際際滷

際際滷Share a Scribd company logo

CFD_salesmaterial_261215

S
Stig Stagh淡j Knudsen

OSK-ShipTech A/S is a leading naval architecture company that uses computational fluid dynamics (CFD) to simulate complex hydrodynamics for clients. They have validated two CFD codes, Star-CCM+ and OpenFOAM, which they use to perform simulations like resistance prediction, bulb and hull optimization, and propeller simulations. These simulations provide accurate predictions to optimize designs and reduce fuel consumption and resistance.

1 of 12
Download to read offline
Computational Fluid Dynamics (CFD)
2 OSK-ShipTech A/S is one of the leading naval architect companies in Denmark. We cover several business areas, i.e. concept design, basic design, contractual services, project management, supervision and hydrodynamics. When simulating complex hydrodynamics for clients, OSK- ShipTech A/S combines more than 45 years of experience in the field of naval architecture with cutting-edge technology in CFD - Computational Fluid Dynamics Computational Fluid Dynamics Over the last decades, the use of CFD has grown rapidly as computational power has increased. In the marine industry, CFD is used for many applications including resistance prediction, bulb and hull optimisation, wind force prediction, exhaust simulations and internal flows. CFD is also used as a virtual towing tank for calculation on hulls and propellers, producing results with high accuracy. OSK-ShipTech A/S applies two validated and verified high performance CFD codes for simulation of fluid flow for various applications, namely Star-CCM+速 and OpenFOAM速 . These CFD codes have been extensively validated both by vendors and within OSK-ShipTech A/S in order to provide a high quality product to our clients.
3 Validation and Verification OSK-ShipTech A/S is highly committed to delivering the highest possible quality to our customers at all times. In order to ensure this level of quality, a large internal validation study has been carried out. The figure to the right illustrates the obtained accuracy of the virtual towing tank against the computational resources used. The validation study has provided us with unique knowledge and tuning of the CFD codes. The tuning of the codes provides higher accuracy in less time. OSK-ShipTech A/S continues to extend the validation database, and the solutions of each project are carefully verified to secure the highest accuracy. High speed vessel
4 Resistance and Self-Propulsion Resistance and propulsive efficiency are important parts of the hydrodynamic performance of a vessel. Knowledge of resistance and propulsive performance is therefore essential in the early design phase in order to secure the final efficiency of the vessel. OSK-ShipTech A/S virtual towing tank resistance and self-propulsion tests are performed similarly to conventional model tests. However, simulations are full scale contrary to tank model test with unwanted scale. OSK-ShipTech A/S virtual towing tank test provides: Fast turnaround time in design phase Accurate predictions of resistance and propulsive performance Accurate trim and heave predictions Detailed flow field for hydrodynamic performance evaluation
5 Trim Optimisation A simple way to save fuel is to trim the ship to its optimum. OSK-ShipTech A/S cooperates with providers of state-of-the-art trimming support software applicable to all kinds of ships. The software is based on tailor-made high-end CFD calculations made by experienced engineers from OSK-ShipTech A/S. Feedback from previous clients concludes: 2% fuel saving is easily obtained and possibly more Excellent correlation between CFD predictions and measured full scale performance Short return of investment Courtesy of Marine Alignment Fuelsaver interface
6 Optimised (Resistance decreased 15 %) Baseline Design Stage Optimisation OSK-ShipTech A/S uses a parametric optimisation framework (FRIENDSHIP-Framework速 ) for optimisation of various marine applications. The process of optimising a complex surface has been developed by OSK-ShipTech A/S and is automated by an interaction between a CFD code (STAR-CCM+速 or OpenFOAM速 ) and the optimisation algorithm controlling the change of hull form. This results in a hull form that is perfectly adapted to fulfil the optimisation goal within the prescribed limitations. Hull Optimisations Hull optimisation improves the efficiency of the vessel by changing the hull form in order to reduce the generated waves and thereby the energy used for propulsion. Optimisation of the hull form can lead to significant improvements in resistance and hence large fuel savings. Bulb and aft ship hull form optimisation or new building projects are carried out over a range of operation conditions in order to cover the operational profile of the vessel. Baseline Optimised (Resistance decreased 15 %)
7 Retrofit Optimisation Increased fuel prices force some ships to transit at lower speeds than design speed (slow steaming), and considering a retrofit for the bulbous bow or aft ship might be beneficial. Having the experience and technical skills, OSK-ShipTech A/S is able to help our clients and assist the owner in deciding the optimal retrofit for each vessel and tailoring the right solution offering an attractive return of investment. Example of Retrofit: Bulb Optimisation The bulbous bow highly influences the resistance of the vessel. If the vessel is not operating at the speed and draft it was originally designed for, a new bulbous bow can prove to be a very good investment. For a bulbous bow to be successful, the shape has to be optimised to the operational profile in order to minimise fuel consumption over the range of conditions. Within bulb optimisation, OSK-ShipTech A/S offers: Reduction of hull resistance / savings on fuel consumption consistent with the operational profile Quick delivery of retrofit design including hydrodynamics and steel design
8 Propeller Simulation One of the big challenges in marine CFD is modelling the flow past propellers. OSK-ShipTech A/S has focused a great deal on this issue and is able to deliver trustworthy results tailored to each project. Optimisation of the propulsion unit has a direct impact on the overall efficiency of the vessel. Optimisation of the propellers provided by OSK-ShipTech A/S can lead to the following improvements: Increased overall efficiency of the vessel / reduced fuel consumption Reduction of cavitation Reduction of noise and vibrations
9 Manoeuvring Abilities A CFD analysis can be a powerful and cost-effective tool for prediction of the manoeuvring abilities of ships. In contrast to tank tests in model scale, OSK-ShipTech A/S calculates the manoeuvring abilities in full scale using high-end CFD calculations. These calculations make it possible to predict the compliance with e.g. IMO Resolution MSC.137(76) as early as design stage after which any needed suggestions for improvements will be provided by OSK-ShipTech A/S. With manoeuvring calculation from OSK-ShipTech A/S, the ship can confidently sail on its full scale sea trial. Examples of simulations: Turning circle Zig-Zag test Course keeping Wave elevation during Zig-Zag test Turning circle test
10 Environmental Forces Marine applications are exposed to powerful forces of nature and very often, conceptual and structural design is based on the exposure to these forces. Accurate estimation of the forces of nature may be the key to success of a given project. OSK-ShipTech A/S is able to provide CFD simulations of: Wave forces: Regular waves - Irregular wave spectrums - Freak waves Wind forces Current forces CFD simulation for Dynamic Positioning (DP) Wave loads on a cylinder
11 Additional Applications OSK-Shiptech A/S has extensive experience in the use of CFD in a wide range of other fluid applications such as: Pipe flows Pump simulations Heat exchangers Sloshing tanks Offshore structures Ventilation systems Fire simulations High-speed vessels Catamarans Exhaust simulations Sail simulation and optimisation Azimuth propellers Wave loads on a lattice tower Simulation of a centrifugal pump Wake behind catamaran
CFD_salesmaterial_261215

More Related Content

CFD_salesmaterial_261215

  • 2. 2 OSK-ShipTech A/S is one of the leading naval architect companies in Denmark. We cover several business areas, i.e. concept design, basic design, contractual services, project management, supervision and hydrodynamics. When simulating complex hydrodynamics for clients, OSK- ShipTech A/S combines more than 45 years of experience in the field of naval architecture with cutting-edge technology in CFD - Computational Fluid Dynamics Computational Fluid Dynamics Over the last decades, the use of CFD has grown rapidly as computational power has increased. In the marine industry, CFD is used for many applications including resistance prediction, bulb and hull optimisation, wind force prediction, exhaust simulations and internal flows. CFD is also used as a virtual towing tank for calculation on hulls and propellers, producing results with high accuracy. OSK-ShipTech A/S applies two validated and verified high performance CFD codes for simulation of fluid flow for various applications, namely Star-CCM+速 and OpenFOAM速 . These CFD codes have been extensively validated both by vendors and within OSK-ShipTech A/S in order to provide a high quality product to our clients.
  • 3. 3 Validation and Verification OSK-ShipTech A/S is highly committed to delivering the highest possible quality to our customers at all times. In order to ensure this level of quality, a large internal validation study has been carried out. The figure to the right illustrates the obtained accuracy of the virtual towing tank against the computational resources used. The validation study has provided us with unique knowledge and tuning of the CFD codes. The tuning of the codes provides higher accuracy in less time. OSK-ShipTech A/S continues to extend the validation database, and the solutions of each project are carefully verified to secure the highest accuracy. High speed vessel
  • 4. 4 Resistance and Self-Propulsion Resistance and propulsive efficiency are important parts of the hydrodynamic performance of a vessel. Knowledge of resistance and propulsive performance is therefore essential in the early design phase in order to secure the final efficiency of the vessel. OSK-ShipTech A/S virtual towing tank resistance and self-propulsion tests are performed similarly to conventional model tests. However, simulations are full scale contrary to tank model test with unwanted scale. OSK-ShipTech A/S virtual towing tank test provides: Fast turnaround time in design phase Accurate predictions of resistance and propulsive performance Accurate trim and heave predictions Detailed flow field for hydrodynamic performance evaluation
  • 5. 5 Trim Optimisation A simple way to save fuel is to trim the ship to its optimum. OSK-ShipTech A/S cooperates with providers of state-of-the-art trimming support software applicable to all kinds of ships. The software is based on tailor-made high-end CFD calculations made by experienced engineers from OSK-ShipTech A/S. Feedback from previous clients concludes: 2% fuel saving is easily obtained and possibly more Excellent correlation between CFD predictions and measured full scale performance Short return of investment Courtesy of Marine Alignment Fuelsaver interface
  • 6. 6 Optimised (Resistance decreased 15 %) Baseline Design Stage Optimisation OSK-ShipTech A/S uses a parametric optimisation framework (FRIENDSHIP-Framework速 ) for optimisation of various marine applications. The process of optimising a complex surface has been developed by OSK-ShipTech A/S and is automated by an interaction between a CFD code (STAR-CCM+速 or OpenFOAM速 ) and the optimisation algorithm controlling the change of hull form. This results in a hull form that is perfectly adapted to fulfil the optimisation goal within the prescribed limitations. Hull Optimisations Hull optimisation improves the efficiency of the vessel by changing the hull form in order to reduce the generated waves and thereby the energy used for propulsion. Optimisation of the hull form can lead to significant improvements in resistance and hence large fuel savings. Bulb and aft ship hull form optimisation or new building projects are carried out over a range of operation conditions in order to cover the operational profile of the vessel. Baseline Optimised (Resistance decreased 15 %)
  • 7. 7 Retrofit Optimisation Increased fuel prices force some ships to transit at lower speeds than design speed (slow steaming), and considering a retrofit for the bulbous bow or aft ship might be beneficial. Having the experience and technical skills, OSK-ShipTech A/S is able to help our clients and assist the owner in deciding the optimal retrofit for each vessel and tailoring the right solution offering an attractive return of investment. Example of Retrofit: Bulb Optimisation The bulbous bow highly influences the resistance of the vessel. If the vessel is not operating at the speed and draft it was originally designed for, a new bulbous bow can prove to be a very good investment. For a bulbous bow to be successful, the shape has to be optimised to the operational profile in order to minimise fuel consumption over the range of conditions. Within bulb optimisation, OSK-ShipTech A/S offers: Reduction of hull resistance / savings on fuel consumption consistent with the operational profile Quick delivery of retrofit design including hydrodynamics and steel design
  • 8. 8 Propeller Simulation One of the big challenges in marine CFD is modelling the flow past propellers. OSK-ShipTech A/S has focused a great deal on this issue and is able to deliver trustworthy results tailored to each project. Optimisation of the propulsion unit has a direct impact on the overall efficiency of the vessel. Optimisation of the propellers provided by OSK-ShipTech A/S can lead to the following improvements: Increased overall efficiency of the vessel / reduced fuel consumption Reduction of cavitation Reduction of noise and vibrations
  • 9. 9 Manoeuvring Abilities A CFD analysis can be a powerful and cost-effective tool for prediction of the manoeuvring abilities of ships. In contrast to tank tests in model scale, OSK-ShipTech A/S calculates the manoeuvring abilities in full scale using high-end CFD calculations. These calculations make it possible to predict the compliance with e.g. IMO Resolution MSC.137(76) as early as design stage after which any needed suggestions for improvements will be provided by OSK-ShipTech A/S. With manoeuvring calculation from OSK-ShipTech A/S, the ship can confidently sail on its full scale sea trial. Examples of simulations: Turning circle Zig-Zag test Course keeping Wave elevation during Zig-Zag test Turning circle test
  • 10. 10 Environmental Forces Marine applications are exposed to powerful forces of nature and very often, conceptual and structural design is based on the exposure to these forces. Accurate estimation of the forces of nature may be the key to success of a given project. OSK-ShipTech A/S is able to provide CFD simulations of: Wave forces: Regular waves - Irregular wave spectrums - Freak waves Wind forces Current forces CFD simulation for Dynamic Positioning (DP) Wave loads on a cylinder
  • 11. 11 Additional Applications OSK-Shiptech A/S has extensive experience in the use of CFD in a wide range of other fluid applications such as: Pipe flows Pump simulations Heat exchangers Sloshing tanks Offshore structures Ventilation systems Fire simulations High-speed vessels Catamarans Exhaust simulations Sail simulation and optimisation Azimuth propellers Wave loads on a lattice tower Simulation of a centrifugal pump Wake behind catamaran