M-8  
TORE-URI
http://hdl.handle.net/11420/8119
Citation
SNAME Maritime Convention, SMC: (2020-09)
Contribution to Conference
SNAME Maritime Convention 2020, SMC 2020  
Scopus ID
2-s2.0-85096527412
Over the last decades underwater radiated noise due to human shipping activities increased significantly, which has proven adverse effects on the perception of fish and marine mammals. To protect and preserve marine biology, regulations regarding acoustic emissions of ships and specifically underwater radiated noise, are continuing to be tightened by regulatory institutions. This development is urging the shipbuilding industry to improve sound prediction and analysis methods. With the propeller as the dominating acoustic source under water, in particular propulsion solution manufacturers need to act in order to meet future requirements not only for near field acoustics, which are primarily studied as pressure pulses on the ship hull, but also far field sound propagation. CFD simulations allowing for scale resolved turbulence modelling and phase-transition are required to identify acoustic sources, which are usually accompanied by immense numerical resource demands. With an implicit Large Eddy Simulation (ILES) turbulence modelling approach a numerically relatively efficient and thus industry friendly way of resolving turbulent length scales is pursued and combined with the Schnerr-Sauer mass transfer model for cavitation simulation. The simulation method is benchmarked for hydrofoils, open water propeller tests and a propeller in behind ship condition, to evaluate the proposed setups accuracy of predicting turbulent flow structures and cavitation inception and extent, with the intention of ultimately confirming acoustic signatures in the near field. While tip vortex and cavitation structures are investigated for instance for the Arndt hydrofoil and the PPTC’11 test case, acoustics are analyzed with the Newcastle propeller test case, which leads to good agreement with experimental results reinforcing this approaches capabilities.
Subjects
CFD
Implicit LES
Propeller cavitation
Tip vortex
Turbulence
Underwater radiated noise