The introduction of acoustical energy into the air in the annular bypass passageway results in the generation in that passageway of fan noise which would be created in the bypass duct of a jet engine employing the nozzle assembly being tested under actual operating conditions. A method for ...
This brings up another complication in the measurement of noise. We do not generally respond in the same way to different types of noise, even though they may be equal in sound level. For example, a symphony orchestra playing middle C at 120 dB(A) and a jet engine running at an equal...
With the drivers loaded, the software will back the fan speed down to a minimal level and (I'm presuming) control the speed as needed from there.I had to sit through an hour of SmartStart assisted OS loading to arrive at this. Once my OS booted and the HP drivers loaded, the fan ...
This effect was robust; it was independent of the presence of hit-KR, even though hit-KR generally lowered the overall level of perceived workload. The results provide the initial experimental demonstration that perceived workload is a sensitive measure of the effects of aircraft noise in ...
In the case of airports, jet engines may be modified to reduce their noise level, or insulation(隔音) from air traffic noise may be provided by the purchase of land around airports or the insulation of buildings. One estimate is that ＄5.7 billion would be required to equip all existing je...
noise level 噪声级;噪声电平 signal to noise ratio 信噪比,信号噪声比 background noise 背景噪声 big noise 有响的人,名人;耸人听闻的声明 phase noise 相位噪声 random noise 随机噪声;不规则噪声 environmental noise 环境噪声 gaussian noise 高斯噪声 make a noise 吵闹,喧;众人谈论或注意的对象 noise elimina...
(A) Self-noise spectrum level; (B) Increase of level. Of course, the self-noise levels of modern naval ships have considerably been reduced in comparison with those mentioned earlier. How to determine the self-noise levels for a specific communication sonar is quite complicated and difficult, ...
Situation Level (decibels) Effect Jet engine (close by)* 140 Harmful to hearing Jet takeoff* 130 Propeller aircraft* 120 Live rock band 110 Risk of hearing loss Jackhammer 100 Heavy-duty truck 90 Private car; business office 70 Probably no risk of permanent damage to hearing Wooded resi...
Electromagnetic compatibility is achieved by reducing the interference below the level that disrupts the proper operation of the electronic system or subsy... A Keshtkar,A Maghoul,A Kalantarnia,... - 《Applied Mechanics & Materials》 被引量: 3发表: 2011年 Investigation of electric field distribu...
A fluidic device for reduction of the sound level of the jet engine according to the invention is applied to the nacelle of jet engine2of FIG. 1. This device is arranged, for example, with reference to the more or less cylindrical exterior wall20(exterior hood) of the nacelle and which ...