Figure 2
From: Hydrodynamic Kelvin–Helmholtz instability on metallic surface
Four cases of surface temporal evolutions. ( a–d) Maps of surface temporal morphologies of quiescent Cu plate surface (blue) flowed by ideal fluid H2O (grey) with tangential velocity u0, as calculated by finite element methods23. Each Cu plate has fixed density ρ1 = 8.9 kg/m3, fixed shear modulus 39.39 GPa and the same initial perturbation with 250 μm wavelength and 10 μm amplitude. The four cases are obtained by varying tangential velocity, fluid densities and yield strength of Cu for case a u0 = 1.0 mm/μs, ρ2 = 2.0 kg/m3, Y = 500 MPa, case (b) u0 = 1.0 mm/μs, ρ2 = 3.0 kg/m3, Y = 500 MPa, case (c) u0 = 2.0 mm/μs, ρ2 = 1.0 kg/m3, Y = 500 MPa and case (d) u0 = 2.0 mm/μs, ρ2 = 1.0 kg/m3, Y = 100 MPa. Surface morphologies of four cases at time 0.05 μs, 0.1 μs, 0.15 μs, 0.2 μs are given respectively. The red arrow in each surface at time 0.2 μs is the schematic of surface motion direction. (e) The growth factor z of each case is extracted from simulation.
