Streamlines (1936)

[Music] if you've ever taken a Flopper in a pool you know it feels like hitting something hard every good diver knows you must hit the water right or it won't get out of your way you must make your dive so as to cut the resistance just as a fish moves around without noticing the ocean we live near the bottom of a great ocean of air and although times thinner than water air has a force in motion that is enormous air offers a lot of resistance to anything going through it however nature makes it possible for birds to fly through the air at speeds that seem out of proportion to the size of their muscles science has found that this bird speed is a matter of shape as well as strength the streamlines of birds make a little power go a long way with this in mind Engineers study the resistance air offers to moving shapes since the earliest study of streamlines wind tunnels have been used to find out what happens when an object goes through the air a wind tunnel is simply a long tube with with a fan or powerful blower at one end a stream of air is blown through the tunnel at varying speeds in some tunnels up to 120 mph small models are placed in the windream and the action of the air currents is observed whls and eddes in the air currents around the models are studied and the amount of resistance or drag is measured by sensitive instruments in order to obtain a permanent record of resistance offered by various shapes liquid is used instead of air and it's action recorded by a motion picture camera the Paddle Wheel powered by a motor draws the liquid through this Center passage and sends it around the outer passages slots are used to eliminate whirls at the turns and create an area of Even Flow an object is placed in the liquid aluminum dust is added so that we can see clearly what happens to the current any for form cuts through the liquid as it would through Air This shape is not streamlined as the liquid strikes the front or Leading Edge pressure is built up which causes resistance then as it rolls off the rear it is thrown into spins or edies which create a suction behind the body regardless of shape some resistance is unavoidable as the liquid goes by the shape its direction of flow is changed and this change of Direction waste Power by rounding off the corners this change of direction is made more gradual so the amount of effort is decreased and resistance is cut down making the shape longer and thinner tends to cut down resistance this decreases the violence of the edies and reduces the suction in the rear with an even thinner shape the liquid flows more easily and there are fewer edies at the rear a streamline shape with blunt nose and tapering rear eases a hole with the least resistance and brings the liquid together at the rear with the least disturbance the ideal streamline follows a strict geometric design which Engineers call the parabola the length should be just about three times the greatest width such streamlining makes it easier for an object to get through the air by reducing wind resistance the higher the speed the more it helps any automobile traveling through the air meets the problem of wind resistance so Engineers set about applying the principles of streamlining to the automobile and by rounding The Contours and tapering the rear have smoothed out the flow of air around the body of the modern motorc car and smoothed out edies at the rear of course to a bird cars today might seem already well streamlined but as seem by a worm the modern Motorcar is anything but streamlined yet the bottom of a motor car represents about 20% of the surface and sets up considerable wind resistance the development of more complete streamlining for Motorcars will be the problem of Engineers of Tomorrow someday this problem will finally be solved sometime in the future the completely streamlined torpedo car may come into use elevated highways wide and level may let us go 120 M an hour but such a torpedo car on our streets today would be entirely impractical however practical streamlining has been applied with success to the finest Motorcars today with many additional advantages the streamlines of the new turret top give greater strength to the body of the car than the old box-like construction of yesterday the slanting windshields and windows cut down glare from rear and sides and make safer driving streamline fenders enclose the wheels more completely and help to keep the car clean and they protect the wheels from force of strong winds making the steering easier sloping rear panels allow for more tire and Luggage space these modern streamlines round out all details and absorb them into a good design with new Beauty and dignity of appearance this practical streamlining brings to the new automobile increased Comfort quiet convenience safety and Beauty practical streamlining brings a modern motor car into step with modern air speed styling which has real economy and [Music] efficiency