Drag reduction characteristics of heated spheres falling into water Project supported by the National Natural Science Foundation of China (Grant No. 11672094). |
(color online) Falling velocity of the sphere varying with falling time at Tw = 25 °C and Ts = 25 °C, with black points representing experimental values obtained by the video clips and red line denoting fitted curve from formula V(t) = VT (1e−t/τ). |