针对某轿车在怠速、急加速过程中车内出现异响的现象,通过尾管噪声测试和模态测试,判断其排气二阶噪声及怠速共振噪声是主要原因.采用共振消声结构,降低二阶低频及共振噪声成分,采用芦弗管结构,降低高频气流再生噪声成分,并使用GT-Power软件对发动机加速瞬态尾管噪声进行模拟,实现消声器结构的改进.试验结果表明,改进后的消声器,在车辆启动和急加速时瞬时尾管噪声最大值降低明显,达到主观评价要求.%Aiming at the interior abnormal noise during idling and rapid acceleration of a car, the main noise sources, which are the second order and resonance noises, are identified by the tailpipe noise measurement and modal test respectively. A resonant chamber is designed to lower the sound level of the second order and resonant frequencies. A pinch-can structure is used to reduce the high frequency flow noise. And the tailpipe noise at transient accelerating is simulated by GT-Power software. The test results show that the maximum values of transient tailpipe noises at idling and rapid acceleration can be reduced by 11.7 dB(A) and 8 dB(A) respectively.
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