Experimental analysis of a strong fluid–structure interaction on a soft membrane—Application to the flapping of a yacht downwind sail

Deparday, Julien; Augier, Benoît; Bot, Patrick

doi:10.1016/j.jfluidstructs.2018.06.003

Cited by 11 publications

(10 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The investigation is repeated for four spinnaker models with different structural properties (see 2.2) but identical design shape. These time-resolved measurements for a large range of trim settings, for different values of wind speed and angle contribute to build a rich database to characterize the dynamic spinnaker behavior, which can be compared to full-scale results (Deparday et al (2018)) and remains essential for unsteady numerical/ experimental comparisons. The experimental set-up and the sails used for this study are firstly described.…”

Section: Closely Related Previous Workmentioning

confidence: 99%

“…This study is to be connected to a full-scale study by Deparday et al (2016bDeparday et al ( , 2017 where the dynamic effects of spinnaker flapping on forces and pressures are shown. A refined analysis of pressure variations associated to the luff flapping is given in Deparday et al (2018). From the present wind tunnel study, extrapolation to full scale is not straightforward as there is no similitude particularly in terms of structural properties.…”

mentioning

confidence: 91%

“…A common question among the sailing community for best performance is rather to trim the sail at sustained flapping or just before it appears. Downwind sails flapping-also known as curling-has only been recently scientifically studied thanks to full-scale experiments (Motta et al, 2014;Motta, 2015;Deparday, 2016;Deparday et al, 2018). It has been shown that this phenomenon results from a complex three-dimensional Fluid-Structure Interaction.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Performance enhancement of downwind sails due to leading edge flapping: A wind tunnel investigation

et al. 2018

View full text Add to dashboard Cite

This work presents a wind tunnel experimental study on the effect of the leading edge flapping on the aerodynamic performance of a spinnaker. Four J80-class spinnaker models, combining two different assembling structures (panel layout) and two different sail materials are tested at various wind speeds and wind angles in a wind tunnel. Results show that, for the wind angle range the spinnaker is designed for, the sustained periodic flapping of the sail leading edge has a significant benefit on performance, with 10% increase in drive force. In these model-scale tests, the sail structural properties did not show significant differences in performance, but affect the point where flapping sets in: a model with a stiffer material and a cross-cut panel layout starts flapping for a longer sheet length, compared to a lighter cloth and a tri-radial layout. Finally, it is shown that the nondimensional flapping frequency is rather constant 0.4 in the design range of wind angle, but it varies with the wind speed and sail structural properties on a smaller wind angle where the spinnaker is more stretched.

show abstract

Section: Closely Related Previous Workmentioning

confidence: 99%

mentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Performance enhancement of downwind sails due to leading edge flapping: A wind tunnel investigation

et al. 2018

View full text Add to dashboard Cite

show abstract

“…For this purpose, nowadays, several authors focus on the issue of predicting the flying shape a sail develops under the impact of flow forces. In this context, it is well known that the fluid-structure interaction (FSI) is a key feature to study these kinds of problems [11,16,22,23]. Today, sail designers use specific software to define the constructed (molded) sail shape based on their experience, but they do not have any certainty about the real flying shape [6].…”

Section: Introductionmentioning

confidence: 99%

Improving the Downwind Sail Design Process by Means of a Novel FSI Approach

Cirello

Ingrassia

Mancuso

et al. 2021

JMSE

View full text Add to dashboard Cite

The process of designing a sail can be a challenging task because of the difficulties in predicting the real aerodynamic performance. This is especially true in the case of downwind sails, where the evaluation of the real shapes and aerodynamic forces can be very complex because of turbulent and detached flows and the high-deformable behavior of structures. Of course, numerical methods are very useful and reliable tools to investigate sail performances, and their use, also as a result of the exponential growth of computational resources at a very low cost, is spreading more and more, even in not highly competitive fields. This paper presents a new methodology to support sail designers in evaluating and optimizing downwind sail performance and manufacturing. A new weakly coupled fluid–structure interaction (FSI) procedure has been developed to study downwind sails. The proposed method is parametric and automated and allows for investigating multiple kinds of sails under different sailing conditions. The study of a gennaker of a small sailing yacht is presented as a case study. Based on the numerical results obtained, an analytical formulation for calculating the sail corner loads has been also proposed. The novel proposed methodology could represent a promising approach to allow for the widespread and effective use of numerical methods in the design and manufacturing of yacht sails.

show abstract

“…The "verge of curling" recommendation is one of the most common pieces of advice that sailors follow for efficient sailing downwind with a spinnaker. Full-scale tests, thanks to the VOILENav project and the Sailing Fluids program, have recently investigated this complex unsteady Fluid-Structure Interaction phenomenon based on pressures and flying shape measurements (Motta et al 2014, Deparday, 2016, Deparday et al, 2018. These results showed that the curling of the leading edge of the spinnaker was associated with a pressure field evolution , whose propagation generates high suction peaks on the luff area.…”

Section: Introductionmentioning

confidence: 99%

Numerical and Experimental Comparison of Spinnaker Aerodynamics Close to Curling

Augier

Paillard²,

Sacher

et al. 2021

Journal of Sailing Technology

View full text Add to dashboard Cite

When sailing downwind with a spinnaker, the “verge of curling” is one of the common recommendations that sailors follow for efficient sailing. Wind tunnel experiments on spinnaker models conducted by Aubin et al. (2017) in the Twisted Flow Wind Tunnel of the Yacht Research Unit of the University of Auckland have shown that curling can be related to better performance at Apparent Wind Angle ≥ 100°. In the present article, we will focus on the aerodynamic performance jump observed at Apparent Wind Angle AWA = 100°, where the drive force increases up to 15% when the sail starts to flap. Thanks to four triggered HD cameras and coded targets stuck on the sail, three flying shapes of the spinnaker are reconstructed by photogrammetry for different sheet lengths from over trimmed to flapping occurrence. The pimpleFOAM solver from OpenFOAM is used to simulate the aerodynamics of the three rigid extracted flying shapes. Results highlight the ability of the model to simulate the experimental jump observed closed to curling and the significant confinement effect of the roof of the wind tunnel.

show abstract

Experimental analysis of a strong fluid–structure interaction on a soft membrane—Application to the flapping of a yacht downwind sail

Abstract: Experimental analysis of a strong fluid-structure interaction on a soft membrane -Application to the flapping of a yacht downwind sail. Journal of Fluids and Structures, Elsevier, 2018, 81, pp.

Cited by 11 publications

References 64 publications

Performance enhancement of downwind sails due to leading edge flapping: A wind tunnel investigation

Performance enhancement of downwind sails due to leading edge flapping: A wind tunnel investigation

Improving the Downwind Sail Design Process by Means of a Novel FSI Approach

Numerical and Experimental Comparison of Spinnaker Aerodynamics Close to Curling

Contact Info

Product

Resources

About