AS/NZS 1170.2 Cfig for Cylindrical Tank 1

[wsmith22]

Can someone please give me some guidance in determining Cfig for a pressure vessel? Do you compute Cp1(θb) for various angles and sum the results to obtain Cfig? I assume this value is then added to Cfig drag force .63 to obtain the overall Cfig used in the design wind force equation.

Thank you,
Wes

 

[Settingsun]

It appears to me that the answer is just the 0.63 number, if you're after total load eg for foundation design. And c/b ratio (within the stated limits) appears not to affect this.

Seems low compared to building structures though. Section E3 might serve as a cross-check.

 

[apsix]

Cfig = 0.63 compares well with Table E3, where Cd for cylinders can be as low as 0.6 when b*V > 10 m2/s.

 

[BJI]

If this is for a pressure vessel you would be better off following the guidance in AS1210 Appendix J, Table J2. This applies to aspect ratios more suitable to pressure vessels and incorporates vortex shedding effects (built in based on typical vessel attachments).