A5085940265- Ship Hydrodynamics and Maneuverability
- Maritime Transport Emissions and Efficiency
- Aerodynamics and Fluid Dynamics Research
- Spacecraft and Cryogenic Technologies
- Computational Fluid Dynamics and Aerodynamics
- Vehicle emissions and performance
- Aerospace Engineering and Energy Systems
- Fluid Dynamics and Vibration Analysis
- Advanced Aircraft Design and Technologies
- Advanced Combustion Engine Technologies
- Engineering Applied Research
- Fluid Dynamics Simulations and Interactions
- Hydraulic and Pneumatic Systems
- Advanced Numerical Methods in Computational Mathematics
- Cavitation Phenomena in Pumps
- Wind and Air Flow Studies
- Structural Integrity and Reliability Analysis
- Generational Differences and Trends
- Vehicle Dynamics and Control Systems
- Model Reduction and Neural Networks
- Advanced Multi-Objective Optimization Algorithms
- Rocket and propulsion systems research
- Electric and Hybrid Vehicle Technologies
- Mechanical Engineering and Vibrations Research
- Marine Biology and Environmental Chemistry
RISE Research Institutes of Sweden
2023-2025
SSPA (Sweden)
2019-2023
Chalmers University of Technology
2007-2023
California Maritime Academy
2023
The University of Tokyo
2015
Wind-powered ship propulsion (WPSP) is the concept where wind main source of thrust, while traditional system operates when needed. This type can lead to considerably reduced emissions, something that shipping community striving for. A well-known example WPSP Oceanbird with goal cut emissions up 90%. In this study, propeller design process for a wind-powered car-carrier (wPCC) such as investigated, what various challenges are and therefore how an automated optimisation procedure should be...
This paper discusses the impact of scaling effects in performance a standalone wing sail, comparing experiments and numerical simulations. The experimental data sail with NACA0015 section, tested R.J. Mitchell wind tunnel at University Southampton, are compared tests run KTH Royal Institute Technology, where L2000 had smaller scale, Computational Fluid Dynamics simulations three different cases. For simulations, first model scale Southampton was simulated. Then, keeping same domain...
Wind propulsion for commercial cargo ships is rapidly emerging as a viable technology to reduce greenhouse gas emissions. Naval architects frequently adapt methods and tools originally designed sailing yachts create these modern "sailing" vessels. Typically, steady-state Performance Prediction Programs (PPPs) are used estimate vessel speed, leeway, heel, other factors under various wind conditions. However, do not account dynamic such unsteady sail forces due ship motions in waves, gusty...
International shipping plays a vital role in the world's transport system and economy. However, faces challenges terms of reducing its environmental health impact, namely emission greenhouse gases, air pollutants, chemical substances to marine environment. In particular, roughness condition underwater surfaces ship hull affects ship's energy efficiency, with growth (biofouling) mechanical leading propulsion powering penalties. Measures control biofouling, using antifouling coatings in-water...
Installing an energy saving device such as a pre-swirl duct (PSD) is major investment for ship owner and prior to order reliable prediction of the savings required. Currently there no standard how be carried out, possible alternatives are both model-scale tests in towing tanks with associated scaling procedures, well methods based on computational fluid dynamics (CFD). This paper summarizes CFD benchmark study comparing industrial state-of-the-art ship-scale predictions power reduction...
The 1978 ITTC Power Prediction method is used to predict the propulsive power of ships through towing tank testing. form factor approach and its determination in this have been questioned. This paper investigates possibility improve predictions by introducing Combined CFD/EFD Method where experimental replaced double body RANS computations applied for open cases KVLCC2 KCS, including first-time published tests at ballast condition an uncertainty analysis specifically derived factor....
Predicting the propulsive power of ships with high accuracy still remains a challenge. Well established practices in 1978 ITTC Power Prediction method have been questioned such as form factor approach and its determination method. This paper investigates possibility to improve predictions by introduction combined CFD/EFD Method where experimental is replaced double body RANS computations. Following Quality Assurance Procedure proposed ITTC, best practice guideline has derived for CFD based...
Shipping is vital for global trade but also emits significant greenhouse gases. To address this issue, various measures have been proposed, including improved ship design, alternative fuels, and operational practices. One such cost-effective measure trim optimisation, which involves operating the at hydrodynamically optimal forward aft draughts. This study focuses on investigating trends of a RoPax vessel using experimental fluid dynamics (EFD) computational (CFD) methods. The are derived in...
Rapid performance prediction tools are required for the evaluation, optimization, and comparison of different wind propulsion systems (WPSs). These should capture viscous aerodynamic flow effects in 3D, particularly maximum force, stall angles, interaction between lift-generating units. This paper presents a rapid calculation method wing sails that combines semi-empirical lifting line model with potential flow-based to account 3D effects. The was applied WPS consisted several considerable...
