Many-body dissipative particle dynamics (MDPD) simulation of a pseudoplastic yield-stress fluid with surface tension in some flow processes

The dynamics of Newtonian and pseudoplastic yield-stress fluid drops impacting on solid surfaces are studied numerically by the many body dissipative particle dynamics (MDPD) method. The pseudoplastic yield stress fluid is modelled by two groups of different MDPD particles, in which the parameters are tuned so that the overall fluid behaves in a similar manner to the Herschel-Bulkley pseudoplastic material in simple shear flow. The droplet characteristics are measured by its central drop diameter and its height, and an effective unyielded region is observed in the drop impacting process. The MDPD simulation results compare well with previous drop impact experiments and simplified theoretical studies on the slump test, serving to demonstrate the capability of the MDPD method to explore yield-stress fluid drop's flow processes.