Static Pressure calculation

[jmciii]

I need a formula/assistance in calculating static pressure downstream of a radiator. We are building an acoustical housing around an engine and are trying to limit backpressure at radiator to .75" w.c. We have flow rates, discharge areas etc. Any assistance would be greatly appreciated. Thank you.

 

[Combustor1]

There may be some charts you can get hold of. What kind of fluid are you using?

I think you will need to calculate

Velocity pressure = Static and dynamic pressure.

Formula I use for hot gases

P = (ro x V^2)/(2 x g)

you need to get units right - conversions

Velocity Pressure = (ro*V^2/2*gc) ===>

(lbm/ft^3)*((Ft/min)^2)/(lbm-Ft/lbf-sec^2)/(3600 sec^2/min^2)/(lbf/27.72 in WC)*(144in^2/Ft^2)

Double check my units - need to get from lbF/Ft^2 into in. W.C.

Do you know the desity (rho) at flowing state?
Make sure you get all the units correct.

In order to get the velocity right you will need the temp and do the correction for temperature.

Hope that works for you!

 

[jmciii]

Dear Combuster,
Thank you for your reply. Air flow is downstream of a diesel engine radiator. I'm guessing the air temp is around 200+F. We have received some information from a Louver manufacturer that is helping. I'll see how your formulas relate to test data from louver mfg. Thanks again.

JMCIII

 

[jehar]

Hi,
For help with pressure loss in ducting, enclosures, and other pieces, along with help in calculating the system pressures, go to

http://www.HRSGdesign.com,

under Process/Ducting Pressure Losses.
Jack Hardie