Verification and Validation of CFD simulations delivered power at full-scale are carried out for a single screw cargo vessel. Numerical performed with steady-state RANS method coupled body force propeller model based on lifting line theory. There no significant differences in the uncertainty levels between computations. The finest grid exhibits numerical 1.40% full-scale. Computed results compared sea trial data three sister ships. Special attention is paid to effect roughness hull...
International regulations on greenhouse gas (GHG) emissions as well strong market demand for zero-emission transport calls a radical change in the shipping industry. Measures such hull form optimization, use of alternative fuels and efficient machinery systems, new coatings, smart routing have already improved energy efficiency world fleet to some extent its GHG emissions. However, it is far from enough. To make drastic leap that we need order meet climate challenges, must turn emission-free...
With environmental concerns becoming one of the most important issues facing shipping/ship-building industry today, SSPA Sweden AB has witnessed strong demand for development energy saving devices (ESD). anticipates that will be greater to respond new requirements set by International Maritime Organization (IMO) regulation on efficient design index (EEDI). been involved in many joint research projects developing solutions. Daewoo Shipbuilding and Marine Engineering Co. Ltd. (DSME) developed...
Determining a ship's propulsive power is critical stage in the design phase which evaluation of stern plays crucial role. Different flow regimes can be observed depending on position and shape transom. This paper investigates wetted-transom characteristics their implications 1978 ITTC Performance Prediction Method. In case separation, such as flow, current ITTC-78 procedure does not provide an alternative method. Therefore, two methods were proposed based investigations CFD computations...
Unexpected low value of the relative rotative efficiency ηR is sometimes noted when scaling towing tank model-test result with ITTC-78 method to obtain propulsive factors propellers. The paper explains causes this phenomenon. boundary layer state three propellers was studied by a paint test and RANS method. tests showed that in behind conditions at Reynolds number (Rn) are covered mainly laminar flow, which different from open water conducted high Rn. Apart moderate difference Rn between...
Abstract. For a sailing yacht, depowering is set of strategies used to limit the sail force magnitude by intentionally moving away from point maximum forward driving force, potentially reducing ship speed. The reasons for doing this includes among others; reduction quasi-static heeling angle, structural integrity masts and sails crew comfort. wind powered cargo ship, time spent on route utmost importance. This leads question whether there performance difference between different if so, how...
This paper deals with several aspects of surface roughness modelling in RANS codes applied to full-scale ship simulations. To select a method that is suitable for wall-resolved solvers and gives reliable results at high Reynolds numbers, five different models are compared. A grid uncertainty analysis performed the sensitivity resolution close wall (y+) investigated. The compared extrapolated experiments carried out rough plates various heights types. correlation factor between Average Hull...
The need to reduce green-house gas emissions from shipping has reborn the interest in wind propulsion for commercial cargo vessels. This places new requirements on tools used ship design, as well methods usually applied sailing yacht design. A range of design are by designers at various stages wind-assisted ships and different purposes. One important tool is steady-state velocity prediction program (VPP) which typically predict speed vessel when a directions speeds. Steady-state VPPs can be...
Accurate performance prediction is necessary when designing/optimising wind propulsion systems (WPS). An independent, trustworthy of the energy-saving potential also needed to support ship owner’s decision invest in new technology. By using weather statistics along with a mathematical model performance, route simulations can estimate time and power required for transit route. Such are commonly used today optimise design operation conventional ships. The introduction WPS poses additional...
A wind tunnel test of an America's Cup keel model is used for validation one Reynolds-averaged Navier Stokes (RANS) code and potential flow/boundary layer code. The effects grid size, stagnation point anomaly, turbulence on the RANS results are discussed. Various setups compared. ability both methods to predict forces trends shown. errors slightly larger than experimental error, whereas within uncertainty, provided that a correct panelization used. comparison wake flow pattern computed with...
An efficient numerical method is proposed to estimate delivered power and speed loss for a ship in wind waves. The added resistance waves, obtained with an unsteady potential flow panel method, the calm water from steady-state flow/RANS coupled body force propeller model self-propulsion. A comparison of experimental results made resistance, power. good agreement obtained. As practical application, approach used calculate weather factor, fw, Energy Efficiency Design Index (EEDI). calculated...
Before the background of International Maritime Organization’s 2050 emission reduction targets, largest sailing ship in world is currently being developed Sweden This wind powered car carrier, called Oceanbird, will have four 80-metre-high wing sails targeting CO2 savings order 90%. The prediction and analysis seakeeping performance such a importance, not only terms dynamics, but also when it comes to structural design rig. To this end, numerical method for predicting ship’s motions loads...