Measurements of Transient Flow Induced by a Berthing Barge in a Towing Tank

Abstract

A test program was conducted to collect essential experimental data required to validate a ship-berthing simulation model based on the Chimera RANS/free­surface technique. This technique has demonstrated a unique capability of describing critical features of the transient flow induced by a berthing ship. Validating experiments were conducted in a shallow water basin. A model barge was drawn transversely through calm water by a towing carriage toward a solid, vertical quay wall in a manner similar to a regular berthing process. The transier.t water flow induced by the moving barge was recorded with acoustic doppler velocity meters mounted on the barge and at six fixed locations within the basin. Flows leading, trailing, passing under the keel and around the ends of the barge were observed. The test parameters considered included approach speed, water depth and angle of approach. The flow pattern at the free surface was observed using floating ping-pong balls, while flow pattern at the bottom of the basin were observed using neutrally buoyant beads. A number of noteworthy findings and observations relating to flow and reversal of flow are included in the remarks section of this paper. The model basin tests produced good comparisons between measured current velocity and water currents predicted by the simulation model. The large volume of water trailing the barge was shown to contribute significantly to the resulting berthing energy, especially in those runs where water depth was small compared to ship draft.