Section 1 Introduction
Clasification Society 2024 - Version 9.40
Clasifications Register Guidance Information - Ship Vibration and Noise Guidance Notes - Chapter 10 Hull Surface Pressures - Section 1 Introduction

Section 1 Introduction

1.1 Hull surface pressures are generated by the action of the propeller operating in a non-uniform wake field. At normal tip clearances, the non-cavitating propeller tends to produce low hull pressures which have a dominant blade rate content. Cavitation occurs on most commercial propellers in the service speed/power range. Pressure signals typical of cavitating propellers show increased amplitudes at blade rate and distinct components at multiples of blade rate, typically up to 5 times blade rate. Two types of excitation are encountered: broadband and discrete harmonic.

Susceptibility to troublesome levels of hull surface pressures depends on ship speed in association with thrust required, after body hull form, appendage design and clearances around the propeller.

The effect of excitation from tip vortices on any unusual length of the afterbody of the ship beyond the propeller station needs careful consideration.

Parent topic: Chapter 10 Hull Surface Pressures
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