Ship Propulsion in Extreme Seas - SeaPro
SeaPro is a KMB-type research project, sponsored by the Norwegian Research Council (75%) and Rolls-Royce Marine (25%). The project started January 2007, and shall conclude at the end of 2010. The total budget is NOK 15.2 million, shared approximately equally between NTNU and MARINTEK. The project is managed by NTNU, by professor Sverre Steen. Dr. Kourosh Koushan is the project manager at MARINTEK. This project is co-ordinated through the Rolls-Royce University Technology Centre “Performance in a Seaway”.
Objectives of the project
The objective of the project is to develop knowledge and tools for optimisation of ships and ship propulsion systems for operation in heavy sea conditions, with respect to safety, reliability and efficiency.
Provide the knowledge about propulsion hydrodynamics required to develop a control system that shall reduce the mechanical loads and increase the efficiency of propellers operating in extreme sea conditions.
Provide the knowledge about hydrodynamics loads on thruster propellers in off-design conditions and extreme sea that shall enable optimum hydrodynamic and mechanical design of azimuthing thrusters.
Develop a method for accurate calculation of added resistance and speed loss of a ship in a seaway, implemented in an easy-to-use computer program.
Provide guidelines for good ship design with respect to added resistance and speed loss in waves.
Provide knowledge of the feasibility and possible application areas of RANS-type seakeeping calculations
Design of ships and propulsion systems are currently based on analyses of the performance in calm water. The effects of waves and ship motions are mainly taken into account using crude safety factors. Increasing fuel costs, introduction of novel ship designs and propulsion systems, together with the strict safety requirements and increasingly demanding marine operations to be performed in the northern seas means that this is no longer sufficient. Scientifically sound methods to find loads and responses related to operation in heavy seas need to be established.
SeaPro focuses on four areas:
- Propulsion dynamics in waves
- Propellers operating in extreme off-design conditions
- Added resistance and speed loss of ships in heavy seas
- Use of viscous flow solvers in seakeeping
Propulsion dynamics in waves is about prediction of dynamic forces of propellers and thrusters in extreme seas. FPSOs and other types of offshore vessels have experienced downtime and operational problems due to failure of propulsion units, which again is due to dynamic loads in waves. The aim of the activity is to be able to understand the physics and predict the loads.
Propellers operating in extreme off-design conditions is a mainly experimental study of the flow and forces on propellers in conditions, like bollard and crash-back. Accurate prediction of these forces is crucial for dimensioning of propeller blades. The study is performed in co-operation with Chalmers, who is going to study this with CFD.
Added resistance and speed loss in heavy seas aims at the development of methods to predict the added resistance and speed loss in waves of ships. The speed loss is important for fuel consumption and for regularity in service.
Reynolds-Averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) is increasingly used in ship hydrodynamics. As computer power is increased, it becomes possible to study also seakeeping problems with these methods.
International Symposium on Marine Propulsors
To promote the international exchange of research results and ideas, the first in a series of international conferences on marine propulsors took place in Trondheim 22-24 of June 2009. The second symposium in this series took place in Hamburg 15-17 of June 2011. Full proceedings of both symposiums are found online on the permanent homepage of smp, see www.marinepropulsors.com
The following people are deeply involved in the project. Others also contribute.
Project Manager: Professor Sverre Steen
Project manager for MARINTEK activities in SeaPro: Dr. Kourosh Koushan
PhD student, working on Propellers in Extreme Off-design Conditions: Hamid Amini
PhD student, working on Added Resistance: Guo Bingjie
PhD student, working on simulation of ships in waves and prediction of speed loss: Chuang Zhenju
High speed video picture of a well-submerged propeller subject to ventilation.