[aerohead]

One of my aviation books had some info on Coanda.
Henri Coanda,Romanian inventor,built,and presented an aircraft of his design in Paris,1910.
The aircraft was powered by a 50-hp engine directly coupled to a centrifugal compressor.
The compressor developed 450-pounds of thrust,not enough to propel the plane.It never flew.
In 1911,Coanda presented a second aircraft of 150 hp turning a conventional 4-blade tractor propeller.This plane also failed to fly.
In 1912 Coanda relocated to England where he would work for Bristol Aircraft.
Coanda had great gifts with airframe ingenuity and construction.
Coanda is a cult figure among UFO conspiracy circles,and claims are made to the efficacy of disk aircraft constructed in late WW-II Germany which exploited the Coanda 'effect.'
PS I quickly ran the drag force for an 18-wheeler of Cd 0.70 and 95 square feet of frontal area at 70 mph at standard temp and baro pressure and came up with 957 pounds of aero drag.Using the centrifugal compressor,over 100-hp would be required to create an opposing air jet to cancel the drag.More to compensate for rolling resistance.
Reshaping the back of the trailer would accomplish the same thing with zero horsepower,although,certainly,it opens up other issues.