Cleaning of thick viscoplastic soil layers by impinging water jets

The removal of thick (approximately 1–10 mm) layers three viscoplastic soft-solid food-related materials (a moisturising cream, Biscoff spread and smooth peanut butter) from polymethylmethacrylate plates by turbulent, coherent, 2 mm diameter water jets was studied for jet velocities 10.6–25.4 m s −1 (10 500 < Re 25 400). When the layer thickness smaller than nozzle diameter, soil involved growth a circular crater. With thicker layers, removed initially formed blister which subsequently ruptured, cratering followed. Blister formation dynamics were cream using 3 nozzles, indicated that this process could be described simple geometric models. Tests with on glass stainless steel substrates little effect substrate behaviour. rate in regime quantified kinetic model Glover et al. (2016) parameters compared trend predicted Fernandes Wilson (2020): qualitative agreement evident. results used to revisit study impinging Carbopol® reported Tuck (2019, 2020) extract their data. • Cleaning investigated dual camera arrangement. Removal mode depends ratio film thickness/nozzle diameter. involves formation, rupture cratering. Cratering exhibits momentum-driven removal, similar thin layers. Results literature analysed: these follow expected trends.