Text this: An immersed interface method for the incompressible Navier-stokes equations with discontinuous viscosity across the interface

 ______      ___      _____      ___      _  __  
|      \\   / _ \\   / ____||   / _ \\   | |/ // 
|  --  //  / //\ \\ / //---`'  | / \ ||  | ' //  
|  --  \\ |  ___  ||\ \\___    | \_/ ||  | . \\  
|______// |_||  |_|| \_____||   \___//   |_|\_\\ 
`------`  `-`   `-`   `----`    `---`    `-` --`