Dunamic Positioning Committee Marine Technology Society Thrusters Numerical Analysis of Flow Around a Thruster Norbert W.H.Bulten Wartsila Propulson,Netherlands October 17-18,2006 Return to Session Directory
Thrusters Numerical Analysis of Flow Around a Thruster Norbert W. H. Bulten Wärtsilä Propulson, Netherlands October 17-18, 2006 Return to Session Directory
Numerical Analysis of Flow around a Thruster Norbert Bulten 18 October 2006 ©Vartsila WARTSILA
© Wärtsilä Norbert Bulten 18 October 2006 Numerical Analysis of Flow around a Thruster
Topics General introduction about thrusters Application of nozzles Performance predictions issues ●Research method:CFD State-of-art numerical techniques Experience at Wartsila with CFD Basic priciples of CFD ●Results of analyses Propeller-HR-nozzle configuration Complete thruster-unit ●Conclusions ©Vartsila 2 WARTSILA
© Wärtsilä 2 General introduction about thrusters Application of nozzles Performance predictions issues Research method: CFD State-of-art numerical techniques Experience at Wartsila with CFD Basic priciples of CFD Results of analyses Propeller-HR-nozzle configuration Complete thruster-unit Conclusions Topics
General thruster introduction Thrusters are applied for: ■Dynamic positioning ■Heavy lift vessels ■ Offshore support vessels ■Cable laying vessels ■TugS O ©Wartsila 3 WARTSILA
© Wärtsilä 3 General thruster introduction Thrusters are applied for: Dynamic positioning Heavy lift vessels Offshore support vessels Cable laying vessels Tugs
General thruster introduction Thrusters can be equipped with or without nozzle Open propeller o ©Vartsila Lips HR-nozzle WARTSILA
© Wärtsilä 4 General thruster introduction Thrusters can be equipped with or without nozzle Lips HR-nozzle Open propeller
Application of nozzles Nozzles are applied to increase thrust at low ship speed. Typical examples of low speed operation are: ■Bollard pull ■Dynamic positioning ■Fishing ■Heavy lift vessels ©Wartsila 5 WARTSILA
© Wärtsilä 5 Application of nozzles Nozzles are applied to increase thrust at low ship speed. Typical examples of low speed operation are: Bollard pull Dynamic positioning Fishing Heavy lift vessels
Application of nozzles Basic principle of nozzle:section acts similar as wing section o Pressure distribution around nozzle changes due to propeller action Additional thrust ++++++++++ O ©Wartsila WARTSILA
© Wärtsilä 6 Application of nozzles Basic principle of nozzle: section acts similar as wing section Pressure distribution around nozzle changes due to propeller action Additional thrust
Typical nozzle types Cross-sectional profile of Profile 19A nozzle. nozzles: ■19A ■37 ■LIPS-HR Profile 37-nozzle. Full scale measurements show 8%bollard pull improvement for HR compared to 19A Profile HR -nozzle. ©Vartsila WARTSILA
© Wärtsilä 7 Typical nozzle types Cross-sectional profile of nozzles: 19A 37 LIPS-HR Full scale measurements show 8% bollard pull improvement for HR compared to 19A
Performance prediction of nozzles In general,open propeller performance is based on model scale experiments. o Full scale performance is based on measured data in combination with scaling methods(ITTC'78) Scaling of ducted propellers(=propeller nozzle configuration)not well understood New nozzle designs,like Lips HR-nozzle,do not behave like old 19A nozzles. Advanced numerical method(CFD)is applied to predict full scale performance of propeller with HR-nozzle ©Wartsila WARTSILA
© Wärtsilä 8 Performance prediction of nozzles In general, open propeller performance is based on model scale experiments. Full scale performance is based on measured data in combination with scaling methods (ITTC’78) Scaling of ducted propellers (=propeller + nozzle configuration) not well understood New nozzle designs, like Lips HR-nozzle, do not behave like old 19A nozzles. Advanced numerical method (CFD) is applied to predict full scale performance of propeller with HR-nozzle
Performance prediction of thrusters Conventional thruster performance is based on model scale measurements. ● Scaling of thruster performance is more complex than ducted propeller,due to strut and thruster house o Full scale performance of thruster unit can be based directly on state-of-the-art numerical calculations. ©Vartsila WARTSILA
© Wärtsilä 9 Performance prediction of thrusters Conventional thruster performance is based on model scale measurements. Scaling of thruster performance is more complex than ducted propeller, due to strut and thruster house Full scale performance of thruster unit can be based directly on state-of-the-art numerical calculations
