HIPER 2021

We are looking forward to meeting you at the HIPER 2021 in Tullamore (Ireland). Dr Thomas Hildebrandt is one of the speakers. He will present two papers “Advanced CFD-based Design Approach for High-Performance Sailing Catamarans” and “Parametric Modeling and Hydrodynamic Optimization of an Electric Catamaran Ferry based on Radial Basis Functions for an Intuitive Set-up “
 
Date: 13. – 15. September 2021
Location: Tullamore, Ireland
 

Advanced CFD-based Design Approach for High-Performance Sailing Catamarans

Abstract:
This paper aims to examine the performance effect of combining both daggerboards and vestigial keels as underbody appendages on an existing sailing catamaran design which previously had either only keels or only daggerboards. The impact of the underbodies on sailing and rudder performance is explored in detail in a range of wind conditions, making use of a velocity-prediction-program (VPP) in a RANSE-CFD code. Several variations to the appendages design and position are investigated to find a trade-off between the protective benefits of a keel and the superior performance of a daggerboard.
 
Authors:
Sven Albert, NUMECA Ingenieurbüro, Altdorf b. Nürnberg/ Germany
Rodrigo Corrêa, NUMECA Ingenieurbüro, Altdorf b. Nürnberg/ Germany
Thomas Hildebrandt, NUMECA Ingenieurbüro, Altdorf b. Nürnberg/ Germany
Anton Du Toit, Du Toit Yacht Design, Cape Town/ South Africa
Samantha Krenski, Du Toit Yacht Design, Cape Town/ South Africa
 

Parametric Modeling and Hydrodynamic Optimization of an Electric Catamaran Ferry based on Radial Basis Functions for an Intuitive Set-up

Abstract:
The paper presents a design study for an electric catamaran ferry undertaken at the tender stage. Starting from a baseline created to comply with the operational requirements of the future owner, a parametric modeling and hydrodynamic optimization campaign was conducted with the aim of further reducing energy consumption as much as possible, the weight of batteries and the range of a purely electric ferry being of key importance. Due to the short time available in early design, here just three weeks, a partially-parametric modeling approach using Radial Basis Functions was selected. The ferry being relatively short despite considerable displacement when fully loaded and the clearance of the demi-hulls being small, a free-surface RANS code with free trim and sinkage was employed for the hydrodynamic optimizations. The practical approach of modeling and optimization will be explained and illustrated. Results for several displacements at different speeds will be presented, showing the tangible improvement realized within a highly concerted team effort.
 
Authors:
Sven Albert, NUMECA Ingenieurbüro, Altdorf/Germany
Erik Bergmann, FRIENDSHIP SYSTEMS, Potsdam/Germany
Stefan Harries, FRIENDSHIP SYSTEMS, Potsdam/Germany
Thomas Hildebrandt, NUMECA Ingenieurbüro, Altdorf/Germany
Massimo Kovacic, Yachtwerft Meyer, Bremen/Germany