SYSTEM FOR MEASURING A VARIATION PRESSURE INDUCED BY A SHIP PROPELLER CAVITATION

摘要

Background of invention 1. The present invention relates to a kind of invention fields of system, are used for a fluctuation pressure caused by the cavitation erosion by a marine propeller for the reason of measurement is a main ship hull vibration. ;As well known, the cavitation erosion of one ship's propeller, its main cause as ship hull vibration, it is the sudden change in the cross section of flowing water, or when the direction of flow change, one chamber is formed about in cavitation erosion, (cavitation test), by leading to a noise (vibration) in a part of load (fractional load) and leading to the corrosion in one side vehicle in a heavy duty, the phenomenon that according to a characteristic value of the appearance for the cavitation erosion for generating cavitation erosion by model car, is caused) by be used to support be provided with the variable pressure plate an of pressure sensor measuring device form ought move up and down and for one signal of amplification as shown in the figure an amplifier;Since the fluctuation pressure plate of these measuring devices is positioned above, propeller and fluctuation pressure, its pressure sensor for passing through the necessity with the vibration for minimizing measuring device by propeller cavitation, it is weak signal, when estimating the association between model line and actual vessel, the measurement for being used simultaneously in the actual pressure of actual vessel is minimized error by measuring system by system. However, not obtaining such implement. ;To solve the above-mentioned problems, the present invention is a kind of for reproducing the method for a flat plate variable pressure plate in a model propeller, is separated by 62.5 millimeters of six pressure converters of installation,;In a real ship, a pressure sensor is installed in the bottom of shell, is stored in a tape recorder by an amplifier by the signal that pressure sensor measures. After experiment, a fast Fourier transform analyzer can be used in a laboratory and execute frequency response analysis, in order to measure the accuracy of measurement during the experiment, it is necessary to observe time signal and substantially carry out frequency response analysis by using oscillograph, amplify first and second amplitude to be easily adjusted zero point. Waterproof cloth can be smoothly carried out under high pressure and up/down is mobile, prevents self vibration and command range, manufacture NACA 16-021 section configurations, therefore improve traditional problem.