False

Laminar and Hydrodynamic Boundary Layers

Boundary layer refers to the thin layer of fluid that develops near the surface of an object when fluid flows over it. This layer is important because it affects the overall flow pattern and heat transfer between the fluid and the surface. The boundary layer can be divided into two types: laminar and turbulent.

- Laminar boundary layer: This type of boundary layer is characterized by smooth, orderly flow of fluid particles parallel to the surface. The thickness of the laminar boundary layer increases with distance from the leading edge of the surface.
- Turbulent boundary layer: In this type of boundary layer, the flow becomes irregular and chaotic, with fluid particles moving in all directions. The thickness of the turbulent boundary layer is greater than that of the laminar boundary layer.

Thermal and Hydrodynamic Boundary Layers

The thermal boundary layer refers to the region of fluid near the surface where the temperature changes due to heat transfer between the surface and the fluid. The hydrodynamic boundary layer refers to the region where the velocity of the fluid changes due to friction between the surface and the fluid.

Relationship between Thermal and Hydrodynamic Boundary Layers

The thermal and hydrodynamic boundary layers are related because they affect each other. The thickness of the thermal boundary layer is influenced by the thickness of the hydrodynamic boundary layer, and vice versa.

False Statement

For air near atmosphere conditions flowing over a flat plate, the laminar thermal boundary layer is thicker than the hydrodynamic boundary layer. This statement is false because the thickness of the thermal boundary layer is typically less than that of the hydrodynamic boundary layer. This is because heat transfer is a slower process than fluid motion, so the thermal boundary layer develops more slowly than the hydrodynamic boundary layer.