Download or read book The Ground Effect on Lifting Propellers written by Albert Betz and published by . This book was released on 1937 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: In what follows an estimate will be made of the magnitude of the ground effect. For the two cases where the distance a of the propeller from the ground is very small, and very large, respectively, in comparison with the propeller radius r(sub o) the relations may be simply expressed. We consider first the effect of the ground, assuming that the thrust is held constant, as may be done by a suitable change in the propeller speed.