Subject: Fluid Mechanics 2

Topic: Boundary layer theory

Difficulty: Medium

Consider a control volume $A B D C$ in a boundary layer region. $\because$ Rate of mass flow through $A B\left(\dot{m}_{A B}\right.$ (entry)) $=\int_{0}^{\delta} \rho u d y$ (for unit width) $$ \dot{m}_{C D}\left(\text { exit) }=\dot{m}_{A B}+\frac{\partial \dot{m}_{A B}}{\partial x} d x\right. $$ since, mass is conserve, then $$ …