International Journal of Heat and Mass Transfer, Vol.89, 913-919, 2015
Water temperature influence on the spherical body's falling velocity
An article represents the results of the experimental investigation of the falling velocity dependence on the spherical body's metal type, size and Leidenfrost effect for the different temperatures of the body and water. It was stated that the growth of the body's temperature increased the falling velocity due to the change of the water parameters (density, phase, etc.) nearby the surface of the body. Maximal augmentation of the velocity (37-38%) was noticed for the sphere which temperature was equal to 650 degrees C and water temperature was close to the saturation temperature (99 degrees C). Falling velocity of the sphere made from the steel was almost the same like of that made from the copper; falling velocity of the aluminum sphere was much less due to the less mass of it. Bigger bodies had greater velocity because of the bigger mass and relatively less resistance. Augmentation of the falling velocity did not correspond directly on the body's temperature growth. There existed an appropriate interval of the body's surface temperature for which the falling velocity was the highest. Difference between the falling velocity of the hot and cold bodies increased gradually with the rise of the falling time and reached 25% for the stainless steel sphere which temperature was 410 degrees C and water temperature was 14 degrees C. (C) 2015 Elsevier Ltd. All rights reserved.