470400 Quantifying the Root Causes of Segregation in Multi-Mechanism Segregation Systems
This paper examines the relationship between segregation velocities when there are multiple causes of segregation. The main question to answer is: what percent of the overall segregation dispersion coefficients are due to the individual mechanisms of segregation? In dispersion, the local convective velocities distribute in a symmetric pattern around the overall average convective velocity. When segregation flux terms are added to the dispersion equations they cause a skewed concentration distribution off of those caused by average convective velocities for each component in the system. We assume that the segregation flux velocities are additive. Thus, to develop a theory that incorporates multi-mechanisms, the relationship between segregation velocity terms for each type of segregation must be understood. The overall segregation profile is a sum of a series of skewed concentration distributions from the average dispersion velocities. These distributions can be combined using the concept of multi-modal distribution functions to yield equivalent overall segregation variance numbers for each component in the mixture. The overall segregation variance numbers can be measured from segregation potential tests done with spectral reflectance techniques (SPECTester). The overall segregation variance data can then be used with convective dispersion models to quantify the segregation of each component by mechanism, providing a detailed look at the cause of segregation in multi-component and multi-mechanism situations. The resulting technique allows a component-by-component characterization showing how much segregation is caused by a prescribed set of individual mechanisms in a mixture consisting of more than two components.