Accession Number:

AD0837294

Title:

THE EFFECT OF LENGTH-BEAM RATIO AND HYDROFOIL CONTROL ON THE TAKE-OFF CHARACTERISTICS OF HYDROFOIL CRAFT IN REGULAR HEAD SEAS.

Descriptive Note:

Final rept.,

Corporate Author:

STEVENS INST OF TECH HOBOKEN NJ DAVIDSON LAB

Personal Author(s):

• Brown, P. Ward
• Chey, Y. H.

Report Date:

1968-05-01

Pagination or Media Count:

59.0

Abstract:

A series of three hydrofoil boats differing in length-beam ratio is studied to determine motion response and added resistance during take-off in head seas. The effect of hydrofoils is simulated mechanically. The effect of automatic incidence control of the foils is considered. Motion response is shown to vary linearly with wave height, and added resistance to vary linearly with wave slope. High length-beam ratio is shown to reduce calm-water resistance and motions in waves at low speed. At take-off speeds of 50 percent and above, motions are independent of length-beam ratio, and the ratio has no effect on added resistance. When automatic control is used to increase the pitch- and heave-damping of the foils, motions are attenuated, but there is no effect on added resistance. Author

Descriptors:

• *HYDROFOILS
• HYDRODYNAMICS
• TAKEOFF
• OCEAN WAVES
• ROUGHNESS
• FRICTION
• PERFORMANCE(ENGINEERING)
• VELOCITY
• PITCH(MOTION)
• ATTENUATION
• RESPONSE
• HULLS(MARINE)
• DAMPING
• TEST METHODS
• MATHEMATICAL MODELS
• AUTOMATIC PILOTS
• MODEL TESTS

Subject Categories:

• Marine Engineering
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE