# How to use Bernoulli's Equation Correctly?

1. Oct 12, 2006

### xian_kgx

One large pipe is splitted into 2 smaller pipes. Can we use Bernoulli's equation and say that the total head at a point in the large pipe is equal to a point at one of the 2 smaller pipes? Why is energy not conserved?

2. Oct 13, 2006

### FredGarvin

There are 3 main assumptions in the derivation of the Bernoulli equation. What are they?

3. Oct 13, 2006

### machinest

energy not conserved cuase of the losses-
as long as there is a flow then there is a difference in energy-which cuased the flow to occur-
there is the primary losses(friction)and the secondry(valve,bend-)which u don have here--
if u could show ur pipe system-it would be more clear for us-
wish i could help

4. Oct 14, 2006

### RainmanAero

Hi Fred,

Good hints. Check my answers and let me know if I got all of them!
1) Constant mass flow rate (no surges).
2) Frictionless (no heat transfer).
3) Irrotational (translational velocity only).

How'd I do?
Rainman

5. Oct 14, 2006

### FredGarvin

They are:
- Incompressible
- Inviscous