The College of Science in the Department of Mathematics discussed a seminar entitled on Instability of Incompressible Fluid Flow in Porous Medium and Fluid Layers for postgraduate student Shehzalan Shaker Hajwal. This seminar focused on three main principles: first, the first section examines four challenges concerning Poiseuille flow instability in bidisperse porous media. The subsequent part then focuses on Poiseuille flow problems within monodisperse porous media, investigating two models in this context. The third part is concerned with the study of the instability of Poiseuille flow in a fluid layer. The study carefully examines how different parameters influence the instability of the systems.