A study on the free falling motion of raindrops with a diameter of 5 mm in still air at 20℃
The article adopts the spherical raindrop model and uses the strict expression of the air resistance coefficient CD,namely the Wallis formula,to calculate the v～t image of a raindrop with a diameter of 5 mm when it freely falls from rest in still air at 20 ℃.The article also solves the analytical and universal v(t)function under the approximation of CD being uniformly taken as 0.44,and produces the corresponding v～t image.The results show that these two v～t curves almost completely coincide,indicating that the approximate treatment is completely appropriate.The article explains the reason for this and points out the reason for the limit rate measured in the ex-periment is 2.00 m/s lower than the theoretical value under the spherical raindrop model is the actual raindrop shape presents a Hamburg shape,and its actual air resistance coefficient is calculated to be about 0.52.We be-lieve that the spherical raindrop model is generally practical.
万方数据
维普
