# Fluid speed in pipe

1. Dec 3, 2011

### milan.007

Just a general question, if there is an obstacle in a pipe, such as a turbine, will the speed of the fluid before the turbine be the same as after it? Or will the turbine cause the speed in the whole pipe to slow down?

2. Dec 3, 2011

### iceworm

If the turbine isn't leaking - the mass of the fluid entering the turbine equals the mass of the fluid leaving. So if the inlet and outlet are the same size and the fluid is not compressible, the the velocity in and out are the same. There will be a pressure drop across the turbine - has to be or it can not extract any energy.

As for your second question: It could. The turbine will have a pressure drop across it. Depending on the fluid source, the additional pressure drop could easily slow down the velocity.

Two disclaimers:
1. I've told you more than I know.

2. This is hydraulics as explained per an electrical background

ice

3. Dec 3, 2011

### milan.007

Thanks alot, that answers my question.