Complete anechoic chamber for rotor noise test

Abstract

The invention discloses a complete anechoic chamber for a rotor noise test, and belongs to the technical field of helicopter rotor tests. The complete anechoic chamber is characterized in that an air inlet is formed in the upper part of the anechoic chamber; an air exhaust is formed in the lower part of the anechoic chamber; a rotor test rig is fixed in the center of the air exhaust duct and stretches into the anechoic chamber; the air inlet and the air exhaust are annular; sound-absorbing linings are installed on the inner walls of an air inlet duct and an air exhaust duct; annular cylindrical array silencers are arranged at each of the air inlet and the air exhaust; a rotor center is positioned in a central position in the height direction of the anechoic chamber; the silencers at the air inlet and the air exhaust of the anechoic chamber and the sound-absorbing linings on the inlet duct and the air exhaust duct of the anechoic chamber use metal surfaces. Different from the conventional complete anechoic chamber, the complete anechoic chamber provided by the invention is provided with an airflow channel for large-flow airflow to pass through and takes effective sound-slickening and sound-insulating measures on the airflow channel, so that a free sound field is formed in the anechoic chamber and leaking noises meet environment-friendly requirements; a high-power rotor test rig is arranged inside the anechoic chamber and a rotor with relatively large size can run in the anechoic chamber, so that a noise test is wider in range and better in effect.

Description

technical field [0001] The invention belongs to the technical field of helicopter rotor tests, in particular to a full anechoic chamber for rotor noise tests. Background technique [0002] The anechoic chamber is a specially designed and manufactured basic audio acoustics laboratory. In order to accurately measure the characteristics of the sound source, the sound source should be placed in an ideal space without interference. Such a space is called a "free sound field". People establish an approximate free sound field indoors, which is an "anechoic room". [0003] The shape of the anechoic chamber is mostly square or rectangular. The anechoic room usually adopts a fully enclosed structure, and the sound insulation door is set up to enter and exit. [0004] In the prior art, the patent application number is 200910046035.8, the patent name: full anechoic chamber with ultra-low background noise, and the application date: 2009.2.10 is recorded in the document. [0005] The r...

AI Technical Summary

Problems solved by technology

Ordinary full anechoic chambers cannot support heavy high-power test benches because all of them are equipped with sound-absorbing materials. In addition, when performing rotor tests, a large flow of air flows through the rotor paddle discs. If the anechoic chamber is designed to be closed, In the anechoic chamber, there will be air flow backflow and pressure pulsation, which will affect the test effect of the rotor test.

Images