Method and apparatus for reducing air drag on truck type wheeled vehicles

An air screen producing device mountable on a draft vehicle adapted to tow a trailer vehicle therebehind in a forward direction of movement of said draft and trailer vehicles relative to ground, said draft vehicle having an upright rear wall and said trailer vehicle having an upright front wall spaced rearwardly from said rear wall to provide an open space therebetween, said air screen producing device including tubular air passageway means on said draft vehicle and having front and rear ends with respect to said forward direction, said air passageway means including an air inlet opening at said front end and an air outlet opening at said rear end and adjacent said rear wall of said draft vehicle, said air outlet opening being an elongate narrow opening having major and minor dimensions, said tubular passageway means including air pressurizing means between said inlet and outlet openings for pressurizing ambient air entering said inlet opening during movement of said draft and trailer vehicles in said forward direction at a given velocity relative to ground, said pressurizing means providing for said pressurized air to be discharged from said elongate narrow outlet opening as a screen of air having a velocity higher than the velocity of ambient air relative to said draft and trailer vehicles moving at said given velocity, said front wall of said trailer vehicle including edge means having a given length, said air outlet opening facing said edge means with said major dimension of said outlet opening parallel to said edge means, whereby said screen of higher velocity air flows from said outlet opening rearwardly across said open space to said edge means and parallel thereto, and said major dimension of said outlet opening providing for said screen of air jet said edge means to extend along said given length of said edge means.