Hydrodynamic forces and ship motions induced by surges in a navigation lock

This thesis treats the fluid and ship motion in a navigation lock and their mutual interaction as caused by surges, which occur in the chamber during filling or emptying. The other phenomena, which possibly play a role during these processes are ignored. The considerations of this treatise hold good for one ship in the chamber of the navigation lock, which is moored off such, that its displacement in the horizontal plane is negligible. The first simplification is less essential; with regard to the second simplification the theory presented can be extended relatively simply for longitudinal displacement of the ship. Furthermore no attention is devoted to various filling and emptying systems and their possible consequences for the theory; at any instant a practically homogeneous horizontal velocity distribution is assumed at the doors. On the basis of the results obtained in the chapters 6 and 7, it can be concluded, that for the higher frequencies, which can occur in a navigation lock, the theory derived in chapter 3 means an improvement with respect to the approach now in use. Moreover using the results of chapter 7 a reasonable approximation to the cross-forces can be found. The harmonic solutions, given ~n the chapters 6 and 7, cannot be used for the computation of a concrete case. This is caused by the quasilinear character of the various equations due to the continuously changing water level in a ship lock. Therefore, in chapter 8 the integration of the equations is carried out in a numerical way. In the integration it is assumed, that the velocities remain small, so that some quadratic terms in the equations of motion can be neglected. The computational scheme is chosen such, that the detrimental effect of the truncation error is eliminated; its stability is investigated in appendix c. The program is tested by means of the results of an experiment with a transient with arbitrary shape. Finally the program is used for a specific case. In this case the cross-forces as caused by the translatory waves proved to be an order of magnitude smaller than the longitudinal force.Hydraulic EngineeringCivil Engineering and Geoscience