The friction coefficient is relative to two surfaces in contact. Do you know what are the two materials in contact?

Also friction relates only to a pair of materials and is a function of friction conditions rather than that of materials. It can not be applied to an article such as tube. So you have to specify materials and friction condition such as load and sliding speed, lubrication conditions etc. Then you have to prepare samples having clean contact surfaces with no corrugation and test them under the conditions shown above. In case you want using the corrugated surfaces that will not give you friction coefficient because of intense vibrations.

Respected Masoud Allahkarami Sir....!

I am talking about cooling water tubes......i.e. water is flowing inside the metal tube.....

consider tube is made from copper.

The method to measure the coef. depends on the length of the tube; if it is long enough, you may use the Moody diag.in many available fluid mechanics text. if it is pretty short, the case I think you have, try direct measurement using various fluids. In any case if the length is not considerable, you may ignore it.

Hi Sergey, I´ve not understood what exactly do you pretend to measure with the corrugated tube? Coefficient of friction against which surface?

Hi, Roman, I have been confused since I thought the topic starter was asking about measuring coefficient of friction between two metallic surfaces. But it turned out he was asking about flowing fluid.

I´m still confused about the real meaning of friction coefficient in this question

Just adding my part check the equation, just as one of the followers advised abt moody chart, you have all data you need according to me you designing a pipe is that right? what about flow rate

By measuring the pressure drop along the pipe, you would be able to find the friction head loss by applying Bernoulli equation. Knowing the mass flow rate, pipe lenght and diameter should enable you to find Reynold's nymber and the corresponding friction coefficient.

By repeating the experiment for different mass flow rates and locating (f vs. Re) values to Moody chart, you would be able to find "epsilon/d" for your pipe ... then you can use Moody for any other velocity.