Photogrammetry Based Flying Shape Investigation of Downwind Sails in the Wind Tunnel and at Full Scale on a Sailing Yacht

2011 ◽  
Author(s):  
Johannes Mausolf ◽  
Julien Deparday ◽  
Kai Graf ◽  
Hannes Renzsch ◽  
Christoph Böhm
Keyword(s):  
Wind Tunnel ◽  
Driving Force ◽  
Full Scale ◽  
Shape Measurement ◽  
Stochastic Environment ◽  
Measurement Principle ◽  
Sailing Yacht

This paper describes model and full scale measurements of the flying shape of spinnakers that have been developed for a 38’ c/r yacht. The flying shape measurement principle was based on photogrammetry. Motivation behind this study was to investigate and compare the flying shape as obtained in the wind tunnel and at full scale. While flying shape measurements in the wind tunnel are straight forward to do providing quite accurate results, respective measurements at full scale in natural, stochastic environment turned out to be challenging. As a result of the comparison it can be shown that flying shape at full scale and model agrees well for given trim settings of the spinnaker, while trim settings for driving force optima where quite different.

Pressure Measurements on Yacht Sails: Development of a new system for wind tunnel and full scale testing

2016 ◽  
Author(s):  
Fabio Fossati ◽  
Ilmas Bayati ◽  
Sara Muggiasca ◽  
Ambra Vandone ◽  
Gabriele Campanardi ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Unsteady Aerodynamics ◽  
Research Field ◽  
Full Scale ◽  
Measuring System ◽  
Windward Side ◽  
Pressure System ◽  
Operational Conditions ◽  
Sailing Yacht ◽  
Full Scale Testing

The paper presents an overview of a joint project developed among Politecnico di Milano, CSEM and North Sails, aiming at developing a new sail pressure measurement system based on MEMS sensors (an excellent compromise between size, performance, costs and operational conditions) and pressure strips and pads technology. These devices were designed and produced to give differential measurement between the leeward and windward side of the sails. The project has been developed within the Lecco Innovation Hub Sailing Yacht Lab, a 10 m length sailing dynamometer which intend to be the reference contemporary full scale measurement device in the sailing yacht engineering research field, to enhance the insight of sail steady and unsteady aerodynamics [1]. The pressure system is described in details as well as the data acquisition process and system metrological validation is provided; furthermore, some results obtained during a wind tunnel campaign carried out at Politecnico di Milano Wind Tunnel, as a benchmark of the whole measuring system for future full scale application, are reported and discussed in details. Moreover, the system configuration for full scale testing, which is still under development, is also described.

Wind Tunnel to Full Scale Mapping of Winds and Loads for Launch-Vehicle Ground Wind Loads

2021 ◽  
Author(s):  
Thomas G. Ivanco ◽  
Donald F. Keller ◽  
Jennifer L. Pinkerton
Keyword(s):  
Wind Tunnel ◽  
Launch Vehicle ◽  
Full Scale ◽  
Wind Loads

Characterization of wind-induced pressure on membrane roofs based on full-scale wind tunnel testing

2021 ◽  
Vol 235 ◽  
pp. 112101
Author(s):  
Johnny Estephan ◽  
Changda Feng ◽  
Arindam Gan Chowdhury ◽  
Mauricio Chavez ◽  
Appupillai Baskaran ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Full Scale ◽  
Wind Tunnel Testing ◽  
Tunnel Testing

Sailing Yacht Rig Improvements Through Viscous Computational Fluid Dynamics

2005 ◽  
Author(s):  
Vincent G. Chapin ◽  
Romaric Neyhousser ◽  
Stephane Jamme ◽  
Guillaume Dulliand ◽  
Patrick Chassaing
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
High Speed ◽  
Stokes Equations ◽  
Wind Tunnel Test ◽  
Physical Modelling ◽  
Optimized Design ◽  
Linear Interaction ◽  
Sailing Yacht

In this paper we propose a rational viscous Computational Fluid Dynamics (CFD) methodology applied to sailing yacht rig aerodynamic design and analysis. After an outlook of present challenges in high speed sailing, we emphasized the necessity of innovation and CFD to conceive, validate and optimize new aero-hydrodynamic concepts. Then, we present our CFD methodology through CAD, mesh generation, numerical and physical modelling choices, and their validation on typical rig configurations through wind-tunnel test comparisons. The methodology defined, we illustrate the relevance and wide potential of advanced numerical tools to investigate sailing yacht rig design questions like the relation between sail camber, propulsive force and aerodynamic finesse, and like the mast-mainsail non linear interaction. Through these examples, it is shown how sailing yacht rig improvements may be drawn by using viscous CFD based on Reynolds Averaged Navier-Stokes equations (RANS). Then the extensive use of viscous CFD, rather than wind-tunnel tests on scale models, for the evaluation or ranking of improved designs with increased time savings. Viscous CFD methodology is used on a preliminary study of the complex and largely unknown Yves Parlier Hydraplaneur double rig. We show how it is possible to increase our understanding of his flow physics with strong sail interactions, and we hope this methodology will open new roads toward optimized design. Throughout the paper, the necessary comparison between CFD and wind-tunnel test will be presented to focus on limitations and drawbacks of viscous CFD tools, and to address future improvements.

A New Method of Modeling Underexpanded Exhaust Plumes for Wind Tunnel Aerodynamic Testing

1989 ◽  
Vol 111 (4) ◽  
pp. 748-754
Author(s):  
V. Salemann ◽  
J. M. Williams
Keyword(s):  
Wind Tunnel ◽  
Free Stream ◽  
Dynamic Pressure ◽  
Pressure Ratio ◽  
Area Ratio ◽  
Full Scale ◽  
New Method ◽  
Thrust Coefficient ◽  
Model Scale ◽  
Exhaust Plumes

A new method for modeling hot underexpanded exhaust plumes with cold model scale plumes in aerodynamic wind tunnel testing has been developed. The method is applicable to aeropropulsion testing where significant interaction between the exhaust and the free stream and aftbody may be present. The technique scales the model and nozzle external geometry, including the nozzle exit area, matches the model jet to free-stream dynamic pressure ratio to full-scale jet to free-stream dynamic pressure ratio, and matches the model thrust coefficient to full-scale thrust coefficient. The technique does not require scaling of the internal nozzle geometry. A generalized method of characteristic computer code was used to predict the plume shapes of a hot (γ = 1.2) half-scale nozzle of area ratio 3.2 and of a cold (γ = 1.4) model scale nozzle of area ratio 1.3, whose pressure ratio and area ratio were selected to satisfy the above criteria and other testing requirements. The plume shapes showed good agreement. Code validity was checked by comparing code results for cold air exhausting into a quiescent atmosphere to pilot surveys and shadowgraphs of model nozzle plumes taken in a static facility.

Full-Scale Wind-Tunnel Investigation of an Ayres S2R-800 Thrush Agricultural Airplane

1979 ◽  
Author(s):  
Joseph L. Johnson ◽  
H. Clyde Mclemore ◽  
Richard White ◽  
Frank L. Jordan
Keyword(s):  
Wind Tunnel ◽  
Full Scale
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