Poiseuille_Flow_Pressure_Inlet

brossi1129 · October 21, 2014, 20:42

This is a very simple Flow Model. I am creating it to try and help myself understand a flow problem given to me for an Independent Study.

-I have a simple Pressure inlet with a Gauge Pressure of 2000 pascals and a pressure outlet of 0 gauge Pressure.
-My operating Conditions show that I am using an Operation Pressure of the standard 101325 Pascals.
-I have simple geometry of a 1/2 meter by 4 meter pipe.
-One inlet One outlet with simple laminar steady flow conditions

I am curious as to why the fluid velocity calculated in the pipe is 63 meters per second!!??
Please let me know what I am doing wrong.
Thank You for Your Time

swiftaircraft · October 22, 2014, 04:59

I am assuming that you have used air as the medium with the default density at 1.225 kg/m³. From non CFD methods then forcing the Reynolds to 1000 (in the laminar zone) the velocity is 80.84 m/s to produce the dP that you have specified. So your prediction of 63 m/s does not seem that far off. If I force the Re to 633 then I can match your 63 m/s number. What fluid properties have you assumed?

October 21, 2014, 20:42	Poiseuille_Flow_Pressure_Inlet	#1
brossi1129 New Member Bryan Rossi Join Date: Oct 2014 Posts: 3 Rep Power: 12	This is a very simple Flow Model. I am creating it to try and help myself understand a flow problem given to me for an Independent Study. -I have a simple Pressure inlet with a Gauge Pressure of 2000 pascals and a pressure outlet of 0 gauge Pressure. -My operating Conditions show that I am using an Operation Pressure of the standard 101325 Pascals. -I have simple geometry of a 1/2 meter by 4 meter pipe. -One inlet One outlet with simple laminar steady flow conditions I am curious as to why the fluid velocity calculated in the pipe is 63 meters per second!!?? Please let me know what I am doing wrong. Thank You for Your Time

October 22, 2014, 04:59		#2
swiftaircraft Member David Stanbridge Join Date: Apr 2010 Location: Norwich, UK Posts: 59 Rep Power: 16	I am assuming that you have used air as the medium with the default density at 1.225 kg/m³. From non CFD methods then forcing the Reynolds to 1000 (in the laminar zone) the velocity is 80.84 m/s to produce the dP that you have specified. So your prediction of 63 m/s does not seem that far off. If I force the Re to 633 then I can match your 63 m/s number. What fluid properties have you assumed? __________________ David Stanbridge Swift TG Solutions Limited www.swifttgsolutions.com