Total pressure drop & static pressure drop

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 February 7, 2018, 03:03 Total pressure drop & static pressure drop #1 New Member   Join Date: Feb 2018 Posts: 1 Rep Power: 0 hello everyone.. i have a doubt about total and static pressure drops.here is my questions. 1.consider a pipe which having small bend, for that if i measured total pressure drop will give idea about how energy get loss by fluid flow. so we can think about modification on bend or something. but measuring static pressure drop at inlet and outlet is for what purpose? 2. if flow is get recirculated at the bend,then what about the overall total & static pressure drop of the pipe? they will increase or decrease?

April 11, 2018, 03:15
#2
New Member

JD
Join Date: May 2017
Posts: 24
Rep Power: 8
Quote:
 Originally Posted by Aarthar hello everyone.. i have a doubt about total and static pressure drops.here is my questions. 1.consider a pipe which having small bend, for that if i measured total pressure drop will give idea about how energy get loss by fluid flow. so we can think about modification on bend or something. but measuring static pressure drop at inlet and outlet is for what purpose?
If the pipe is horizontal (you're comparing across points at the same elevation), then the static pressure drop and the total pressure drop will be the same. Once you change the elevation, then you'll need to measure the difference between the total pressure to get the pressure drop.

Quote:
 2. if flow is get recirculated at the bend,then what about the overall total & static pressure drop of the pipe? they will increase or decrease?
As you go through more pipe length, you'll have a higher pressure drop. Your compressor/pump will need to overcome the pressure drop in order to maintain the same mass flow rate.

April 11, 2018, 04:07
#3
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Ashok Chaudhari
Join Date: Aug 2016
Location: Pune, India
Posts: 260
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Quote:
 Originally Posted by Aarthar hello everyone.. i have a doubt about total and static pressure drops.here is my questions. 1.consider a pipe which having small bend, for that if i measured total pressure drop will give idea about how energy get loss by fluid flow. so we can think about modification on bend or something. but measuring static pressure drop at inlet and outlet is for what purpose? 2. if flow is get recirculated at the bend,then what about the overall total & static pressure drop of the pipe? they will increase or decrease?
Total pressure can be represented by sum of two terms. Static pressure (which we call pressure head in Bernaulli's eqn) and Velocity head (Kinetic energy).

So For a pipe or bend which have same inlet and outlet diameters, static and total pressure drops should return same value.

I would recommend always go by total pressure drop to compare the energy lost in due to pipe friction or bend or anything else.

Last edited by ashokac7; April 11, 2018 at 05:42.

 April 11, 2018, 04:32 #4 Senior Member   Filippo Maria Denaro Join Date: Jul 2010 Posts: 6,676 Rep Power: 71 Any time that dissipative effects take a role, the total pressure diminuishes as it indicates the total kinetic energy that can be obtained. Dissipation degrades the potential level of kinetic energy as internal energy takes more relevance. CFDger likes this.

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