Pipe flow calculation challange

In summary, the problem at hand involves solving for head loss and flow rate in a fluid system using the Darcy-Weisbach equation. It is important to understand the equations involved and to approach the problem in a systematic and logical manner. This may involve using iteration and computer programs to find a solution.
  • #1
samurai_01
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Homework Statement


every where we require at least 3 variables out of 4(l,d,q,hf)l=length,d=diameter,q=flow rate, hf=head loss due to friction. assume water and e=0.02(roughnss coeff)
what shall happen if 2 of them are known and remaining 2 unknown
ex.known=l,d; unknown=hf,q;
we also know the height of tank...H now i am unable to understand how do i solve it.
image of similar prob.@:
http://tinypic.com/r/332qt55/6
NOTE-- we know onlyLength and dia of pipe and properties of fluid and pipe.

Homework Equations


How do we solve and get hf and q at same time.


The Attempt at a Solution


i have tried about 100 methods including iteration by assuming q,hf f etc etc at each try, but i am never able to get any near to correct solution.
I have written programs in C for the purpose. I have posted image of system i need to solve, please help.I have even tried hazen williams equation but i want to get the answer with Darcy equation... please help
 
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  • #2


it is important to approach problems in a systematic and logical manner. In this case, it seems like you have already tried multiple methods but have not been successful in finding a solution. Here are some steps you can take to help solve this problem:

1. Identify the known and unknown variables: In this case, the known variables are length and diameter of the pipe, while the unknown variables are head loss due to friction (hf) and flow rate (q).

2. Understand the equations involved: In fluid mechanics, there are several equations that can be used to solve for head loss and flow rate. These include the Darcy-Weisbach equation, Hazen-Williams equation, and Manning's equation. It is important to understand the assumptions and limitations of each equation before applying it to your problem.

3. Choose an appropriate equation: Based on the information provided, it seems like the Darcy-Weisbach equation would be the most appropriate to use in this case.

4. Set up the equation: The Darcy-Weisbach equation is hf = f (L/D) (V^2/2g), where f is the friction factor, L is the length of the pipe, D is the diameter of the pipe, V is the velocity of the fluid, and g is the acceleration due to gravity. Since you know the values for L and D, you can rearrange the equation to solve for either hf or V.

5. Use the known height of the tank: It is mentioned that the height of the tank is known. This can be used to calculate the velocity of the fluid using the Bernoulli equation, which relates the pressure and velocity at different points in a fluid system.

6. Use iteration: Since the Darcy-Weisbach equation involves the unknown variable f, it will likely require some iteration to find a solution. This means that you will need to make an initial guess for the value of f and then use that value to calculate hf. If the calculated hf does not match the known height of the tank, then you will need to adjust your guess for f and repeat the calculation until you get a solution that is close enough to the known value.

7. Consider using a computer program: Since you have already written a program in C, you may want to consider using it to solve this problem. Make sure that your program is set up correctly and that you are using the correct equations and values for the variables
 

1. What is a pipe flow calculation challenge?

A pipe flow calculation challenge is a problem that requires the use of equations and calculations to determine the flow rate, pressure, or other properties of a fluid flowing through a pipe system.

2. What are the factors that affect pipe flow calculations?

There are several factors that can affect pipe flow calculations, including the properties of the fluid (such as viscosity and density), the diameter and length of the pipe, and the roughness of the pipe's inner surface.

3. How do you determine the flow rate in a pipe system?

The flow rate in a pipe system can be determined by using the continuity equation, which states that the mass flow rate into a closed system must equal the mass flow rate out of the system. This equation can be solved for the flow rate using the known properties of the fluid and the pipe system.

4. What are some common challenges in pipe flow calculations?

Some common challenges in pipe flow calculations include dealing with complex fluid properties, accounting for changes in pipe diameter or direction, and accurately modeling the effects of turbulence and friction in the pipe system.

5. How can pipe flow calculations be used in real-world applications?

Pipe flow calculations are used in a wide range of real-world applications, such as designing plumbing and irrigation systems, calculating the flow rate of oil or gas in pipelines, and determining the pressure drop in a water distribution system. They are also important in industries such as chemical engineering, where precise control of fluid flow is essential for manufacturing processes.

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