Publisher's Synopsis
Excerpt from Using Rheology to Estimate Short-Term Retardant Droplet Sizes
The results presented in this report describe several short term retardants. These materials contain only water and a small amount of a thickening agent which imparts a useful level of viscosity and, usually, elasticity to the mixture. These properties are beneficial in at least three distinct ways. Asthe bulk liquid breaks up into droplets after being released from the aircraft, the average droplet size in the cloud is significantly larger than in the case of pure water. This results in more rapid fall and less wind drift. The larger droplet size and decreased diffusion within each drop result in much less evaporative loss of water. Finally, the thickened mixture adheres to fuel surfaces better than water, retaining the cooling capacity of the material where it is needed. Some short - term retardants also tend to creep over or drain down onto fuel surfaces more readily than do the cur rent long-term products. Retardant products of the long-term type (high salt content) have been empirically developed to maximize performance in the field. This has taken years of operational use. Recently, these materials have been tested in the laboratory, yielding droplet-size values in the 2-mm to 5-mm range for an airspeed of 120 knots. This droplet size range is a logical point of depar ture for systematizing the comparison of the performance of short-term retardants with that of long-term materials. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.