How do propellers propell a boat.

There are many theories about how a boat propellers propel a boat and how that happens. Who has got it right?

 

You are trolling Tom.
Spoiling for a good argument?

 

This is a discussion forum are you afraid of learning something different?
Do you not have your opinions on how a propeller really propels a boat or jut take for granted what some and accept traditional says? If you are not interested don`t let your imagination run away. What is wrong with sharing experiences.

 

Tom
I was at a well known prop designer builders in the usa the other day
They were telling me about a world record holding prop they just scanned and all 3 blades different. Which i know is normal.
I said i wonder if someone will ever work out how props work, which drew a great laugh from the lunch table.
Cheers
Ps they are like sails....

 

How do propellers propel a boat

I find propellers very interesting and most interesting is how some people think they work even very experienced race boat fans come up with all sorts of explanations.
Try Google propeller blades with vortex generators to reduce blade tip losses.
or high rake angle high speed boat propeller with low energy losses.

 

props?

When we talk racing props, they get better and better when the material has stayed the same over 50 years
Surely that means the science is not exact?
Its all art.

 

props are screwy (sorry, I couldn't help myself)

 

It was a joke - mostly.

We will see if you get any actual "factual" responses.

You can tell me "I told you so" if anything comes up.
But in fact, this is a "discussion forum" so this is my discussion.

 

Water has inertia, the propellor applies a force to it, you get a reaction. Simples !

 

Thats 2 reactions, the suction side and the pressure side?

 

No such thing as suction in our universe, but there is pressure. Or lack of it.

 

too true, just high and low pressures

 

If you tell us which theories you are referring to, perhaps we could discuss them and see which ones are right.

 

In engineering no model/theory agrees with reality exactly, but depending on the use some models/theories are more applicable than others.

 

Or suction can be defined as pressure lower than ambient.