Jet Erosion of Particle Beds: Projecting Critical Suspension Velocities From Effective Clearing / Cleaning Radii

Here we explore the relationship between effective cleaning/clearing radii, ECR, and critical suspension velocities, U_cs. Although one set of physics controls both the radial extent of erosion (i.e., the ECR) and the velocity needed to erode from the center of jet impingement to any given location (i.e., U_cs, typically defined from nozzle center to the vessel center), the relationship between these two remains unexplored quantitatively for nominally non-cohesive solids. Here we advance the model of Kuhn, et al., (PNNL-22816, 2013) as described by Pease, et al. (FEDSM2017-69444, 2017) to evaluate the relationship between the effective clearing/cleaning radius and the nozzle velocity on flat surfaces including flat bottomed vessels. Two governing dimensionless groups are identified. We present both a closed form analytical but transcendental solution and a non-iterative approximation modeled after the Serghides approximation of Colebrook’s nonlinear equation for both ECR versus nozzle velocity and U_cs. Comparison of the model to data from flume testing on a flat surface finds reasonable agreement.