# How important is Fluid Mechanics and Hydraulics to Civil Engineers?

1. May 20, 2012

### jnlbctln

I know the main focus of Civil Engineers are the strength of the structures. I also know that Fluid Mechanics and Hydraulics are important in designing dams or other structures related to fluid. But what about to Building structures? How is it important?

2. May 21, 2012

### rsq_a

I can't say as an engineer, but simply as an applied mathematician: it's all mechanics, isn't it? Fluid mechanics and solid mechanics are intimately related in the sense that a lot of techniques and theories have analogues in one and the other. So at least from a theoretical standpoint, many fluid mechanicians have been able to start working in solid mechanics and vice versa.

3. May 21, 2012

### JakeBrodskyPE

When designing infrastructure such as water distribution systems, pumping stations, dams, and treatment plants, Civil Engineers need to understand both fluid statics and dynamics. When I was in school 25 years ago, this was not routinely taught to them and the results were as plain as day for me to see.

For example, water is pumped at a certain rate to a junction box. You have a sluice gate at that junction box. Is the head of the water flowing through that sluice gate low enough so as to stay below an overflow weir? How large should that sluice gate be?

These are mistakes that Registered Professional Engineers made. Real mistakes. Significant mistakes that make the operation of this facility much more difficult than it needed to be.

So, yes, civil engineers should study statics at a bare minimum, and dynamics as well. Look in to Froude numbers and fluid shock waves to estimate water behavior at the base of a dam. Look in to hydraulic jump equations and study flow meters in flumes, venturi sections, read about the manning flow equation --there are lots of very practical, hands on things you need to know about this subject.

Do me a favor and pay extra close attention to this area. Perhaps you can be the wave of students who teach the old timers a thing or two. I'm sick and tired of seeing stupid excuses from engineers who should know better than to bolt a venturi metering section directly to a pipe elbow.