出口风速 meaning in Chinese
outlet air velocity
Examples
- Through tests of different nozzle - equipped emergency ventilation systems , the authors hold that , under the same condition of air volume and air pressure , the round mouth nozzle and its parameters is the best , thus provides reference for the design of emergency ventilation system
对不同类型喷口的通风系统性能进行了试验,提出在相同的风量和风压下,椭圆喷口的通风功能和防灾能力最强,喷口出口风速提高有利于提高其风量效率等结论,为隧道事故通风系统提供了设计依据。 - For shutters , the results show : 1 ) according to the formula p = , the theoretical value of is calculated by the effective velocity of the flow , and its engineering value is calculated by the arriving velocity of the flow , the relationship between the theoretical value of and its engineering value is 2 ) the smaller value of declining angle will result in the smaller pressure loss and smaller outlet velocities . as a result , the declining angle of 30 掳 or less is recommended in some places which need small wind velocity , such as broadcasting studio and library , and the declining angle of 45 掳 or less is recommended in places which need big wind velocity , such as cinema and office ; 3 ) the larger value of ratio between the wide of the shutter b and the space between two boards h ( b / h ) will result in the larger pressure loss and smaller outlet velocities . the range of b / h from 0 . 8 to 2 . 0 and the optimum value 1 . 2 is recommended ; 4 ) the range of b from 10 mm to 50 nun and the optimum value 40 mm is recommended ; 5 ) the proper thickness of the boards 8 of the shutters is 1 . 5 mm ; 6 ) cuneiform boards should replace the rectangle inlet boards of the shutters in order to obtain better ventilation
数值模拟采用fluent软件,计算结果用excel进行处理,通过对大量数值工况进行数值模拟计算,结果表明:对于单侧百叶风口,计算表明: 1 )对于公式p = ( ~ 2 ) 2 ,的理论计算值中定义为流体流经百叶风口内部时的速度,即有效速度,而工程上常使用流体的来流速度来计算,计算表明,的理论计算值与工程应用值的关系为( _ (理论) ) ( _ (工程) ) = 0 . 813 ; 2 )当来流速度一定时,挡板倾斜角度越小,压力损失越小、出口速度越小;因此在要求进口风速比较小的场所,如播音室、图书馆等,宜采用挡板角度30的百叶风口;在要求进口风速比较大的场所,如电影院、办公室等,百叶挡板的角度应选45 ; 3 )当来流速度一定时,百叶挡板的挡板宽度b与挡板间距h的比值b h越大,压力损失越大,出口速度越小,计算表明,鉴于压力损失、出口风速、板间形成涡流区的大小,百叶挡板的b h值取0 . 8到2 . 0之间, b h = 1 . 2为最佳值; 4 )当来流速度一定时,在计算的条件下,当百叶挡板宽度b = 40mm时,百叶挡板的阻力系数最小,考虑到涡流区等的影响,建议选用10mm b 50mm的百叶挡板;西安建筑科技大学硕士学位论文5 )百叶挡板的厚度取为1 . sinln为好; 6 )百叶挡板的入口侧可选用具有倾斜度的楔形挡板来代替矩形挡板,利用其较好的导流作用,可得到更好的出流效果。