Cavity resonance noise of passenger car tires is generated by interacting excitation between a tire structure and the fill gas (air), and generally lies in a frequency range of 200?250 Hz. As such, this noise is stron...Cavity resonance noise of passenger car tires is generated by interacting excitation between a tire structure and the fill gas (air), and generally lies in a frequency range of 200?250 Hz. As such, this noise is strongly perceived and may be a serious source of driver annoyance. Thus, many studies regarding the cavity noise mechanism and its reduction have already been conducted. In this work, a vibro-acoustic coupled analysis was conducted between a tire structure and air cavity. Using this analysis, we can more accurately simulate the tire noise performance in the region of the cavity resonance frequency. An analysis of the effects of variation of tire contour design factors was conducted, using design-of-experiments methods. Finally, a multi-objective optimization was performed using in-house codes to reduce the cavity noise level while minimizing the loss of other performances, such as diminished ride comfort and handling caused by the variations of contour. As a result of this optimization, an optimized contour shape was derived, which satisfied the multi-objective performances.展开更多
Gas with high pressure is widely used at present as fuel storage mode for different hydrogen vehicles. Differenttypes of materials are used for constructing these hydrogen pressure vessels. An aluminum lined vessel an...Gas with high pressure is widely used at present as fuel storage mode for different hydrogen vehicles. Differenttypes of materials are used for constructing these hydrogen pressure vessels. An aluminum lined vessel and typicallycarbon fiber reinforced plastic (CFRP) materials are commercially used in hydrogen vessels. An aluminumlined vessel is easy to construct and posses high thermal conductivity compared to other commercially availablevessels. However, compared to CFRP lined vessel, it has low strength capacity and safety factors. Therefore,nowadays, CFRP lined vessels are becoming more popular in hydrogen vehicles. Moreover, CFRP lined vesselhas an advantage of light weight. CFRP, although, has many desirable properties in reducing the weight and inincreasing the strength, it is also necessary to keep the material temperature below 85 ℃ for maintaining stringentsafety requirements. While filling process occurs, the temperature can be exceeded due to the compression worksof the gas flow. Therefore, it is very important to optimize the hydrogen filling system to avoid the crossing of thecritical limit of the temperature rise. Computer-aided simulation has been conducted to characterize the hydrogenfilling to optimize the technique. Three types of hydrogen vessels with different volumes have been analyzed foroptimizing the charging characteristics of hydrogen to test vessels. Gas temperatures are measured inside representativevessels in the supply reservoirs (H2 storages) and at the inlet to the test tank during filling.展开更多
文摘Cavity resonance noise of passenger car tires is generated by interacting excitation between a tire structure and the fill gas (air), and generally lies in a frequency range of 200?250 Hz. As such, this noise is strongly perceived and may be a serious source of driver annoyance. Thus, many studies regarding the cavity noise mechanism and its reduction have already been conducted. In this work, a vibro-acoustic coupled analysis was conducted between a tire structure and air cavity. Using this analysis, we can more accurately simulate the tire noise performance in the region of the cavity resonance frequency. An analysis of the effects of variation of tire contour design factors was conducted, using design-of-experiments methods. Finally, a multi-objective optimization was performed using in-house codes to reduce the cavity noise level while minimizing the loss of other performances, such as diminished ride comfort and handling caused by the variations of contour. As a result of this optimization, an optimized contour shape was derived, which satisfied the multi-objective performances.
文摘Gas with high pressure is widely used at present as fuel storage mode for different hydrogen vehicles. Differenttypes of materials are used for constructing these hydrogen pressure vessels. An aluminum lined vessel and typicallycarbon fiber reinforced plastic (CFRP) materials are commercially used in hydrogen vessels. An aluminumlined vessel is easy to construct and posses high thermal conductivity compared to other commercially availablevessels. However, compared to CFRP lined vessel, it has low strength capacity and safety factors. Therefore,nowadays, CFRP lined vessels are becoming more popular in hydrogen vehicles. Moreover, CFRP lined vesselhas an advantage of light weight. CFRP, although, has many desirable properties in reducing the weight and inincreasing the strength, it is also necessary to keep the material temperature below 85 ℃ for maintaining stringentsafety requirements. While filling process occurs, the temperature can be exceeded due to the compression worksof the gas flow. Therefore, it is very important to optimize the hydrogen filling system to avoid the crossing of thecritical limit of the temperature rise. Computer-aided simulation has been conducted to characterize the hydrogenfilling to optimize the technique. Three types of hydrogen vessels with different volumes have been analyzed foroptimizing the charging characteristics of hydrogen to test vessels. Gas temperatures are measured inside representativevessels in the supply reservoirs (H2 storages) and at the inlet to the test tank during filling.
