Learning how to calculate the pressure drop in a pipe with major and minor losses can be very challenging at first for many students, especially those who have never been exposed to a fluids class. As the length of your video proves, learning the Bernoulli equation and the losses due to friction is a lengthy process and can be confusing to fluid mechanic students. Your video is very concise, but also gives great detailed step-by-step instructions. The use of colored highlighters to point and illustrate how to read the Moody Chart or explain a step is also very helpful.
My guess is that you would have to find a function for density at each position along the pipe, then integrate across the length of the pipe to find the average density and use that in these equations.
Great question. In this case, the term we are calculating is a friction loss term. That occurs throughout the pipe, so we want to use the velocity that is in the pipe, which is v1. The only difference between v1 and v2 is the diameter. v2 was calculated with the diameter of the faucet, so that wouldn't be what we want to use here or in the minor losses term. I hope that helps!
Thanks for your valuable input, I appreciate that very much! I am an electric engineer, so these pressure calculations are not something I know too well, but I find this very fascinating area to get some basic understanding and your presentation was very educating, despite of the imperial units, which I am not familiar with (we in Europe use SI units) :-) What about if the ducting was such that the first 30 ft was as it is now (1 "), but the last 15 feet would be implemented with a bigger pipes, let's say 2". Now the velocity would not be the same through the whole ducting. Should I now do the math in two parts, so that I would first calculate the pressure loss for the first 30 feet (let's call it PL1) with the formula you presented, and then the pressure loss for the latter 15 feet part (PL2), again with the same formula. Then sum these two values PL1 and PL2 together?
The Reynold's number calculated in the video still has units. It should be dimensionless. I believe the correct value for the Reynold's number is around 9.07e5. This changes the friction factor to around 0.0129, but changes the final answer only a little, to about -10.21 psi. Does anyone else get this?
In this calculations v2 find out, flowrate will be same but area how to change it because i have 120m pipe then how to start to endpoint there is no changes in diameter of the pipe> now for this condition what is the v2 value?????? thanks for my all quarry reply.
What if you had an intermediate outlet, do you have a video of what is involved in a problem of that nature? If you don´t, could you recommend a bibliography? Thanks in advance.
one of the primary losses term should have something close to V2 isn't it? summing in all the sections on the pipe having "V1" as the average velocity is acceptable but the end or last section has different diameter so in my humble opinion it shoul have different V, but still no body cares using friction factors and "KL" terms is already an approximation
Learning how to calculate the pressure drop in a pipe with major and minor losses can be very challenging at first for many students, especially those who have never been exposed to a fluids class. As the length of your video proves, learning the Bernoulli equation and the losses due to friction is a lengthy process and can be confusing to fluid mechanic students. Your video is very concise, but also gives great detailed step-by-step instructions. The use of colored highlighters to point and illustrate how to read the Moody Chart or explain a step is also very helpful.
The Imperial System was problematic but acted like an interesting challenge for me , I love the stuff you've posted Good work man!!!!!!
Oh god these units. It hurts..
English units... pain... same thing
Thank you very much for the video. How can we calculate the pressure drop if we have a gas with significant density changes along the pipe?
My guess is that you would have to find a function for density at each position along the pipe, then integrate across the length of the pipe to find the average density and use that in these equations.
Why did you take velocity as V1 at 7:41?
All was clear, except why did you use the v1 (4.08) value for the V (video 8:04 and onwards)? Could you open this part a bit, thanks!
Great question. In this case, the term we are calculating is a friction loss term. That occurs throughout the pipe, so we want to use the velocity that is in the pipe, which is v1. The only difference between v1 and v2 is the diameter. v2 was calculated with the diameter of the faucet, so that wouldn't be what we want to use here or in the minor losses term. I hope that helps!
Thanks for your valuable input, I appreciate that very much! I am an electric engineer, so these pressure calculations are not something I know too well, but I find this very fascinating area to get some basic understanding and your presentation was very educating, despite of the imperial units, which I am not familiar with (we in Europe use SI units) :-)
What about if the ducting was such that the first 30 ft was as it is now (1 "), but the last 15 feet would be implemented with a bigger pipes, let's say 2". Now the velocity would not be the same through the whole ducting. Should I now do the math in two parts, so that I would first calculate the pressure loss for the first 30 feet (let's call it PL1) with the formula you presented, and then the pressure loss for the latter 15 feet part (PL2), again with the same formula. Then sum these two values PL1 and PL2 together?
tanks to help me but what about the closed loop pipe line flows in the pipes and pressure heads at the nodes ?
The Reynold's number calculated in the video still has units. It should be dimensionless. I believe the correct value for the Reynold's number is around 9.07e5. This changes the friction factor to around 0.0129, but changes the final answer only a little, to about -10.21 psi. Does anyone else get this?
The Reynold's number is indeed dimensionless in this video, as shown at 2:39. I'm not sure how you got the different answer. Can you elaborate?
Great video sir, Thank You. Btw would you happy to share the reference of fitting coefficient's table?
How did you write that "GOAL" ever so perfectly?
In this calculations v2 find out, flowrate will be same but area how to change it because i have 120m pipe then how to start to endpoint there is no changes in diameter of the pipe> now for this condition what is the v2 value?????? thanks for my all quarry reply.
Would diameter differences count for the friction factor or the K values?
What table are you using to determine form loss coefficients?
Please any on explain end closed pressure pipe some time later the pressure is reducing or not.
Thank you very much you are great god bless you
Shouldn't the velocity used in in OUTLET for minor loss be V2?
It's the resulting loss due to the entire length of the pipe. This is why average velocity is used over V2.
Only the outlet of pipe is change not the entire length
What if you had an intermediate outlet, do you have a video of what is involved in a problem of that nature? If you don´t, could you recommend a bibliography? Thanks in advance.
one of the primary losses term should have something close to V2 isn't it? summing in all the sections on the pipe having "V1" as the average velocity is acceptable but the end or last section has different diameter so in my humble opinion it shoul have different V, but still no body cares using friction factors and "KL" terms is already an approximation
a pump connected to the pipe and pump discharge pressure is 2.3 bar then what is pressure drop in pipeline
I agree very nice a big help!
Very nice. Thanks
Would the equation will be the very same if the substance were air, not water?
Great Video... also,
1) what if the circuit had variable diameter pipes
2) What if the circuit had variable sections..
The audio is LOW :(
what is KL how to calculate this minor losses how to find out KL?????????
กิตติพล ขาวงาม
What the fuck is a slug/ft^3 😂😂😂