# Friction loss in pipe

• foo9008
However, both are acceptable and can be converted to each other using the relationship fD = 4fF. In summary, the major loss in fluid due to pipe friction is calculated using the Darcy-Weisbach equation, which can be written in terms of either the Darcy or Fanning friction factors. The difference between the two is a factor of 4, and both are correct depending on which factor is provided in the problem.

## Homework Statement

the major loss in the fluid due to pipe friction is f(L)(v^2) / 2gD , (darcy weisbech equation)

why the author use 4fL(V^2) / 2gD ? in the equation ? is it wrong ?

## The Attempt at a Solution

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Hi! The Darcy-Weisbach equation is written in terms of the Darcy friction factor (fD), whereas the second equation you posted is probably written in terms of the Fanning friction factor (fF), which is weird, because the problem provides the Darcy factor. The relationship between them is fD = 4fF, so both equations are correct depending on the friction factor you use. However, in your example, they just plugged in the 0.008, so yeah, there is something wrong with the calculation or the problem statement. This is actually a pretty common mistake. Is that from a textbook?

As a generalization, the Darcy friction factor is commonly used in mechanical engineering calculations, while the Fanning factor is used in chemical engineering calculations.

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## 1. What is friction loss in pipe?

Friction loss in pipe refers to the energy that is lost due to the resistance of the fluid flowing through the pipe. This resistance is caused by the friction between the fluid and the inner walls of the pipe, as well as any changes in direction or velocity of the fluid.

## 2. Why is friction loss important?

Friction loss is important because it directly affects the flow rate and pressure of the fluid in the pipe. This can impact the efficiency of a system and can result in higher energy costs. It is also crucial to consider when designing and sizing pipes for a particular application.

## 3. How is friction loss calculated?

Friction loss in pipe is calculated using the Darcy-Weisbach equation, which takes into account factors such as the length and diameter of the pipe, the fluid properties, and the roughness of the pipe wall. There are also various online calculators and software programs available to assist with these calculations.

## 4. What factors can affect friction loss in pipe?

There are several factors that can affect friction loss in pipe, including the flow rate, pipe length and diameter, fluid viscosity and density, and the roughness of the pipe material. Changes in any of these factors can result in changes to the overall friction loss.

## 5. How can friction loss be reduced?

Friction loss can be reduced by using pipes with smoother inner walls, increasing the pipe diameter, or decreasing the flow rate. Additionally, regular maintenance and cleaning of pipes can help to reduce the build-up of debris and roughness on the inner walls, thereby reducing friction loss.