#### Entrance Length in Pipe Flow: Summary

The answers to the ConcepTests are given below and will open in a separate window.

##### Key points from this module:

- An entrance length in pipes is where viscous forces create a boundary layer.
- The equation for entrance length for laminar flow differs from that for turbulent flow.
- The velocity doesn’t change with respect to the length of the pipe in fully-developed flow.

##### From studying this module, you should now be able to:

- Determine if flow in a pipe is laminar or turbulent.
- Calculate the entrance length for both laminar and turbulent flow.
- Determine where a flow becomes fully-developed.

*Prepared by Janet deGrazia, Department of Chemical and Biological Engineering, University of Colorado Boulder*