Modeling and simulation of capillary ridges on the free surface dynamics of third-grade fluid

Abstract

Abstract Most of the viscoelastic fluids have deformation while flowing over a heated plate. A typical feature of a thin viscous or viscoelastic fluid is the formation of the capillary ridges over locally heated plates. The creation of such ridges in the thin-film surface can affect the smoothness of the coating. This work particularly concerned the flow of non-Newtonian third-grade fluid over an inclined heated plate and the formation of ridges. The conservation laws associated with free surface and wall boundary conditions model the two-dimensional fluid flow. The long wave approximation of the model results in an equation of evolution to explain the structure of free surfaces. The resulting equation is discretized implicitly using the finite volume method. The obtained results are discussed for different flow parameters that affect capillary ridge emergence on the free surface. Variation in the height of capillary ridges of third-grade fluid is compared with the second-grade fluid and Newtonian fluid flow. We observe, the ridge size gets smaller for the third-grade fluid compared to the Newtonian and the second-grade fluid. Our analysis investigates how the third-grade viscoelastic parameters affect the dynamics of the free surface and the size of the capillary ridge concerning temperature changes and other phenomena of interest.