URGENT- Pressure drop across flexible bellows connection 1

[d1010223]

I've been asked to assess the reduction in cooling air flow due to the use of a flexible bellows joint between my ventilation duct and a locomotive traction motor...I want to set up a spread sheet to show reduction in area (due to pinching/closure due to missalignment) and resulting flow. I desperatly need a f or k factor or maybe a new equation to work out the pressure drop across the bellows and resulting reduction in airflow.


Any assistance would be greatly appreciated!

Adrian

 

[lilliput1]

SMACNA HVAC Systems Duct Design 1990 Figure 14-3 on page 14.9 charts duct friction loss correction factors for rough, medium rough, old, new and smooth ductwork at various sizes. Table 14-1 page 14.8 list flexible duct as rough category.
You should also account for elbows by inputing them as equivalent lengths.