Accession Number : ADA288941

Title :   Directional Stability Tests of a 30 Degree Deadrise Prismatic Planing Hull.

Descriptive Note : Final rept.,

Corporate Author : STEVENS INST OF TECH HOBOKEN NJ DAVIDSON LAB

Personal Author(s) : Brown, P. W. ; Klosinski, Walter E.

PDF Url : ADA288941

Report Date : DEC 1994

Pagination or Media Count : 216

Abstract : This is the second of four reports on research designed to obtain basic hydrodynamic information about planing hulls through the use of captive model tests. The information is to be used for the general study of dynamic stability while underway, course keeping, turning and maneuvering, etc. The models tested were of idealized patrol boats having an LBP of 100 ft., a beam of 20 ft., and a displacement of 100 long tons. The models had prismatic hull forms with 10, 20, and 30 degrees of deadrise. The report presents the results of tests on the 30 degree of deadrise hull. Most of the data is for the unappended hull. Straight course and rotating arm tests were conducted at three speeds Cv = 1.5, 3.0, and 4.01, three angular velocities LIR = 0, 0.117, and 0.234 and a single beam loading Cv = 0.4375. The tests covered the following angular parameter ranges. Trim: -2 to 6 degrees, roll: -10 to 20 degrees, and yaw: -15 to 15 degrees. Twin rudders were fined during the straight course tests at zero degrees of roll and yaw, and three degrees of trim. The effect of rudder deflection from -20 to 20 degrees was investigated. Measurements were made of the drag and side forces, and the roll, pitch, and yaw moments. Draft was recorded. Underwater photographs were taken, and the wetted lengths and areas determined from these photographs. Video recordings were made of all runs. The data are presented in extensive tables, in wind axes and body axes, and in both dimentional and non-dimensional form.

Descriptors :   *STABILITY, *HULLS(MARINE), *HYDRODYNAMICS, VELOCITY, ANGLES, YAW, DYNAMICS, PARAMETERS, WIND, REPORTS, DEFLECTION, TEST METHODS, MOMENTS, WETTING, LENGTH, AXES, RUDDERS, DRAG, PATROL CRAFT, HULLS(STRUCTURES), ANGULAR MOTION, CAPTIVE TESTS, PHOTOGRAPHS, PLANING SURFACES, TURNING(MANEUVERING), UNDERWATER, VIDEO RECORDING.

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE