Hi all,

Can anybody point me to experimental or simulation data for Laminar flow in a smooth 180 degree bend. I searched the net & some journals but can't exactly find what I need.

Thnx

Abhijit

is it a curved duct? circular or rectangular duct?

Hi,

Thnx for ur reply. yes it's a curved duct,It's like a U shaped bend. Well my code is 2-D so I guess the shape of cross-section does'nt matter. (Although flow in 180 deg. bend is never 2d bcos of secondary flow). Let me know if you can point me to such data.

Thnx

Abhijit.

dear Abhijit,

you can try this one, although it is not a 2d flow, the duct is of large aspect ratio:

Kelleher, M.D., Flentie, D.L. and McKee, R.J. (1980). "An Experimental Study of the Secondary Flow in a Curved Rectangular Duct." Transactions of ASME Journal of Fluids Engineering, Vol. 102, March 1980.

thanks. regards, yfyap

Dear yfyap,

Is there any well documented data for a rectangular 180 degree bended duct ?

Thanks

Li

try these, rather old, but they are still used for code verification.

Ghia, K.N. and Sokhey, J.S. (1977). ~{!0~}Laminar Incompressible Viscous Flow in Curved Ducts of Regular Cross Sections.~{!1~} Transactions of the ASME Journal of Fluids Engineering, pp. 640-648.

Humphrey, A.C., Taylor, A.M.K. and Whitelaw, J.H. (1977). ~{!0~}Laminar Flow in A Square Duct of Strong Curvature.~{!1~} Journal of Fluid Mechanics, Vol. 83, Part 3, pp. 509-527. (Experimental and computational data)

Taylor, A.M.K.P., Whitelaw, J.H. and Yianneskis, M. (1982). ~{!0~}Curved Ducts with Strong Secondary Motion: Velocity Measurements of Developing Laminar and Turbulent Flow.~{!1~} Transactions of the ASME Journal of Fluids Engineering, Vol.104, pp. 350-358.

an exact solution for fully developed flow is given in: White, F.M. (1991). ~{!0~}Viscous Fluid Flow.~{!1~}2nd edition. New York: McGraw-Hill, Inc.

hope this helps.

sorry for being curious, what are you working on? laminar/turbulent flow in curved ducts?

regards, yfyap

Hi yfyap,

I am testing a algorithm that was formulated on non-staggered structuted grid.I am trying to see it's use on non-staggered unstructured grids(triangle elements). Situations where steep pressure gradients exists are acid test cases for non-staggered formulations. My code does show smooth pressure distribution for 180 deg. bend. It also seems to make sense. But validation is the final test that code must pass.

Anyway thanks for the references.

Abhijit

Thank you very much indeed. I haven't decided what kind of flow I should simulate the next yet. I am thinking that a 180 deg. sharp turn may be a good candidate. I would prefer a case with some new experimental data including the turbulence intensities and heat transfer.

Is there any such kind of case available?

Li

dear Abhijit, thanks for your generosity in sharing the information. if you happened to run your code for 3d flow (curved rectangular duct), besides those data that i mentioned, i have actually had my own numerical data on such flow (parabolic flow). please let me know if you need it. thanks, regards, yfyap

dear Li Yang, sorry, i'm afraid i don't have these data. i have only worked on curved ducts. regards, yfyap