Square-Section Duct 180 Degree Bend
Experiments by Choi
Turbulent flow in a square cross-section duct made of a 180o bend and two
long straight inlet and outlet parts.
3D flow with constant temperature.
Geometry of the Computational Domain
180o bend section connected to straight inlet and outlet tangents, all
of square section: D × D = 88.9 × 88.9 mm.
Centreline curvature radius of the bend: Rc = 3.357D.
Air at standard conditions.
- Kinematic viscosity: = 1.72×10-5 m2/s.
- Inlet bulk axial velocity WB = 11 m/s.
- Reynolds number based on the bulk axial velocity WB:
Re = WBD/ = 56,690.
The following measurements are available for the cross section located at
z = -D. They correspond to a fully developed turbulent in a square section
Contour maps as f(x,y) of:
- First order moments: U, V, W
- Second order moments
- Turbulent kinetic energy: k/WB2 (deduced)
Additional values of k and
issued by numerical simulations are also available in the file input.
Velocity measurements using a rotatable hot-wire probe.
Analyzed but no published values.
Contour maps at 5 different angular positions ( = 0o, 45o, 90o,
135o, 180o) of:
- First order moments:
U/WB, V/WB, W/WB
- Second order moments:
u'/WB, v'/WB, w'/WB,
- Turbulent kinetic energy: k/WB2
Previous and Reference Numerical Solutions
None available yet.
- CHOI, Y.D., MOON C. & Yang, S.H. (1990). Measurment of turbulent flow characteristics of square duct with a 180 degree bend by not wire anemometer. International Symp. on Engineering Turbulenze modelling and measurement, (no page numbers).
- CHOI, Y.D., IACOVIDES, H. & LAUNDER, B.E. (1989). Numerical computation of turbulent flow in a square-sectioned 180 deg bend. J. Fluids Engg 111, 59, (see Chang, Physico-Chem. Hydr. 4, 243, 1983 for expts.).
- SOTIROPOULOS, F. AND PATEL, V.C. (1993). Evaluation of some near-wall models for the reynolds-stress transport equations in a complex 3-d shear flow. Near wall turbulent flows, pp. 987.