Alejandro Villanueva
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, 6.1 Convection Boundary Layers
Concept: When fluid flows over a surface, two thin regions form:
• Velocity boundary layer: region where fluid velocity increases from 0 (no-slip) to free
stream velocity V∞
• Thermal boundary layer: region where temperature transitions from wall temperature Ts
to free stream temperature T∞
Assumptions:
• Steady-state
• Incompressible flow
• No internal generation
Intuition: Surface influences flow and temperature only in its vicinity — beyond that, the fluid is
unaffected.
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