Aerodynamic study of Bentley Continental GT with Project O9

aerodynamic bodykit installed with Autodesk Flow Design

Changing drag coefficient from 0.31 to 0.26Aerodynamics is the study of how gases interact with moving bodies. Because the gas that we encounter most is air, aerodynamics is primarily concerned with the forces of drag and lift, which are caused by air passing over and around solid bodies. Engineers apply the principles of aerodynamics to the designs of many different things, including buildings, bridges and even soccer balls; however, of primary concern is the aerodynamics of aircraft and automobiles. Aerodynamics comes into play in the study of flight and the science of building and operating an aircraft, which is called aeronautics.Aeronautical engineers use the fundamentals of aerodynamics to design aircraft that fly through the Earth's atmosphere.

Aerodynamic dragThe most significant aerodynamic force that applies to nearly everything that moves through the air is drag. Drag is the force that opposes an aircraft's motion through the air, according to NASA. Drag is generated in the direction the air is moving when it encounters a solid object. In most cases, such as in automobiles and aircraft, drag is undesirable because it takes power to overcome it. There are, however, some cases when drag is beneficial, such as with parachutes, for example. To describe the amount of drag on an object, we use a value called the drag coefficient (cd). This number depends not only on the shape of the object but also on other factors, such as its speed and surface roughness, the density of the air and whether the flow is laminar (smooth) or turbulent. Forces that affect drag include the air pressure against the face of the object, the friction along the sides of the object and the relatively negative pressure, or suction, on the back of the object. For example, cd for a flat plate moving face-on through the air is about 1.3, a face-on cube is about 1, a sphere is about 0.5 and a teardrop shape is about 0.05. The drag coefficient for modern automobiles is 0.25 to 0.35, and for aircraft it is 0.01 to 0.03. Calculating cd can be complicated. For this reason, it is usually determined by computer simulations or wind tunnel experiments.

Aerodynamics of automobilesAutomobiles started using aerodynamic body shapes in the early part of their history. As engines became more powerful and cars became faster, automobile engineers realized that wind resistance significantly hindered their speed. The first cars to adopt improved aerodynamics, or streamlining, were racing cars and those attempting to break the land speed record. "Dreamers, engineers, racers and entrepreneurs were lured by the potential for the profound gains aerodynamics offered," wrote Paul Niedermeyer, author of "Automotive History: An Illustrated History Of Automotive Aerodynamics," on the website Curbside Classic. "The efforts to do so yielded some of the more remarkable cars ever made, even if they challenged the aesthetic assumptions of their times."Regarding the aerodynamics of a racing car, Dr. Joe David, professor of mechanical and aerospace engineering, and known as "Mr. Stock Car" at North Carolina State University, said, "Most of the horsepower generated by a racing engine is eaten up by the high-pressure air pushing the front of the car and the low-pressure air — a partial vacuum — dragging at the car from behind."However, drag cannot be the only consideration. While lift is desirable for an airplane, it can be dangerous for an automobile. In order to maintain better control for steering and braking, cars are designed so the wind exerts a downward force as their speed increases. However, increasing this downward force increases drag, which in turn increases fuel consumption and limits speed, so these two forces must be carefully balanced. 

INTRODUCTIONProject O9 is the name given to the custom designed bodykit of Bentley Continental GT.It is 3-piece bodykit with some extra aerodynamic fittings. The purpose is to reduce drag and lift.It has been designed taking values of aerodynamic tests on various vehicles done by various firms.The values have been taken from the graph plot of drag coefficient with other dimensional parameters. The purpose was to create the appealing mod with aerodynamic engineering .The bodykit includes-Airdam,splitter,side skirts,rear diffuser wake control vane etc.

Some of the features of Project O9 bodykit

FrontAn airdam is a panel that reduces ground clearance at the front of the car below the bumper. The smaller gap forces flow to locally

accelerate under the airdam reducing pressure under the car and creating downforce.Lower air volume flow to under body reduces drag due to under body roughness.

Front panels

Rear Extrusion

tailgate box cavity

Wheel blanking

Wheel arch vents

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