Time evolution of the Kelvin-Helmholtz instability with density contrast of 2. The figure shows the maximum amplitude of the y-component of the velocity without RSST (ξ = 1) in 4096 × 4096 grids (black solid), without RSST (ξ = 1) in the default 1024 × 1024 grids (black dashed), with PVS form (ξ = 10, red), with PVS form (C_max = 3, blue), with PMS form (ξ = 10, green), and with PMS form (C_max = 3, yellow).