... 15 14 .8 11 .94.3 1 2.64 1. 380. 71 52 14 .66.546.035 .1 3 19 79 -19 80 10 .8 18 .27.463.32 1. 760.980.4640.24 1. 12 1. 91 1.98 21. 1 1980 -19 81 23.334.2 10 .63.572.46 1. 56 1. 85.375.664. 21 2.292.93 19 81- 198236.632.6 11 .84 .1 72.33 1. 592.352.553.092.32 .1 6 11 .7 19 82 -19 834.976.8 1 5.935.573.5 1 2.064.7 1. 446.0 1 3.073 .1 83.55 19 83 -19 8432.622.36 .1 63.42.76 1. 64 1. 534.2 1 5.922.993.622.42 19 84 -19 8525.323 11 .24.683.572.532.925.228.6 1 2.66 1. 844.06 19 85 -19 86 15 .2 17 .7 18 5.672.842.2 1 1. 31 6.282.7 1 1.722.27 1. 74 19 86 -19 8730.4 13 .7 11 .52.95 1. 49 1. 22 1. 2 1. 162 .1 40.9096.6 1 10.8 19 87 -19 883.03 14 .39.082.95 1. 7 1. 4 1 1.23 1. 622.232.44 1. 922.65 19 88 -19 89 ... 00,5980,5980,5980 ,12 00,0060,004 11 ,13 1 4,2944,294 911 ,000635 ,13 4 2,250273, 61 6 10 ,10 7 7,277 19 803.32 1. 760.980.460.24 1. 12 1. 91 1.98 21. 1 23.334.2 10 .68. 41 19 81 3.572.46 1. 56 1. 8 ... nhám(TCVN 915 1:2 012 )0,250,253 1, 46 10 0 1, 46 0,5 10 10 00 ,1 0 ,1 0, 011 5Re 1, 15 2 214 330dλ− ×∆ × × = × + = × + = ÷ ÷ 24 10 ,76 1, 930, 011 5 0.02( ) 1, 15 2 9, 81 dh m= × ×...