摘要
以三种不同直径的铜管和有机玻璃管构成实验管路系统,研究了横肋管中空气流动阻力特性。在峰高为(0.01～0.11)d,间距为(7～40)d,Re=400～100000范围内,试验提供了从层流到湍流范围内完整的阻力系数曲线。从阻力形成机理,分析了横肋的峰高k,间距s,厚度w等因素对阻力系数的影响。并得到了简明的数据关联式f_r/f_s=1+128(k/d)^(1.36)(s/k)^(-0.41)Re^(0.25) 式中f_r为横肋管阻力系数;f_s为光滑管阻力系数;d为管径。
In this paper flow resistance in three different sizes of traverse-ribbed tubes was measured with air as the working fluid within the range of the following parameters: k/d=0.01～0.11, s/k=7～40, Re=400～100000. Experimental data are shown in terms of curves of Fanning factor versus Reynolds number and correlated by an empirical formulaf_r/f_s=1+128(k/d)^(1.36)(s/k)^(-0.41)Re^(0.25)The influences of roughness geometry such as rib height, spacing and thickness on friction factor are discussed and the total resistance increament in repeated-rib tube is also explained on the basis of the mechanism of resistance.
基金
国家自然科学基金会
关键词
横肋管
流动阻力
传热
flow resistance
transverse ribbed tube
smooth regime
transition regime
completely rough regime
rough Reynolds number: sand roughness
