Multiple laminar flows through curved pipes (Q1081449)

The Dean problem of steady viscous flow through a coiled circular pipe is studied numerically for a large range of Dean number and for several coiling ratios. We find that the solution family, as parameterized by Dean number, has numerous folds or limit points. Four folds and hence five branches of solutions are found. We speculate that infinitely many solutions can exist in this family for some fixed value(s) of D. More resolution and higher accuracy would be required to justify our conjecture and to find the rule of formation of new solution branches.