Propeller dynamometer load device for measuring background noise of circulating water tank

Abstract

The invention relates to a propeller dynamometer load device for measuring background noise of a circulating water tank, and the device comprises a magnetic powder brake, a shell, a screw, a screw shell and a sucker; the magnetic powder brake is mounted on a propeller dynamometer shaft and provides a constant torque; the shell is used for wrapping a shell of the magnetic powder brake and sealing the magnetic powder brake in the shell, four wing-shaped supports extending out of the shell are connected with the suction cup through screws respectively, and the lengths of the screws are adjusted through threads so as to adapt to circulating water tanks with different sections; and a screw shell is wrapped outside the screw.

Description

technical field [0001] The invention relates to a propeller dynamic instrument load device, which belongs to the field of ships and marine engineering. Background technique [0002] The design of propellers or pump impellers of ships and underwater vehicles often needs to meet certain noise indicators, which requires the underwater noise prediction of propellers or pump impellers during the design process. At present, the commonly used underwater noise prediction methods for propellers or impellers include numerical prediction methods and model test prediction methods, among which the model test method is a more recognized underwater noise prediction method. [0003] Propeller noise model tests are generally carried out in circulating water tanks. The circulating water tank is often made into a vertical back-shaped pipeline structure, with a general height of about 10 meters. The bottom horizontal pipeline pushes the water to flow in the back-shaped pipeline through the wat...

AI Technical Summary

Problems solved by technology

[0006] From the above analysis, it can be found that the current propeller noise model test based on the circulating water tank has disadvantages in the background noise measurement step, that is, the load of the propeller dynamometer is different from the load with the propeller model.

The current method of measuring the background noise of circulating water tanks may lead to an underestimation of the background noise, and then the test results that do not meet the requirement of 6 decibels higher than the background noise are also considered to have a sufficient signal-to-noise ratio.

On the other hand, it may also cause the extra noise generated by the increased load of the propeller dynamometer motor to be attributed to the propeller noise, thus overestimating the propeller noise

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