Research

STABLE III Platform CFD Aided-Design

Work developed jointly with the Proudman Oceanographic Laboratory back in 2007 was recently extended in 2011 by Bolaños & Amoudry for submission to the Journal of Atmospheric and Oceanic Technology.  Data from the original studies was significantly augmented in this work, which addressed how the design of a bottom tripod can influence the local effects on the spectrum of near-bed current measurements.  Earlier CFD studies of the STABLE III platform were compared with the latest detailed field measurements and confirmed the value of the Computational Fluid Dynamics approach in early studies and some of the benefits of high-fidelity field measurements from the latest detailed studies of the real system in operation.

Bolaños, R., Amoudry, L. and Doyle, K. 2011. Effects of instrumented bottom tripods on process measurements. Journal of Atmospheric and Oceanic Technology, 28(6), 827-837. 

CFD Solutions Ltd attended the Oceans 07 Conference in Aberdeen supporting John Humphery, Head of Ocean Engineering and Technology at the Liverpool Proudman Oceanographic Laboratory (POL).  John presented a paper, with Dave Jones (POL) and Ken Doyle (CFD Solutions) as a co-authors.

Humphery, J. D., D. S. Jones, and K. Doyle, 2007: The CFD-aided
design of STABLE III, a new platform to study near-bed
turbulent currents and associated sediment dynamics. Proc.
OCEANS 2007, Aberdeen, Scotland, IEEE/OES, 1–6. 

STABLE is an acronym for Sediment Transport And Boundary Layer Equipment and was given to the MkI STABLE apparatus in 1981, which measured near-seabed turbulent currents and associated sediment movement.  In 2004 a successful application was made by POL to the NERC for funding relating to a MkIII version of this technology.

In 2006, CFD Solutions worked closely with POL staff in the early design developments for the STABLE III platform and provided a CFD approach to rapid-prototyping of the device.  A tight development timescale alongside budget constraints and concerns relating to the stability and local flow-field disturbance potential of the platform lead to POL suggesting a computational CFD approach to the design process.

CFD Solutions joined the POL team to subject the initial design proposals to a detailed flow simulation analysis using CFD techniques.  This analysis provided valuable guidance to the design process through the application of fully transient 3-dimensional flow simulations.  Output from the analysis provided drag-force estimates for the highly complex structure, which in turn led to detailed assessments of the system stability and its influence on the local flow field, in both uni-directional tidal flows and in tidal flows combined with wave action.  The CFD analysis also addressed the effects which the structure would have on the local flow field beneath the instrument pack (in the measurement zone) and local wake effects around the instrument pods.

The resulting system design was built by engineers at POL and successfully deployed off Hilbre Island in the estuary of the river Dee, between England and Wales in March 2007.  The instrument was successfully recovered following this initial deployment and data analysis at POL formed the foundation for the latest work by POL staff resulting in submission of the latest paper to the JAOT.