Accession Number : AD0283666

Title :   AN EXPERIMENTAL STUDY OF THE LONGITUDINAL SEAKEEPING CHARACTERISTICS OF THE BUREAU OF SHIPS HYDROSKIMMER

Corporate Author : STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB

Personal Author(s) : CHEN,S.C.Y. ; KOWALSKI,T.

Report Date : JUN 1962

Pagination or Media Count : 1

Abstract : A 1/15-scale model of a 20-ton BuShips Hydroskimmer design was tested to determine the longitudinal seakeeping characteristics in a State-3 head sea condition. The model was tested at several speeds up to a max of 46 knots (fullsize) with and without a simulated displacement sensitive pitch control. The studies indicated that, when hovering over waves, the uncontrolled vehicle was unstable in pitch. When running at 46 knots in a Sea State-3, the pitch stability was satisfactory. No significant or consistent attenuation in drag, pitch, and heave motions or accelerations were achieved by the use of simulated pitch control when running in a seaway. The motion and impact forces on the model were somewhat decreased when the sea state was reduced from a State-3 Sea to a State-2 Sea. In lowspeed tests, there was good correlation between the pitch response amplitude operators obtained in regular and irregular wave tests. It appears that the present Hydroskimmer configuration, running at the intended ground clearance, cannot achieve acceptable operation in a State-3 Sea. Improved hydrodynamic performance might be attained by increasing the hull clearance, by increasing the deadrise at the bow, or by using flexible nozzles in the bow area. (Author)

Descriptors :   *FLYING PLATFORMS, *GROUND EFFECT, ACCELERATION, AERODYNAMIC CHARACTERISTICS, DRAG, GAS FLOW, HYDRODYNAMICS, JETS, LIFT, MODEL TESTS, PITCH (MATERIAL), PITCH (MOTION), PRESSURE, SHIP MODELS, SHIPS, STABILITY

Distribution Statement : APPROVED FOR PUBLIC RELEASE