The hydrodynamic performance of high-speed planing hulls has gained considerable interest,with recent advancements in computational fluid dynamics and hull design techniques enhancing the understanding of planing hull...The hydrodynamic performance of high-speed planing hulls has gained considerable interest,with recent advancements in computational fluid dynamics and hull design techniques enhancing the understanding of planing hull hydrodynamics.In this study,we conducted a numerical investigation using the Reynolds-averaged Navier-Stokes approach with overset grids to capture large motions at high speeds.This study aims to improve the hydrodynamic performances of planing hulls,specifically focusing on total resistance,trim,and sinkage.The initial Fridsma hull with a deadrise angle of 20°has been used for validation,demonstrating good agreement with measurements at different Froude numbers.Subsequently,new configurations based on the Fridsma hull have been designed by varying the deadrise angle,number of chines,and transverse steps.Our findings reveal a correlation between the deadrise angle,the number of chines,and the Froude number.As the deadrise angle increases,total resistance also increases.Additionally,a single chine yields superior results at higher Froude numbers,while multiple chines offer advantages at lower values.The introduction of transverse steps consistently increases total resistance,highlighting their role in improving planing hull performance.This research not only offers valuable insights into planing hull design but also leverages state-of-the-art numerical methods to advance the understanding of hydrodynamic behaviors at high ship speeds.展开更多
Ship propulsion performance heavily depends on cavitation,increasing the recent interest in this field to lower ship emissions.Academic research on the effects of cavitation is generally based on the open-water propel...Ship propulsion performance heavily depends on cavitation,increasing the recent interest in this field to lower ship emissions.Academic research on the effects of cavitation is generally based on the open-water propeller performance but the interactions of the cavitating propeller with the ship hull significantly affect the propulsion performance of the ship.In this study,we first investigate the INSEAN E779A propeller by a RANSE-based CFD in open-water conditions.The numerical implementation and the selected grid after sensitivity analysis partially succeeded in modeling the cavitating flow around the propeller.Satisfactory agreement was observed compared to experimental measurements.Then,using the open-water data as input,the propeller’s performance behind a full-scale ship was calculated under self-propulsion conditions.Despite being an undesired incident,we found a rare condition in which cavitation enhances propulsion efficiency.Atσ=1.5;the propeller rotation rate was lower,while the thrust and torque coefficients were higher.展开更多
基金Supported by the UK Department for Transport,as part of the UK Shipping Office for Reducing Emissions(UK SHORE)Programme and the UK Engineering and Physical Sciences Research Council(EPSRC)[grant number EP/Y024605/1].
文摘The hydrodynamic performance of high-speed planing hulls has gained considerable interest,with recent advancements in computational fluid dynamics and hull design techniques enhancing the understanding of planing hull hydrodynamics.In this study,we conducted a numerical investigation using the Reynolds-averaged Navier-Stokes approach with overset grids to capture large motions at high speeds.This study aims to improve the hydrodynamic performances of planing hulls,specifically focusing on total resistance,trim,and sinkage.The initial Fridsma hull with a deadrise angle of 20°has been used for validation,demonstrating good agreement with measurements at different Froude numbers.Subsequently,new configurations based on the Fridsma hull have been designed by varying the deadrise angle,number of chines,and transverse steps.Our findings reveal a correlation between the deadrise angle,the number of chines,and the Froude number.As the deadrise angle increases,total resistance also increases.Additionally,a single chine yields superior results at higher Froude numbers,while multiple chines offer advantages at lower values.The introduction of transverse steps consistently increases total resistance,highlighting their role in improving planing hull performance.This research not only offers valuable insights into planing hull design but also leverages state-of-the-art numerical methods to advance the understanding of hydrodynamic behaviors at high ship speeds.
文摘Ship propulsion performance heavily depends on cavitation,increasing the recent interest in this field to lower ship emissions.Academic research on the effects of cavitation is generally based on the open-water propeller performance but the interactions of the cavitating propeller with the ship hull significantly affect the propulsion performance of the ship.In this study,we first investigate the INSEAN E779A propeller by a RANSE-based CFD in open-water conditions.The numerical implementation and the selected grid after sensitivity analysis partially succeeded in modeling the cavitating flow around the propeller.Satisfactory agreement was observed compared to experimental measurements.Then,using the open-water data as input,the propeller’s performance behind a full-scale ship was calculated under self-propulsion conditions.Despite being an undesired incident,we found a rare condition in which cavitation enhances propulsion efficiency.Atσ=1.5;the propeller rotation rate was lower,while the thrust and torque coefficients were higher.
