Automobile Streamlining: “Taking the Air” 1941 Chevrolet Division General Motors Corporation

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“STUDIES IN STREAMLINING FROM THE DAYS OF HORATIO PHILLIPS TO MODERN TIMES. EVOLUTION OF AUTOMOBILE FROM ITS BEGINNING TO PRESENT STREAMLINED SHAPE IS EXEMPLIFIED IN THE 1941 CHEVROLET.”

NEW VERSION with improved video & sound:

Public domain film from the Prelinger Archive, slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).

Horatio Frederick Phillips (born 1845 in Streatham – 1924) was an early aviation pioneer from the United Kingdom. He was famous for building multiplane flying machines with many more sets of lifting surfaces than would be normal on modern aircraft. However he made a more lasting contribution to aeronautics in his work on aerofoil design…

Aerofoils

Phillips devised a wind tunnel in which he studied a wide variety of aerofoil shapes for use in providing lift. The tunnel was unusual in that the gas flow was provided by steam rather than air.

By 1884 he was able to register his first patent, and more were to follow. He demonstrated the truth of George Cayley’s idea that giving the upper surface greater curvature than the lower accelerates the upper airflow, reducing pressure above the wing and so creating lift…

In fluid dynamics, drag (sometimes called air resistance or fluid resistance) refers to forces which act on a solid object in the direction of the relative fluid flow velocity. Unlike other resistive forces, such as dry friction, which is nearly independent of velocity, drag forces depend on velocity.

Drag forces always decrease fluid velocity relative to the solid object in the fluid’s path…

Examples of drag

Examples of drag include the component of the net aerodynamic or hydrodynamic force acting opposite to the direction of the movement of the solid object relative to the Earth as for cars, aircraft and boat hulls; or acting in the same geographical direction of motion as the solid, as for a sails on a down wind sail boat, or in intermediate directions on a sail depending on points of sail. In the case of viscous drag of fluid in a pipe, drag force on the immobile pipe decreases fluid velocity relative to the pipe.

Types of drag

Types of drag are generally divided into the following categories:

– parasitic drag, consisting of
— form drag,
— skin friction,
— interference drag,
– lift-induced drag, and
– wave drag (aerodynamics) or wave resistance (ship hydrodynamics).

The phrase parasitic drag is mainly used in aerodynamics, since for lifting wings drag is in general small compared to lift. For flow around bluff bodies, drag is most often dominating, and then the qualifier “parasitic” is meaningless. Form drag, skin friction and interference drag on bluff bodies are not coined as being elements of “parasitic drag”, but directly as elements of drag.
Further, lift-induced drag is only relevant when wings or a lifting body are present, and is therefore usually discussed either in the aviation perspective of drag, or in the design of either semi-planing or planing hulls. Wave drag occurs when a solid object is moving through a fluid at or near the speed of sound in that fluid—or in case there is a freely-moving fluid surface with surface waves radiating from the object, e.g. from a ship…

Parasitic drag (also called parasite drag) is drag caused by moving a solid object through a fluid. Parasitic drag is made up of multiple components including viscous pressure drag (form drag), and drag due to surface roughness (skin friction drag). Additionally, the presence of multiple bodies in relative proximity may incur so called interference drag, which is sometimes described as a component of parasitic drag.

In aviation, induced drag tends to be greater at lower speeds because a high angle of attack is required to maintain lift, creating more drag. However, as speed increases the induced drag becomes much less, but parasitic drag increases because the fluid is flowing faster around protruding objects increasing friction or drag. At even higher speeds in the transonic, wave drag enters the picture. Each of these forms of drag changes in proportion to the others based on speed. The combined overall drag curve therefore shows a minimum at some airspeed – an aircraft flying at this speed will be at or close to its optimal efficiency. Pilots will use this speed to maximize endurance (minimum fuel consumption), or maximize gliding range in the event of an engine failure…