Accession Number : ADP001012

Title :   Aerodynamic Breakup of Viscoelastic Solutions,

Corporate Author : ARMY ARMAMENT RESEARCH AND DEVELOPMENT COMMAND ABERDEEN PROVING GROUND MD CHEMICAL SYSTEMS LAB

Personal Author(s) : Matta,Joseph E.

Report Date : FEB 1983

Pagination or Media Count : 18

Abstract : A helium activated firing device was used to propel viscoelastic fluid slugs (350cc) to Mach 1 velocities. Aerodynamic forces disrupt the slug which eventually transforms into a cloud of droplets that fall on the ground below. Various concentrations and types of polymethyl methacrylate in diethylmalonate were disseminated. The resultant average drop sizes for each trial were measured and shown to significantly increase with the addition of polymers. A correlation between average drop size and fluid viscosity was not observed. Both a relative relaxation time deduced from a simple die swell experiment and the first normal stress difference N sub 1 correlated dissemination trials conducted at ambient temperatures. However, only the relative relaxation time correlation was consistent with breakup trials using heated fluids. Use of N sub 1 for predicting particle size from dissemination tests employing heated viscoelastic fluids can produce considerable error. (Author)

Descriptors :   *Viscoelasticity, *Aerodynamic forces, *Fluid mechanics, Firing mechanisms(Ammunition), Mach number, Particle size, Tables(Data), Charts, Polymers, Helium, Liquids

Distribution Statement : APPROVED FOR PUBLIC RELEASE