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grille block is often used. A grille block covers up a portion of, or the entirety of, the front grille of a vehicle. In most high efficiency models or in vehicles with low drag coefficients, a very small grille will already be built into the vehicle's design, eliminating the need for a grille block. The grille in most production vehicles is generally designed to maximize air flow through the radiator where it exits into the engine compartment. This design can actually create too much airflow into the engine compartment, preventing it from warming up in a timely manner, and in such cases a grille block is used to increase engine performance and reduce vehicle drag simultaneously.
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automotive drag for the higher performance vehicles. By the late 1960s scientists also became aware of the significant increase in sound levels emitted by automobiles at high speed. These effects were understood to increase the intensity of sound levels for adjacent land uses at a non-linear rate. Soon highway engineers began to design roadways to consider the speed effects of aerodynamic drag produced sound levels, and automobile manufacturers considered the same factors in vehicle design.
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90:
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144:, and in this case the cameras are claimed by Honda to have decreased aerodynamic drag by "around 90% compared to conventional door mirrors" which contributed to an approximately 3.8% reduction in drag for the entire vehicle. It is estimated that two side mirrors are responsible for 2 to 7% of the total aerodynamic drag of a motor vehicle, and that removing them could improve fuel economy by 1.5–2 miles per US gallon.
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the rear deck lid will increase downforce, reducing lift at high speeds while incurring a drag penalty. Flat spoilers, possibly angled slightly downward may reduce turbulence and thereby reduce the coefficient of drag. Some cars now feature automatically adjustable rear spoilers, so at lower speed the effect on drag is reduced when the benefits of reduced lift are not required.
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are often made as extensions of the body panels of the vehicles and cover the entire wheel wells. Much like smooth wheel covers this modification reduces the drag of the vehicle by preventing any air from becoming trapped in the wheel well and assists in streamlining the body of the vehicle. Fender
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in a vehicle's design is to counteract lift, thereby increasing stability at higher speeds. In order to achieve the lowest possible drag, air must flow around the streamlined body of the vehicle without coming into contact with any areas of possible turbulence. A rear spoiler design that stands off
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part, meaning any part of the vehicle that was originally manufactured on the vehicle. Most production sports cars and high efficiency vehicles come standard with many of these deletions in order to be competitive in the automotive and race market, while others choose to keep these drag-increasing
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is a truncated boattail. It is created as an extension of the rear of the vehicle, moving the rear backward at a slight angle toward the bumper of the car. This can reduce drag as well but a boattail would reduce the vehicle's drag more. Nonetheless, for practical and style reasons, a kammback is
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of a vehicle is used to direct air through the radiator. In a streamlined design the air flows around the vehicle rather than through; however, the grille of a vehicle redirects airflow from around the vehicle to through the vehicle, which then increases the drag. In order to reduce this impact a
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are often applied. Smooth wheel covers are hub caps with no holes in them for air to pass through. This design reduces drag; however, it may cause the brakes to heat up more quickly because the covers prevent airflow around the brake system. As a result, this modification is more commonly seen in
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The frictional force of aerodynamic drag increases significantly with vehicle speed. As early as the 1920s engineers began to consider automobile shape in reducing aerodynamic drag at higher speeds. By the 1950s German and
British automotive engineers were systematically analyzing the effects of
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both increase the frontal area of the vehicle and increase the coefficient of drag since they protrude from the side of the vehicle. In order to decrease the impact that side mirrors have on the drag of the vehicle the side mirrors can be replaced with smaller mirrors or mirrors with a different
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The underside of a vehicle often traps air in various places and adds turbulence around the vehicle. In most racing vehicles this is eliminated by covering the entire underside of the vehicle in what is called an under tray. This tray prevents any air from becoming trapped under the vehicle and
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that allows it to travel faster through a corner by holding the car to the track or road surface. Some elements to increase vehicle downforce will also increase drag. It is very important to produce a good downward aerodynamic force because it affects the car's speed and traction.
