螺旋进气道形状和位置偏差对涡流比及流量系数的影响.docx

螺旋进气道形状和位置偏差对涡流比及流量系数的影响刘书亮1 , 沈捷2 , 刘德新1 , 李玉峰1 , 卓松芳2 ,邱瑞兴2 , 任立红1 , 肖浩栋1(1 . 天津大学内燃机燃烧学国家重点实验室 , 天津 300072 ; 2 . 广西玉柴机器股份有限公司 , 玉林 537005)摘 要 :螺旋进气道在铸造和机械加工过程中会出现各种各样的偏差 ,从而影响直喷式柴油机的动力经济性和排放特性 . 作者设计了几种机构来模拟不同类型的偏差 ,如带有倾斜误差的进气道 、带有纵向胀大误差的进气道以及 带有偏心误差的进气道等 . 在稳流试验台上检测气道的流动特性 . 实验结果表明 ,倾斜气道会显著影响涡流比 . 抬高气道入口端会明显降低涡流比 ,反之则涡流比提高 ;气道胀大会使流量系数和涡流比都降低 ;当偏心出现在气道出口方向时 ,涡流比略有增加 ;当偏心出现在气道入口方向时 ,涡流比会显著降低 .关键词 :直喷式柴油机 ; 螺旋进气道 ; 形状位置偏差 ; 流量系数 ; 涡流比中图分类号 : T K21文献标识码 :A文章编号 :100628740 (2003) 0520397207An Investigation of Eff ect of Sha pe and Position Deviations of Hel ical InletPort of D I D iesel Engines on Flo w Coeff ic ient and Swirl Ra tioL IU Shu2liang1 , SH EN J ie2 , L IU De2xin1 , L I Yu2feng1 , ZHU O So ng2f ang2 , Q IU Rui2xing2 , R EN Li2ho ng1 , XIAO Hao2do ng1(1 . State Key L aboratory of Engine Co mbustio n , Tianjin U niversity , Tianjin 300072 , China ;2 . Yuchai Machinery Co mpany L t d. , Yulin 537005 , China)Abstract :The flow performance of t he helical intake port has great influences on direct injection (D I) diesel engine co mbustion and perfor2 mances. Many errors or deviations may occur during t he casting and machining p rocesses of t he cylinder head. In t his paper , a few set s of mechanism were designed for simulating different kinds of port deviation , e. g. port wit h inclination , vertical swelling and eccent ric errors etc. The flow performance of t he port was tested on a steady state flow rig. The result s are as follows. The inclination of t he inlet port in2 fluences greatly t he swirl ratio of t he port . Raising t he ent rance end of t he port will lead to t he reduction of t he port swirl ratio , while re2 ducing t he ent rance end of t he port will lead to a higher port swirl ratio . The swelling of t he inlet port will cause eit her flow coefficient or swirl ratio of t he port to be reduced. As t he eccent ric deviation occurs at t he direction of t he exit of t heport t he swirl ratio will be increaseda little , while t