在半消声室内对不同转速的开式叶轮的噪声进行测量。依据在对称位置的测量的噪声信号具有一定相关性,分别对旋转噪声中的2类噪声(厚度噪声、载荷噪声),进行不同测量方位、转速和频域下的分析。分析结果表明:在开式叶轮气流的下游测量方位,由于处在湍流声源的近场区域,Leq(连续等效A声压级)噪声变小,而相应的上游位置由于受湍流噪声的辐射而Leq变大;旋转噪声的Leq随转速上升而上升,厚度噪声所占份额随转速变化有下降的趋势,载荷噪声所占份额无明显变化;在频域下也发现在8倍叶片通过频率前,2类噪声都呈急剧下降趋势,8倍叶片通过频率后,两类噪声缓慢下降,并逐渐趋向于0。
There was measurement of aerodynamic noise of open rotor in semi-anochoic room with different rotate speeds, and respectively analysis of two categories of noises ( thickness noise, load noise) in different cases of measurement positions, rotate speed and frequency domain. Noise signals, acquired by sound pressure sensors in symmetric positions,have the some extent cor- relation, so use the correlation to analyze noise. The Analysis is able to indicate following statements. Leq of the downstream area become smaller than Loq in symmetric position of the upstream area because of different influences between near position and far position caused by turbulence noise. Leq of aerodynamic noise become stronger when rotate speed rising, simuhaneously the propor- tion of thickness noise in gross noise become smaller, and the proportion of load noise in gross noise do not appear to change obvi- ously. The two categories of noises decline sharply in the front of 8 times BPF( blade passing frequency) respectively, and decline slowly behind 8 times, then tend to zero.