Add a Rotor Rub node to include the effect of potential contact between the rotor and a surrounding housing in the analysis. This is strongly nonlinear effect, and is thus only meaningful for time-domain analysis. The feature is available both as a point and as an edge condition.
In either case, enter a Penalty factor,
kp. The interpretation is slightly different between the two methods. For the penalty method, the penalty factor can be considered as a stiff spring inserted between the rotor and housing when they overlap in order to enforce the contact conditions. A stiffer spring will decrease the overclosure, but is less numerically stable. For the augmented Lagrangian method, the penalty factor is a numeral parameter that affects the convergence rate, but not the accuracy of the converged solution.
In order to take friction between the rotor and the housing into account, select the Include friction checkbox. When selected, enter a
Friction coefficient,
μf. Also, enter the
Effective radius for friction,
Reff. This gives the moment lever for the tangential friction forces, which would typically be radius of the part of the rotor that could touch the housing.