Editing Parasitic drag (section)

{{Short description|Aerodynamic resistance against the motion of an object}}
[[Image:Drag curves for aircraft in flight.svg|thumb|x250px|right|[[Drag curve]] for a lifting body in steady flight]]
'''Parasitic drag''', also known as '''profile drag''',<ref name="Anderson">{{cite book |last1=Anderson |first1=John D. Jr. |title=Fundamentals of aerodynamics |date=1991 |publisher=McGraw-Hill |location=New York |isbn=0-07-001679-8 |edition=2nd}}</ref>{{rp|254}}<ref name="Anderson Introduction">{{cite book |last1=Anderson |first1=John D. Jr. |title=Introduction to flight |date=2016 |publisher=McGraw Hill Education |location=New York, NY |isbn=978-0-07-802767-3 |page=242 |edition=Eighth}}</ref>{{rp|256}} is a type of [[Drag (physics)#Aerodynamics|aerodynamic drag]] that acts on any object when the object is moving through a fluid. Parasitic drag is defined as the combination of ''[[#Form drag|form drag]]'' and ''[[skin friction drag]]''.<ref>Clancy, L.J. (1975). ''Aerodynamics'', Sub-section 5.9. Pitman Publishing. {{ISBN|0 273 01120 0}}</ref><ref name="Anderson"/>{{rp|641-642}}<ref name="Gowree">{{cite thesis |last1=Gowree |first1=Erwin Ricky |title=Influence of Attachment Line Flow on Form Drag |date=20 May 2014 |url=https://openaccess.city.ac.uk/id/eprint/12239/ |access-date=22 March 2022|type=doctoral }}</ref>{{rp|19}}

It is named as such because it is not useful, in contrast with [[lift-induced drag]] which is created when an [[airfoil]] generates lift. All objects experience parasitic drag, regardless of whether they generate [[lift (force)|lift]]. Parasitic drag comprises all types of drag except lift-induced drag, and the total drag on an aircraft or other object which generates lift is the sum of parasitic drag and [[lift-induced drag]].<ref name="PHAK">{{cite book |url=https://www.faa.gov/sites/faa.gov/files/07_phak_ch5_0.pdf |title=Pilot's Handbook of Aeronautical Knowledge |publisher=FAA |page=Chapter 5, Aerodynamics of flight |quote=The first is called parasite because it in no way functions to aid flight, while the second, induced drag, is a result of an airfoil developing lift.}}</ref>