STUDY OF IMPACT LOADS AND MOTIONS OF GROUND EFFECT MACHINES
Abstract
Results are presented of a study of the dynamic loads and motions of a hypothetical 200 ft. Ground Effect Machine with a configuration corresponding to DTMB Model 448. Operations over (and landings into) sinusoidal waves were simulated on an analogue computer, and compared with towing tank results for the same configuration. The study was implemented by simplified versions of existing GEM theory for hovering operation. No allowances were made for the effect of forward speed on ground effect lift. T HE DEQUATE SIMULATION OF THE AERIAL MOTIONS WAS CONSIDERED A NECESSARY PRELIMINARY TO DYNAMICALLY SIMILAR LINEAR AND ANGULAR VELOCITIES AT WATER IMPACT. The water forc s at impact were calculated through use of an immersing wedge theory of Wagner and Pierson, Pierson, J. D., The Penetration of a Fluid Surface by a Wedge, and the assumption that the interaction of the air curtain, air cushion, peripheral jets, water surface, and the essentially flat bottom of the GEM would be equivalent to a wedge with a deadrise of 10 degrees. The agreement of the simulatio wit the model motions over waves was good. The water impact comparisons show that further study is required. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1961
- Accession Number
- AD0275133
Entities
People
- J.e. Loos
- R.m. Hopkins
Organizations
- General Dynamics