MEC203 Chapter 8 Definitions Flashcards
Define Velocity boundary layer
The region of flow in which the effects of the viscous shearing forces caused by fluid viscosity are felt
Define Boundary layer region
The viscous effects and the velocity changes are significant
Define Irrotational (core) flow region
The frictional effects are negligible and the velocity remains essentially constant in the radial direction
Define Hydrodynamic entrance region
The region from the pipe inlet to the point at which the velocity profile is fully developed
Define Hydrodynamic entry length
The length of the hydrodynamic entrance region
Define Hydrodynamically fully developed region
The region beyond the entrance region in which the velocity profile is fully developed and remains unchanged
Define Thermal entrance region
The region of flow over which the thermal boundary layer develops and reaches the tube center
Define Thermal entry length
The length of the thermal entrance region
Define Thermally developing flow
Flow in the thermal entrance region. This is the region where the temperature profile develops.
Define Thermally fully developed flow region
The region beyond the thermal entrance region in which the dimensionless temperature profile remains unchanged
Define Fully developed flow
The region in which the flow is both hydrodynamically and thermally developed
Define NTU
Number of transfer units. A measure of the effectiveness of the heat transfer systems
