General information

SlenderFlow software uses slender-body theory to calculate the flow of water around ships. It is developed by Dr Tim Gourlay at Perth Hydro, and used for our ship hydrodynamics consulting. As a potential-flow code, it is very numerically efficient, with computation times typically a fraction of a second.



Ship types

SlenderFlow may be used for any displacement (non-planing) vessel, including ocean-going commercial and military vessels, European inland vessels, catamaran ferries and trimaran ferries.

Commercial track record

The methods in SlenderFlow have been successfully used in many commercial projects, including:

Model-scale validation

SlenderFlow methods have been validated against a wide range of model tests from the European shallow-water towing tanks at Flanders Hydraulics, DST Duisburg and BAW Hamburg. The international "PreSquat" blind validation workshop of 2013 showed that SlenderFlow methods produced consistently accurate squat predictions.

Full-scale validation

Full-scale ship motion trials have now been undertaken on over 60 cargo ship transits through shallow channels in Hong Kong, Torres Strait, Geraldton and Fremantle. The results have been used to validate and refine SlenderFlow for application in shallow shipping channels.

See our ship UKC video , validation articles and simplified UKC guidelines

Bathymetry types

Method options

Image credits

Freight Ro-Ro in Thames Estuary, depth 16 m, speed 20 knots, courtesy of John Clandillon-Baker.

© 2022 Perth Hydro Pty Ltd.