Linear Stability of Sharp and Diffuse Interfaces Under Shear Available to Purchase

We show that diffuse interfaces in shear flow are prone to instabilities that are of the same origin and character as the Yih-instability (for sharp interfaces between immiscible fluids). We also show that the development of these “Yih-like” instabilities towards “Yih” is monotonic, and that the agreement with Yih becomes quantitative as the limits of zero thickness and no-diffusion are approached.