【单选题】4 / 10圆管层流的阻力系数为Aλ=64/Re\lambda=64/Reλ=64/Re正确Bλ=0.3164/Re1/4\lambda=0.3164/Re^{1/4}λ=0.3164/Re1/4Cλ=1/Re\lambda=1/Reλ=1/ReDλ=64 Re\lambda=64\,Reλ=64Re参考答案A参考解析λ=64/Re\lambda=64/Reλ=64/Re(K9−15K9-15K9−15)。