Propeller-Hull Interaction Effects in Calm Water and Regular Head Waves
Doktorsavhandling, 2024
Traditionally, power prediction has been carried out for ships operating in calm water rather than more realistic environmental conditions. However, waves can play a crucial role on the ship performance at sea. The interactions between waves, hull and the propulsion system of a ship may significantly affect the ship motions, resistance, wake, speed and propeller/engine load in comparison to calm water operational conditions. Nonetheless, it is practically impossible to take all of the entailed interactions between different ship components into consideration within the process of power prediction in all possible operational and environmental conditions, hence a series of assumptions and simplifications are often introduced.
In this thesis, as a step towards the ship power prediction in more realistic environmental conditions, the propeller-hull interaction effects in a range of selective operational conditions in calm water and regular head waves are considered in model-scale. The main objective is to perform numerical investigations of the ship performance in these conditions, aiming at understanding the involved flow physics in the propeller-hull interaction effects on the ship behavior and its propulsion characteristics. The investigations in both calm water and regular head waves are carried out in three distinctive steps: only the bare hull consideration, only the propeller consideration known as propeller open water (POW) and finally, for the self-propelled hull. The bare hull investigations incorporate employing two computational methods: a Fully Nonlinear Potential Flow (FNPF) panel method and a state-of-the-art Computational Fluid Dynamics (CFD) method using a Reynolds-Averaged Navier-Stokes (RANS) approach. However, for the POW and self-propulsion studies only the RANS approach is employed. A formal verification and validation (V&V) procedure is applied to understand and control the numerical and modeling errors in the RANS computations.
Overall, the results of the employed numerical methods were in good agreement with the experimental data. The analysis of the results provided valuable insight into the ship and propeller hydrodynamic performance in terms of the ship motions, resistance, wake, propeller characteristics and the correlations between them. The ship hydrodynamics analyses from this thesis can shed more light onto the propeller-hull interaction effects in waves and help the ship/propeller designers optimize their designs for more realistic conditions than only calm water.
RANS
Resistance
Thrust Deduction Factor
Self-Propulsion Point of Model
CFD
Regular Head Waves
Nominal Wake
Ship Motions
Taylor Wake Fraction
Propeller Open Water Characteristics
EFD
FNPF
Författare
Mohsen Irannezhad
Chalmers, Mekanik och maritima vetenskaper, Marin teknik
Investigation of ship responses in regular head waves through a Fully Nonlinear Potential Flow approach
Ocean Engineering,; Vol. 246(2022)
Artikel i vetenskaplig tidskrift
Towards Uncertainty Analysis of CFD Simulation of Ship Responses in Regular Head Waves
Proceedings of the 23rd Numerical Towing Tank Symposium, NuTTS 2021,; (2021)
Övrigt konferensbidrag
Comprehensive computational analysis of the impact of regular head waves on ship bare hull performance
Ocean Engineering,; Vol. 228(2023)
Artikel i vetenskaplig tidskrift
Irannezhad, M., Kjellberg, M., Bensow, R. E., and Eslamdoost, A., Experimental and Numerical Investigations of Propeller Open Water Characteristics in Calm Water and Regular Head Waves
Irannezhad, M., Kjellberg, M., Bensow, R. E., and Eslamdoost, A., Impacts of Regular Head Waves on Thrust Deduction at Model Self-Propulsion Point
Low Energy and Near to Zero Emissions Ships (LeanShips)
Europeiska kommissionen (EU) (EC/H2020/636146), 2015-05-01 -- 2019-04-30.
Propeller-skrov interaktionseffekter i vågor - del 2
Trafikverket, 2021-05-01 -- 2023-10-31.
Propeller-skrov interaktionseffekter i vågor
Trafikverket, 2019-05-01 -- 2021-04-30.
Drivkrafter
Hållbar utveckling
Styrkeområden
Transport
Ämneskategorier
Infrastrukturteknik
Strömningsmekanik och akustik
Marin teknik
Infrastruktur
C3SE (Chalmers Centre for Computational Science and Engineering)
ISBN
978-91-8103-004-4
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5462
Utgivare
Chalmers
HA4, Hörsalsvägen 4, Göteborg
Opponent: Professor Bettar el-Moctar, University of Duisburg-Essen, Germany