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commonly found protruding from the front of the vehicle can be relocated and changed in design to rid the car of this added drag. The most common replacement for the standard car antenna is the shark fin antenna found in most high efficiency vehicles.
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of the 2010s are replacing mirrors with tiny cameras but this option is not common for production cars because most countries require side mirrors. One of the first production passenger automobiles to swap out mirrors for cameras was the
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testing. For the most accurate results from a wind tunnel test, the tunnel is sometimes equipped with a rolling road. This is a movable floor for the working section, which moves at the same speed as the air flow. This prevents a
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Passenger and commercial ground vehicles have very specific design constraints such as their intended purpose, high safety standards (requiring, for example, more 'dead' structural space to act as crumple zones), and certain
244:. Front fender skirts have the same effect on reducing drag as the rear wheel skirts, but must be further offset from the body in order to compensate for the tire sticking out from the body of the vehicle as turns are made.
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When air flows around the wheel wells it gets disturbed by the rims of the vehicles and forms an area of turbulence around the wheel. In order for the air to flow more smoothly around the wheel well, smooth
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468:, Proceedings of the ASCE, Urban Transportation Division specialty conference, May 21/23, 1973, Chicago, Illinois. by American Society of Civil Engineers. Urban Transportation Division
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A boattail can greatly reduce a vehicle's total drag. Boattails create a teardrop shape that will give the vehicle a more streamlined profile, reducing the occurrence of drag inducing
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skirts are more commonly found on the rear wheel wells of a vehicle because the tires do not turn and the design is much simpler. This is commonly seen in vehicles such as the
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A rear spoiler usually comes standard in most sports vehicles and resembles the shape of a raised wing in the rear of the vehicle. The main purpose of a
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Proceedings: Institution of
Mechanical Engineers (Great Britain). Automobile Division: Institution of Mechanical Engineers, Great Britain (1957)
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at high speeds. Air is also considered a fluid in this case. For some classes of racing vehicles, it may also be important to produce
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Air curtains divert air flow from slots in the body and guide it towards the outside edges of the wheel wells.
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part, or part that has been installed on the vehicle after production, or having to modify and remove an
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and frontal drag of the vehicle with little cost and effort. Deletion can be as simple as removing an
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aspects of the vehicle for their visual aspects, or to fit the typical uses of their customer base.
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The deletion of parts on a vehicle is an easy way for designers and vehicle owners to reduce
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The characteristic shape of a road vehicle is much less streamlined compared to an aircraft.
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While they do not have the biggest impact on the drag coefficient due to their small size,
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820:"Background Research." Automobile Aerodynamics. 18 May 2008. DHS. 18 May 2009 <
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712:"How Air Curtains on F-150 Help Reduce Aerodynamic Drag and Aid Fuel Efficiency"
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was the first series-produced aerodynamically designed automobile, before the
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from forming on the floor of the working section and affecting the results.
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Automotive aerodynamics differs from aircraft aerodynamics in several ways:
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One of the first cars to generate downforce - The
Prevost analysed in CFD
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than an aircraft, and its motion is less affected by aerodynamic forces.
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Designing tomorrow's cars: from concept, step-by-step, to detail design
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The
Aerodynamics of Heavy Vehicles: Trucks, Buses, and Trains, Volume 1
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Computational Fluid
Dynamics for Engineers: From Panel to Navier-Stokes
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The vehicle operates very close to the ground, rather than in free air.
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more commonly seen in racing, high efficiency vehicles, and trucking.
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high efficiency vehicles rather than sports cars or racing vehicles.
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639:"Estimation of The Drag of a Roof Mounted Antenna (AU Ford Falcon)"
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73:
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480:"Aerodynamic Tips and Tricks You Can Use for Better Performance"
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Tuncer Cebeci, Jian P. Shao, Fassi
Kafyeke, Eric Laurendeau,
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A truck with added bodywork on top of the cab to reduce drag.
