Accession Number : AD0499390

Title :   The Theoretical Vertical Motions of a Controlled Hydrofoil in Waves.

Descriptive Note : Technical rept.,

Corporate Author : BATH IRON WORKS CORP ME*

Personal Author(s) : Amster, W. H. ; Lavagnino, A.

Report Date : JUL 1952

Pagination or Media Count : 66

Abstract : The steady-state responses of the vertical motions of an automatically controlled single foil hydrofoil operating in waves with a length-height ratio of 13 are investigated. The effects of orbital motions are incorporated into the analysis in conjunction with straight proportional control, proportional control with anticipation by sensing forward of the control foil, and proportional plus derivative control. The limitations of the analysis are discussed. Phase lag is the critical factor in proportional control. The phase lag can be decreased by sensing forward of the control foil but the optimum location varies with sea conditions. With proportional plus derivative control the phase lag can be decreased and it is primarily dependent upon the parameters of the system. (Author)

Descriptors :   (*HYDROFOILS, PITCH(MOTION)), FLUID DYNAMICS, HYDRODYNAMICS, MOTION, THEORY, LIFT, VELOCITY, BUOYANCY, DYNAMICS, EQUATIONS OF MOTION, AUTOMATIC PILOTS, CONTROL SYSTEMS, MATHEMATICAL ANALYSIS, SERVOMECHANISMS, RESPONSE, TIME.

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE