Smooth steel (SG =7.86) sphere is immersed in a stream of ethanol at 20°C moving at 1.5 m/s. Estimate its drag inN from Fig. 5.3a. What stream velocity would quadruple itsdrag? Take D =2.5 cm.

 

5 4 Cylinder length effect Transition to turbulent boundary layer (104 < Re < 10) 3 Cp Cp 1.20 00 40 0.98 0.91 2- 20 10 0.82 0.74 Cylinder (two-dimensional) 3 0.72 0.68 1- 0.64 Sphere 10 102 103 104 105 106 107 pUd Rej = (a)