Limitations of Prandtl's Boundary Layer Equations

• The Approximation of the Boundary layer is applicable for laminar flows with large Reynolds number.
• As the Reynolds number decreases, the accuracy decreases.
• Assumption that $\frac{\partial p}{\partial y}$ is not valid for flow on a curved surface where the curvature is close to the value of $\delta$
• In case of Back-flow, the equations aren’t valid at the region of separation.