The simulation of turbulent flow and heat transfer in bare rod bundles and other noncircular passages

The main features of turbulent flow and heat transfer in rod bundle and other noncircular passages are identified. The local mean flow and turbulence kinetic energy distributions are influenced by the turbulence driven secondary flow which is present in the cross plane of all noncircular turbulent passage flows. The main characteristics of secondary flow circulations are noted from a review of the secondary velocity measurements reported for square, rectangular and triangular ducts and a rod bundle passage. The origin of these turbulence driven flows is discussed and their convective effects related to distortions in measured axial velocity and turbulence kinetic energy contours and in wall shear stress and local surface heat transfer profiles. Several generations of calculation method are identified leading to the fourth generation methods which solve numerically, usually by finite differences, the cross plane and axial partial differential transport equations to predict the secondary flows and their influence on local mean flow and heat transfer.