A method for generating linear density profiles in laboratory tanks

Abstract

A by-product of an investigation of turbulent wakes in density stratified liquids [Stockhausen et al., 1966] conducted at the MIT Hydrodynamics Laboratory has been the development of a fast and efficient method for generating a linear density profile in a liquid contained in a large laboratory tank. The method that has been generally used heretofore [e.g., Schooley and Stewart, 1963; Wu,, 1965] consists of carefully placing in the tank a series of fluid layers, with an incremental density difference between successive layers, and then allowing molecular diffusion to smooth the profile. This procedure is very time consuming and tedious and is not practical for use in a large tank, of the dimensions (15.24 meters long, 1.37 meters wide, and 1.07 meters deep) used in the present investigation. Oster [1965] has described a profile generating technique that involves mixing together two fluids of different density while introducing them at different and varying rates into the experimental vessel.