其中4= 20/3600 0.708m/s 元 ×(0.01) 0.1 u =u =0.708× =2.83m/s 0.05 常温下的水,p=1000kg/m,=1×10Pa·S 1 pd,1000×0.708×0.1 Re 7.08×104>4000 l×10 故流型属湍流。 Re pu,d 1000×2.83×0.05 =1.42×103>4000 1×10 故流型属湍流。7.08 10 4000 1 10 1000 0.708 0.1 Re 4 3 1 1 1 = = = − u d 1.42 10 4000 1 10 1000 2.83 0.05 Re 5 3 2 2 2 = = = − u d 故流型属湍流。 故流型属湍流。 m s A q u V 0.708 / (0.01) 4 20/ 3600 2 1 1 1 = = = m s d d u u 2.83 / 0.05 0.1 0.708 2 2 2 1 2 1 = = = 其中 6 常温下的水, , 3 = 1000kg / m = Pa s −3 1 10