The collision efficiency of small drops

✍ Scribed by L. M. Hocking

• Publisher: John Wiley and Sons
• Year: 1959
• Tongue: English
• Weight: 520 KB
• Volume: 85
• Category: Article
• ISSN: 0035-9009
• DOI: 10.1002/qj.49708536305

✦ Synopsis

Abstract

The forces on two moving spheres are found from the Stokes equations of motion, full allowance being made for the mutual interference of the flows round the spheres, and the relative trajectories when they are falling under gravity are calculated so that the collision efficiency E can be found. The values of E are determined for drops of radius up to 30 μ colliding with droplets of any smaller size. The results differ widely from those found by Pearcey and Hill (1957) and it is suggested that the reason for the discrepancy is that the motion of the spheres when they are close together is of great importance in determining E. The results also differ from those found by Schotland and Kaplin (1956). Their experiments did not model the ratio of the density of the spheres to that of the medium through which they are falling and since it is shown that this factor is of importance, their results are not considered applicable to water drops falling in air.