Tug powers

Prediction of aero and hydrodynamic forces acting on ships navigating on the river Elbe in order to estimate the required tug power

As a consequence of an increasing demand for transport volume at sea, there is a recognizable trend towards larger vessels which have larger areas being exposed to wind and current, leading to higher wind and current loads. Thus, it is getting increasingly difficult to determine the required tug power in confined waters.

The objective of this project is to calculate coefficients of the drag and lateral forces as well as the yaw moment of selected ships for various angles of attack on the river Elbe by means of computational fluid dynamics. The results are used to build up a database and a tool for the interpolation of coefficients matching arbitrary ship dimensions and boundary conditions.

The prediction of a valid tug power also requires knowledge of further nautical aspects, such as the available tugs, towing angles, available space and harbour restrictions. The developed software programme will be the basis on which a nautical engineer can estimate the tug power.

 SQUAT

Within the SQUAT project, the squat of ships as a result of shallow water conditions on the River Elbe is calculated. The calculations are performed by means of a Finite Volume Method, which employs the Reynolds-Averaged-Navier-Stokes-Equations (RANSE) and are compared to the measuring data provided by the Development Centre for Ship Technology and Transport Systems (DST) and the Federal Waterways Engineering and Research Institute (BAW).