利用STAR-CCM+三维流体分析软件结合声学仿真软件GT-power对某1.5 T SUV排气消音器进行联合模拟仿真,考察其温度、压力、速度场,对压力损失进行评估,并根据企业要求针对背压提出优化方案,在噪声基本不变的前提下,降低整体背压至45 k Pa...利用STAR-CCM+三维流体分析软件结合声学仿真软件GT-power对某1.5 T SUV排气消音器进行联合模拟仿真,考察其温度、压力、速度场,对压力损失进行评估,并根据企业要求针对背压提出优化方案,在噪声基本不变的前提下,降低整体背压至45 k Pa以下。经台架试验验证,优化方案达到了预期效果,对排气系统起到了有益的改善作用。展开更多
2015年改装车展,宝马汇集了众多具有革命性的BMW改装配件,为人们展示了宝马强大实力的拓展空间。6月12日,BMW携诸多革命性创新产品亮相2015中国国际改装车展,包括性能与美学的终极诠释BMW M performance高性能附件、即将改变日常驾驶的...2015年改装车展,宝马汇集了众多具有革命性的BMW改装配件,为人们展示了宝马强大实力的拓展空间。6月12日,BMW携诸多革命性创新产品亮相2015中国国际改装车展,包括性能与美学的终极诠释BMW M performance高性能附件、即将改变日常驾驶的创新科技BMW M Performance+(驾驶分析仪)。展开更多
In marine engine exhaust silencing systems, the presence of exhaust gas flow influences the sound propagation inside the systems and the acoustic attenuation performance of silencers. In order to investigate the effec...In marine engine exhaust silencing systems, the presence of exhaust gas flow influences the sound propagation inside the systems and the acoustic attenuation performance of silencers. In order to investigate the effects of three-dimensional gas flow and acoustic damping on the acoustic attenuation characteristics of marine engine exhaust silencers, a dual reciprocity boundary element method (DRBEM) was developed. The acoustic governing equation in three-dimensional potential flow was derived first, and then the DRBEM numerical procedure is given. Compared to the conventional boundary element method (CBEM), the DRBEM considers the second order terms of flow Mach number in the acoustic governing equation, so it is suitable for the cases with higher Mach number subsonic flow. For complex exhaust silencers, it is difficult to apply the single-domain boundary element method, so a substructure approach based on the dual reciprocity boundary element method is presented. The experiments for measuring transmission loss of silencers are conducted, and the experimental setup and measurements are explained. The transmission loss of a single expansion chamber silencer with extended inlet and outlet were predicted by DRBEM and compared with the measurements. The good agreements between predictions and measurements are observed, which demonstrated that the derived acoustic governing equation and the DRBEM numerical procedure in the present study are correct.展开更多
文摘利用STAR-CCM+三维流体分析软件结合声学仿真软件GT-power对某1.5 T SUV排气消音器进行联合模拟仿真,考察其温度、压力、速度场,对压力损失进行评估,并根据企业要求针对背压提出优化方案,在噪声基本不变的前提下,降低整体背压至45 k Pa以下。经台架试验验证,优化方案达到了预期效果,对排气系统起到了有益的改善作用。
文摘2015年改装车展,宝马汇集了众多具有革命性的BMW改装配件,为人们展示了宝马强大实力的拓展空间。6月12日,BMW携诸多革命性创新产品亮相2015中国国际改装车展,包括性能与美学的终极诠释BMW M performance高性能附件、即将改变日常驾驶的创新科技BMW M Performance+(驾驶分析仪)。
基金the National Natural Science Foundation of China under Grant No.10474016.
文摘In marine engine exhaust silencing systems, the presence of exhaust gas flow influences the sound propagation inside the systems and the acoustic attenuation performance of silencers. In order to investigate the effects of three-dimensional gas flow and acoustic damping on the acoustic attenuation characteristics of marine engine exhaust silencers, a dual reciprocity boundary element method (DRBEM) was developed. The acoustic governing equation in three-dimensional potential flow was derived first, and then the DRBEM numerical procedure is given. Compared to the conventional boundary element method (CBEM), the DRBEM considers the second order terms of flow Mach number in the acoustic governing equation, so it is suitable for the cases with higher Mach number subsonic flow. For complex exhaust silencers, it is difficult to apply the single-domain boundary element method, so a substructure approach based on the dual reciprocity boundary element method is presented. The experiments for measuring transmission loss of silencers are conducted, and the experimental setup and measurements are explained. The transmission loss of a single expansion chamber silencer with extended inlet and outlet were predicted by DRBEM and compared with the measurements. The good agreements between predictions and measurements are observed, which demonstrated that the derived acoustic governing equation and the DRBEM numerical procedure in the present study are correct.
