Turbulent flow in a duct with cusped corners

An orthogonal-cuvilinear-mesh-based finite-volume calculation method has been applied to the problem of fully developed turbulent flow in the tricusped cornered duct formed when parallel circular rods touch in triangular array. Algebraic stress relations combined with the k-epsilon turbulence model are used for calculation of the required stresses. A single circulation of turbulence-driven cross-plane secondary flow from the core into the duct corner has been predicted in a one-sixth symmetry region of the duct and the convective transport effects of this flow are seen to have much influence on local mean flow distributions. The turbulence field predicted by the k-epsilon model showed significant damping in the cusped corner region where turbulent viscosities approached the laminar value. Satisfactory agreement was obtained with the limited local and overall mean-flow measurements available.