Nigel Macknight, Quicksilver (WSR) Ltd.

The Quicksilver World Water Speed Record Team is using Fluent’s CFD software to optimize the design of what it hopes will become the fastest waterborne craft in history. Quicksilver is powered by a Rolls-Royce Spey turbofan aeroengine and will bid for the World Water Speed Record in the winter of 2001/2002 with team boss Nigel Macknight at the controls. The record stands at 317.60 mph (511.11 kph), and has not been bettered in twenty-one years. Widely regarded as the pinnacle of sporting achievement on water, the World Water Speed Record is very seldom challenged.

This computer-generated artist’s impression of the Quicksilver craft, viewed from the side and from above, reveals the unique configuration of the striking new world water speed record challenger

Lives have been lost in the past, so the design of any new craft must be rigorously tested. Wind tunnel testing has provided some, but not enough, answers to the Quicksilver team’s questions about how a craft behaves when it is traveling at such high speeds across the unpredictable surface of a large lake. Coniston Water, in England’s picturesque Lake District, has been chosen as the venue for the bid. Using FLUENT, and taking advantage of parallel processing, the team is assessing airflow behavior across the upper and lower surfaces of Quicksilver at high speeds. There is a strong tendency for this type of craft to experience a ‘flip-over’ if stability is lost, even for a brief moment.

The design team is particularly wary of vortices, which can be shed from the forward part of the craft and then reattach themselves further back to cause unwelcome lift and instability. CFD studies are allowing the team to understand more fully the behavior of these vortices, and their interactions with the craft’s hull at high speeds, prompting subtle changes to the baseline design. In addition, Quicksilver’s designers are simulating the airflow over and around the cockpit canopy, and into the engine air intake situated immediately behind it. They are refining the craft’s shape to achieve optimum performance in this vital area, because the engine will only operate at maximum efficiency if air is delivered smoothly across the full area of the compressor face, and the presence of the cockpit canopy so close to the intake is a potential source of airflow disturbance.

Vertical plane showing velocity vectors

Other design areas in which FLUENT will play a key role are engine cooling, simulation of water surface wake effects as the craft makes the critical transition from displacement to planing condition, cooling of on-board electronic systems, and assessment of the interaction of the engine jet exhaust with the rear-mounted horizontal and vertical aerodynamic stabilizers. Fluent has become a Technical Partner of the Quicksilver team, joining two other participants in the team’s CAD operations, Parametric Technology Corporation and hardware supplier OCF PLC. Further details can be found on the official Quicksilver web site at www.quicksilver-wsr.co.uk.

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