Added to its 46 years of propeller design, Mark Phare looks at the new geometry modelling software enabling Teignbridge Propellers to deliver comprehensive propulsion solution packages
Teignbridge is known and respected across the world as a trustworthy and reliable designer and manufacturer of propellers and stern gear. However, this latest technological implementation has taken propeller design to new levels.
However in recent years it has become clear that the market demands more than reliable designs and high quality precision components. Customers are pushing the boundaries regarding what they want to achieve from their propulsion packages.
Generally, the main ingredients are increased performance, reduced vibration and/or increased fuel economy. In addition they want technical support and the confidence that the designs will translate into the real world and deliver the performance envisaged .
Teignbridge recently completed a £3m research project into propeller efficiency and the legacy of that project is a highly qualified and experienced design team supported by advanced computational fluid dynamic simulation CFD (Star CCM+), unique propeller design optimisation software, cavitation modelling, wakefield propeller analysis, finite element analysis and a propulsion research vessel that can validate the theoretical designs in real life at sea and scale. No other propeller designer and manufacturer has this unique combination of assets that are available to all customers.
Teignbridge is able to combine over 45 years of experience across a number of sectors with cutting edge technology to provide customers with unrivalled, high efficiency propeller designs. Using three large volume 3D printers and a 5-axis CNC pattern mill, it is possible to produce highly accurate patterns, ensuring that the CNC machined propellers are a faithful implementation of the intended design, delivering the predicted performance.
Propeller performance can be defined by a number of metrics, from hydrodynamic efficiency and cavitation susceptibility to mechanical strength and noise and vibration. These performance criteria often pull in opposing directions, such that the right balance needs to be driven by the specific, weighted requirements of each customer and the propeller geometry defined to meet that specification. Until recently, propeller design was driven by empirical data and long duration trial and error improvement and was viewed as a dark art by those on the outside looking in. Teignbridge utilises new powerful simulation tools to understand the interaction between the propeller structure and the high-velocity fluid flowing around its complex surfaces.
In-house, genetic algorithm driven propeller design optimisation is a truly remarkable asset. Using this approach 500 design iterations can be generated and evaluated in CFD during a 48 hour period. Optimisation for performance can be tuned for efficiency, cavitation, noise and more. The methodology can be run on the Teignbridge in-house 20 core workstation or via cloud computing.
Another feature of our computing capabilities is the wake field analysis which allows us to predict the flow of water around the hull and through the propeller, truly accounting for the real operating conditions. Propeller design optimisation by this method refines the propeller design beyond that of a standard approach, combining the best of experienced design engineers and advanced numerical simulation.
This integrated approach to propeller design starts by assessing the mission profile and/or history of vessel and the propulsion specification. The propeller is then designed for efficiency utilising computational fluid dynamics (CFD): Star CCM+ and genetic algorithm driven design refinement.
We can then undertake fully transient CFD wakefield simulation and wakefield design adaption, followed by our 1D ship simulation software which uses in-house HEPS Sim tool: Matlab + Simulink and off-design optimisation. If required we can validate the design by manufacturing the propeller and undertaking physical testing on our research vessel HRV1 which is based in Torbay.
HRV1 is a uniquely designed propulsion research vessel. Whilst scale model propellers can be tested in test tanks, HRV1 allows the testing of full-scale propellers, therefore reducing scale effects with propeller diameters up to 1200 mm vs. tank testing at 250 mm. By testing a full-scale propeller we can de-risk innovative ideas before introducing to the market and test a customer’s propeller designs before the vessel completes construction.
Also, undertaking numerous physical trials and comparing the results with our CFD predicted results means that we have an exceptional opportunity to refine our CFD numerical analysis comparison and verification. No other propeller designer and manufacturer has this unique set of tools at their disposal.
Of course, not all customers will require such a sophisticated approach when ordering a new propulsion system, so Teignbridge has the flexibility to provide a wide range of propulsion design services from a rapid propeller sizing, to the inclusion of a selection of, or all of, the previous described tools. Teignbridge holds patterns to make over 2000 different propeller designs, so if your requirement is a rapid replacement propeller, the chances are that we will have a suitable pattern at our disposal for a timely delivery no matter where your vessel is located.
Although we always recommend a custom designed propeller to achieve optimum performance. Join our ‘Club Teign’ to ensure that you receive a preferential service and are prepared for what ever the season throws at you. If you would like to improve the performance or economy of your yacht, we can at the same time offer a custom designed high performance C-Foil propeller option. You will then have the peace of mind that should your propellers become damaged, you won’t have to wait six weeks for a replacement and reduce any unnecessary down time during a busy season.
For more details Tel: +44 (0)1626 333377 or visit www.teignbridge.co.uk
DESIGN OPTIMISATION
Teignbridge is at the forefront of technology used in the design, performance prediction with simulation software and artificial intelligence driven geometric modelling for design optimisation.