The pressure ratio required for a turbocharger centrifugal compressor increases with internal combustion engine power density. High pressure ratio causes a transonic flow field at the impeller inducer. Transonic flow ...The pressure ratio required for a turbocharger centrifugal compressor increases with internal combustion engine power density. High pressure ratio causes a transonic flow field at the impeller inducer. Transonic flow narrows the stable flow range and de-teriorates stage efficiency. In this work, an advanced high pressure ratio transonic compressor was designed. The experimental results show that the maximum pressure ratio of this turbocharger is about 4.2, the maximum efficiency is above 80% and the stable flow range at the designed rotating speed is up to 34%. A turbocharger with this transonic compressor has been applied to some vehicle research actually, and improved power density by 40%.展开更多
Experiments of dense-phase pneumatic conveying of pulverized coal using nitrogen were carried out in an experimental test facility with the conveying pressure up to 4 MPa and the solid-gas ratio up to 450 kg·m-3....Experiments of dense-phase pneumatic conveying of pulverized coal using nitrogen were carried out in an experimental test facility with the conveying pressure up to 4 MPa and the solid-gas ratio up to 450 kg·m-3.The influences of conveying differential pressure,gas volume flow rate and superficial velocity on the solid-gas ratio were investigated.The Shannon entropy analysis of pressure fluctuation time series was developed to reveal the flow characteristics.Through the investigation on the distribution of Shannon entropy in different conditions,the flow stability and evolutional tendency of Shannon entropy in different regimes and regime transition processes were discovered.The relationship between Shannon entropy and flow regimes was also established.The results indicated that solid gas ratio and Shannon entropy increased with increasing conveying differential pressure.Shannon entropy was different for different flow regimes,and was able to identify the flow regimes.Shannon entropy analysis is a feasible approach to researching the characteristics of flow regimes and flow regime transitions in dense-phase pneumatic conveying under high pressure.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 50806040)Specialized Research Fund for the Doc-toral Program of Higher Education) (Grant No. 200800031075)supported by the fund from National Key Laboratory of Diesel Engine Turbocharging Technology
文摘The pressure ratio required for a turbocharger centrifugal compressor increases with internal combustion engine power density. High pressure ratio causes a transonic flow field at the impeller inducer. Transonic flow narrows the stable flow range and de-teriorates stage efficiency. In this work, an advanced high pressure ratio transonic compressor was designed. The experimental results show that the maximum pressure ratio of this turbocharger is about 4.2, the maximum efficiency is above 80% and the stable flow range at the designed rotating speed is up to 34%. A turbocharger with this transonic compressor has been applied to some vehicle research actually, and improved power density by 40%.
文摘Experiments of dense-phase pneumatic conveying of pulverized coal using nitrogen were carried out in an experimental test facility with the conveying pressure up to 4 MPa and the solid-gas ratio up to 450 kg·m-3.The influences of conveying differential pressure,gas volume flow rate and superficial velocity on the solid-gas ratio were investigated.The Shannon entropy analysis of pressure fluctuation time series was developed to reveal the flow characteristics.Through the investigation on the distribution of Shannon entropy in different conditions,the flow stability and evolutional tendency of Shannon entropy in different regimes and regime transition processes were discovered.The relationship between Shannon entropy and flow regimes was also established.The results indicated that solid gas ratio and Shannon entropy increased with increasing conveying differential pressure.Shannon entropy was different for different flow regimes,and was able to identify the flow regimes.Shannon entropy analysis is a feasible approach to researching the characteristics of flow regimes and flow regime transitions in dense-phase pneumatic conveying under high pressure.
文摘随着内燃机功率密度的提高,需要更高的增压压比.采用全三维气动设计技术,设计了最大压比为4.0的车用跨声速离心压气机(可应用于微型燃气轮机),并将此应用于某型增压器的改进.针对跨声速流动特征,分析了相应的设计原则和方法.与某型发动机的配机试验结果表明,采用新设计的离心压气机后,在额定功率下,油耗下降4.1 g/(kW.h),涡轮进口温度下降35 K.
