涡轮增压柴油机进气消声器设计与试验验证

Intake Silencer Design and Test Verification of a Turbocharged Diesel Engine

涡轮增压柴油机噪声测试表明,进气噪声为整机最主要的噪声源,压气机产生的高频噪声对总声级贡献最大.根据进气噪声频谱特性,设计了两种组合式空气过滤消声器,然后使用有限元法结合自动匹配层(AML)计算消声器的插入损失,两种组合式空气过滤消声器的插入损失分别为23.8 dB和25.1 dB.为分析消声器结构对进气阻力的影响,使用计算流体动力学(CFD)方法计算了原空气过滤消声器和两种组合式空气过滤消声器的阻力损失,两种组合式空气过滤消声器均满足阻力损失不超过8 kPa限制要求.最后开展了柴油机配机性能试验,试验结果表明:两种组合式空气过滤消声器的插入损失分别达到23.6 dB和24.6 dB,且没有增加发动机的功率损失.

The noise measurement for a turbocharged diesel engine indicated that the intake noise is the main noise source of the engine,and the high-frequency noise generated by the compressor is the primary contributor to the total sound level.According to the frequency spectrum of the intake noise,two combined air filtering silencers were designed.Then the insertion loss was calculated using the finite element method and combining the automatic matching layer(AML).The calculated results show that the insertion loss of the two combined air filtering silencers are 23.8 d B and 25.1 d B,respectively.In order to investigate the effect of silencer structure on the intake resistance,a computational fluid dynamics(CFD)simulation was conducted to calculate the flow resistance loss of the original air filtering silencer and the two combined air filtering silencers,and the calculated results show that the both combined air filtering silencers meet the 8 kPa limit.Finally,a performance test of the diesel engine was carried out,and the measurements show that the insertion loss of the two combined air filtering silencers are 23.6 dB and 24.6 d B,respectively,without increase of the engine power loss.