Races using kitefoil and windfoil surfboards have been in the Olympic Games for the first time in Paris 2024,signalling their relevance in sailing sports.However,the dynamics of these devices is yet not well understoo...Races using kitefoil and windfoil surfboards have been in the Olympic Games for the first time in Paris 2024,signalling their relevance in sailing sports.However,the dynamics of these devices is yet not well understood,in particular the influence on the hydrodynamic forces and moments of the distance of the foil to the free surface.Considering this,the present paper documents an experimental investigation in which forces and torque produced,under uniform flow,by a full-scale state-of-the-art hydrofoil(suitable both for kitesurf and windsurf)were measured.A range of velocities,angles of attack,and submergences were tested,leading to Froude numbers based on submergence with maximum values around five,a typical range in actual sailing conditions.From these tests,formulae for the hydrodynamic coefficients have been proposed.They can be used for developing Velocity Prediction Programs(VPP)for this kind of craft,a necessary tool to plan racing configurations and to analyze their racing performance.With the aim of making the experimental data useful for benchmarking numerical models and for future research on related topics such as foil ventilation and transition to turbulence,the specimen’s 3D file is provided as supplementary material to this paper.展开更多
The establishment and realization of the VPP calucation's model for the functional analytic theory are discussed in this paper.Functional analyzing method is a theoretical model of the VPP calculation which can el...The establishment and realization of the VPP calucation's model for the functional analytic theory are discussed in this paper.Functional analyzing method is a theoretical model of the VPP calculation which can eliminate the influence of the sail and board's size skillfully,so it can be regarded as a brief standard of the sailboard's VPP results.As a brief watery dynamical model,resistance on board can be regarded as a direct proportion to the square of the boat-velocity.The boat-velocities at the state of six wind-velocities(3m/s-8m/s) with angles of 25°-180° are obtained by calculating,which provides an important gist of the sailing-route's selection in upwind-sailing.展开更多
文摘Races using kitefoil and windfoil surfboards have been in the Olympic Games for the first time in Paris 2024,signalling their relevance in sailing sports.However,the dynamics of these devices is yet not well understood,in particular the influence on the hydrodynamic forces and moments of the distance of the foil to the free surface.Considering this,the present paper documents an experimental investigation in which forces and torque produced,under uniform flow,by a full-scale state-of-the-art hydrofoil(suitable both for kitesurf and windsurf)were measured.A range of velocities,angles of attack,and submergences were tested,leading to Froude numbers based on submergence with maximum values around five,a typical range in actual sailing conditions.From these tests,formulae for the hydrodynamic coefficients have been proposed.They can be used for developing Velocity Prediction Programs(VPP)for this kind of craft,a necessary tool to plan racing configurations and to analyze their racing performance.With the aim of making the experimental data useful for benchmarking numerical models and for future research on related topics such as foil ventilation and transition to turbulence,the specimen’s 3D file is provided as supplementary material to this paper.
基金This work was supported by the key sur mounting event of General Administration of Sport of China for 2004 Olympics:Research of the optimal incline-angle and route in sailboard sports(03056).
文摘The establishment and realization of the VPP calucation's model for the functional analytic theory are discussed in this paper.Functional analyzing method is a theoretical model of the VPP calculation which can eliminate the influence of the sail and board's size skillfully,so it can be regarded as a brief standard of the sailboard's VPP results.As a brief watery dynamical model,resistance on board can be regarded as a direct proportion to the square of the boat-velocity.The boat-velocities at the state of six wind-velocities(3m/s-8m/s) with angles of 25°-180° are obtained by calculating,which provides an important gist of the sailing-route's selection in upwind-sailing.