613:"A mirrorless future? NHTSA seeks input on exterior cameras"
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The relationship between highway planning and urban noise
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Downforce describes the downward pressure created by the
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733:"Designing for design's sake—with aerodynamics built in"
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http://web-aerodynamics.webs.com/backgroundresearch.htm
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587:"Honda E To Get Side Camera Mirror System As Standard"
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One of the side effects of automotive aerodynamics is
561:"First drive review: Porsche Panamera Sport Turismo"
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519:"Reflections on side mirrors: testing drag vs. MPG"
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52:to improve traction and thus cornering abilities.
801:"Turbulent Boundary Layer Separation and Control"
194:2017 Land Rover Discovery with front air curtains
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279:The operating speeds are lower (and aerodynamic
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32:of road vehicles. Its main goals are reducing
803:. Stockholm: KTH Royal Institute of Technology
325:Automotive aerodynamics is studied using both
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670:"Drag Reduction on a Production Vehicle"
462:C. Michael Hogan & Gary L. Latshaw,
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735:(Press release). Honda. Archived from
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265:Comparison with aircraft aerodynamics
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502:Physics for Scientists and Engineers
16:Study of road vehicles aerodynamics
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14:
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688:"The 1M's Air Curtain in Detail"
303:Methods of studying aerodynamics
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686:Bridger, Gabriel (2010-12-13).
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478:Davis, Marlan (February 2009).
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242:first generation Honda Insight
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169:Alloy wheels with covers on a
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757:Korff, Walter Henry (1980).
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93:Streaklines over a model car
85:Strategies for reducing drag
7:
714:(Press release). 2015-07-15
645:. Australia. September 2005
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290:A ground vehicle has fewer
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44:forces and other causes of
40:, and preventing undesired
36:and wind noise, minimizing
21:Automobile drag coefficient
10:
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828:September 2, 2011, at the
783:Popular Mechanics Sep 1981
675:. UK: Coventry University.
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126:
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248:Boattails and Kammbacks
46:aerodynamic instability
26:Automotive aerodynamics
861:Automotive engineering
799:Lögdberg, Ola (2008).
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173:
94:
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64:Edmund Rumpler's 1921
402:Ground effect in cars
382:Drag reduction system
372:Aerodynamic stability
356:characteristics of a
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202:Partial grille blocks
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761:. M-C Publications.
486:. US. Archived from
28:is the study of the
619:. SAE International
437:, Springer, 2005,
327:computer modelling
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292:degrees of freedom
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611:Brooke, Lindsay.
585:Fossdyke, James.
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346:Main article:
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319:seed dispersal
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866:Aerodynamics
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805:. Retrieved
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788:Google Books
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741:. Retrieved
737:the original
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716:. Retrieved
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567:. 2012-12-07
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549:Google Books
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527:. Retrieved
525:. 2006-08-31
523:MetroMPG.com
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507:Google Books
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488:the original
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298:regulations.
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179:wheel covers
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137:concept cars
132:Side mirrors
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120:rear spoiler
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66:Tropfenwagen
30:aerodynamics
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354:aerodynamic
331:wind tunnel
215:Under trays
103:aftermarket
855:Categories
807:2019-03-03
743:2018-02-20
718:2018-02-10
697:2018-02-10
692:BimmerFile
649:2019-03-03
643:Virtual V8
571:2013-03-01
529:2018-12-07
419:References
407:Slipstream
287:of speed).
206:The front
19:See also:
387:Downforce
348:Downforce
342:Downforce
99:parasitic
50:downforce
826:Archived
617:SAE News
377:Drafting
365:See also
258:kammback
114:Spoilers
74:Tatra 77
72:and the
565:Autocar
142:Honda e
127:Mirrors
56:History
765:
591:Motor1
441:
285:square
208:grille
161:Wheels
824:>
673:(PDF)
623:7 May
596:7 May
763:ISBN
625:2021
598:2021
439:ISBN
412:Wing
329:and
281:drag
256:. A
42:lift
34:drag
358:car
107:OEM
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