Editing Sailing (section)

====Drag predominance (parachute mode)====
When sailing craft are on a course where the angle between the sail and the apparent wind (the angle of attack) exceeds the point of maximum lift, separation of flow occurs.<ref>{{Citation
 | last1 = Collie
 | first1 = S. J.
 | last2 = Jackson
 | first2 = P. S.
 | last3 = Jackson
 | first3 = M.
 | last4 = Gerritsen
 | first5 = J.B.
 | last5 = Fallow
 | title = Two-dimensional CFD-based parametric analysis of down-wind sail designs
 | journal = The University of Auckland
 | date = 2006
 | url = http://syr.stanford.edu/RINA_Steve.pdf
 | access-date = 4 April 2015
 | archive-date = 28 July 2010
 | archive-url = https://web.archive.org/web/20100728123723/http://syr.stanford.edu/RINA_Steve.pdf
 | url-status = dead
 }}</ref> Drag increases and lift decreases with increasing angle of attack as the separation becomes progressively pronounced until the sail is perpendicular to the apparent wind, when lift becomes negligible and drag predominates. In addition to the sails used upwind, [[spinnaker]]s provide area and curvature appropriate for sailing with separated flow on downwind points of sail, analogous to parachutes, which provide both lift and drag.<ref name=Textor>
{{cite book
 | last = Textor
 | first = Ken
 | title = The New Book of Sail Trim
 | publisher = Sheridan House, Inc.
 | date = 1995
 | url = https://books.google.com/books?id=2JIbS0c1XPwC&pg=PA50
 | page = 50
 | isbn = 978-0-924486-81-4 }}
</ref>
{{center|
;Downwind sailing with a spinnaker
}}
<gallery mode="packed" heights="175px">
File:Sailboat on broad reach with spinnaker.jpg|Spinnaker set for a broad reach, generating both lift, with separated flow, and drag.
File:Spinnaker trimmed for broad reach.jpg|Spinnaker cross-section trimmed for a broad reach showing transition from boundary layer to separated flow where vortex shedding commences.
File:Amante Choate 48 photo D Ramey Logan.jpg|Symmetric spinnaker while running downwind, primarily generating drag.
File:Symmetrical spinnaker with following apparent wind.jpg|Symmetric spinnaker cross-section with following apparent wind, showing vortex shedding.
</gallery>