“…From mechanical and engineering points of view, the great amount of research in Bingham fluid has been done in the following areas: non-Newtonian fluid in porous media [68,67,11,47], heat transfer [65,66], mudflows resulting from submarine slides [52,42,43], chemical processing [15,54,25,62], electrorheological (ER) fluids [51,48] and other mechanical properties [43,64,24,41,49,17]. From mathematical point of view, Duvaut, Lions, Brézis and Glowinski have laid a mathematical foundation of Bingham fluid in the framework of variational inequalities [4,5,16,32,29].…”