Accession Number:

ADA379808

Title:

The Planing Characteristics of a Surface Having a Basic Angle of Dead Rise of 40 deg and Horizontal Chine Flare

Descriptive Note:

Technical note

Corporate Author:

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON DC

Personal Author(s):

• Blanchard, Ulysse J.

Report Date:

1952-12-01

Pagination or Media Count:

29.0

Abstract:

In order to determine the effects of increasing the angle of dead rise on the planing characteristics of horizontally flared prismatic surfaces, an experimental investigation has been conducted with a surface having a basic angle of dead rise of 40 deg and horizontal chine flare. Wetted length, resistance, center-of-pressure location, and draft were determined for speed coefficients up to 25.0 and trims up to 30 deg. Beamloading coefficients ranged from 085 to 87.33 and keel-weeted-length-beam ratios extended generally to 7.0 and, in some cases, to higher values whenever conditions of load and spray permitted. The data show that for a given trim the planing characteristics depend principally on lift coefficient. The experimental variation of the difference between chine and keel wetted lengths with trim has the same general trend as theory. An increase in angle of dead rise from 200 NACA TN 2804 to 400 decreased the ratio of center-of-pressure location to mean wetted length and the extent of the pile-up of water but increased the friction drag. At trims of 24 deg and greater, friction drag is negligible and the resistances for those trims may be assumed equal to the load times the tangent of the trim angle.

Descriptors:

• *HYDRODYNAMIC CHARACTERISTICS
• *SHIP HULLS
• *PLANING SURFACES
• TRIM ANGLE
• SEAPLANES
• HYDRODYNAMIC CONTROL SURFACES

Subject Categories:

• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE