Understanding the Need to Change π3 to π3' in Buckingham Theorem

  • Thread starter welovephysics
  • Start date
  • Tags
    Theorem
In summary, the question being discussed is whether there is a need to change the value of π3 to its inverse, π3-1, when using it as a variable in a function π1. The argument is that since π1 is also a function of π2 and π3, it should also be a function of π2 and π3-1. However, the benefit of making this change is not clear.
  • #1
welovephysics
39
0

Homework Statement


why there is a need to change π3 to π3 ' (which is inverse of reynold number)? (in 2nd picture)

Homework Equations

The Attempt at a Solution


why can we do so ? i was told that π1 = f( π2 , π3 , ...)
if we use π3' , which is this will change the original meaning of π1 = f( π2 , π3 , ...) , am i right ? IMO, this is wrong , there's no need to change π1 = f( π2 , π3 , ...) 3 to π1 = f( π2 , π3 , ...) 3 ' ...
can someone explain on it ?
[/B]
 

Attachments

  • 197.PNG
    197.PNG
    25.4 KB · Views: 392
  • 198.PNG
    198.PNG
    51.1 KB · Views: 407
Physics news on Phys.org
  • #2
If π1 is a function of π2 and π3 then it is also true that it is a function of π2 and π3-1. It's just a different function.
Until you have locked in how f is defined, you are free to choose how to define it.
That said, I don't see the advantage here in switching from π3 to π3-1.
 

Related to Understanding the Need to Change π3 to π3' in Buckingham Theorem

What is Buckingham Theorem?

Buckingham Theorem, also known as the π theorem, is a mathematical principle that states that a physical problem involving a certain number of variables can be reduced to a dimensionless form by using a set of dimensionless parameters. It is commonly used in engineering and physics to simplify complex equations and models.

Why is it necessary to change π3 to π3' in Buckingham Theorem?

The need to change π3 to π3' arises when the original set of dimensionless parameters, π1, π2, and π3, are not independent of each other. This means that one of the parameters can be expressed as a combination of the other two. To ensure that the set of parameters is truly independent, π3 is replaced with a new parameter, π3', which eliminates any redundancies.

How does changing π3 to π3' affect the validity of Buckingham Theorem?

Changing π3 to π3' does not affect the validity of Buckingham Theorem. It simply ensures that the set of dimensionless parameters used in the theorem is truly independent, which is necessary for the theorem to be applied accurately.

What are the implications of not changing π3 to π3' in Buckingham Theorem?

If π3 is not changed to π3', it can result in incorrect solutions and interpretations of the physical problem being studied. The use of dependent parameters can introduce errors and lead to unreliable predictions. Therefore, it is important to follow the principles of Buckingham Theorem and make the necessary changes to ensure the validity of the results.

Can Buckingham Theorem be applied to all physical problems?

Buckingham Theorem can be applied to most physical problems, as long as the problem can be described using a set of variables with consistent units. However, there may be some cases where the theorem cannot be applied, such as in problems involving quantum mechanics or electromagnetic phenomena.

Similar threads

  • Introductory Physics Homework Help
Replies
11
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Advanced Physics Homework Help
Replies
13
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
769
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
5K
  • Introductory Physics Homework Help
Replies
1
Views
163
  • Introductory Physics Homework Help
Replies
3
Views
222
  • Introductory Physics Homework Help
Replies
8
Views
938
Back
Top