AeRowFin
6Pages

MAKE YOUR BOAT FLY! – the scientific principles explained WHAT IS AEROWFIN? AeRowFin is an amazingly precise and powerful steering system. What’s wrong with current steering systems? Compact, economical, elegant and robust, it increases boat speed by enhancing control, improving stability and reducing overall drag. Hydrodynamics provides a better way These claims are underpinned by solid science, established technology and, of course, by AeRowFin’s outstanding, proven performance. But how does AeRowFin really work? That underlying science is Hydrodynamics, a branch of the rigorous parent science of Fluid Dynamics and close twin of Aerodynamics. Aircraft wings are optimised by the intelligent application of advanced Fluid Dynamics. By the same procedures, AeRowFin is designed to optimise the performance and control of racing shells. How AeRowFin works And how does this reduce drag, increase stability and improve boat s

WHAT’S WRONG WITH CURRENT STEERING SYSTEMS? To turn a boat requires a side force. There are two ways to provide this force: deflect a blunt object sideways to increase drag on that side; or use a properly–designed steering foil to generate hydrodynamic ‘lift’ with no extra drag. Most steering systems employ two flat plates – a big one to keep the boat heading straight and a small one to make it turn. When turning, the small plate must first overcome the large one’s resistance. This conflict is neither efficient nor sensible. First the fin resists the rudder component, then loses its grip...

HOW AEROWFIN WORKS AeRowFin is particularly well designed. To steer in either direction a foil should start off symmetrical – like an aircraft’s stabiliser fin. Simple symmetrical foils can generate large amounts of lift when inclined to the oncoming flow and can be quite efficient. But a large foil mounted on a pivot under a shell’s tightly curved hull has messy flow around its root (against the hull) and weed and detritus can jam in that gap. The steering pivot encounters large side and bending forces and few such systems exist, with few shells built to take them. Even when geared down,...

HOW DOES AEROWFIN REALLY WORK? The fastest flow over a well-designed foil occurs in the first half of its chord – between leading edge and mid-line. So, contrary to what one might expect, the lowest pressure and thus the greatest side force (lift) is centred at about 25% back from the leading edge, not on AeRowFin’s steering element. Even surface lift on a symetrical foil But we turn that tab to generate the lift by which we steer, so why will we feel no load there? Fluid Dynamics can be deeply counter intuitive and this is no exception. We tend to think that rudders “push water aside”, and...

DRAG REDUCTION THROUGH COURSE IMPROVEMENT The poor controllability of conventional systems demands large and frequent corrections to hold a course. These corrections lengthen the distance rowed and impair speed through the poor hydrodynamics of those steering systems and the drag induced as the boat side-slips with each change in direction. All of the energy thus lost is permanently stolen from the work of the crew. AeRowFin's efficient action greatly reduces these sources of drag. It ensures that the boat wanders less and less often. It is highly responsive, so corrections happen sooner...

Until we developed AeRowFin, to change an unsteerable boat into the winning platform for Sydney 2000's gold medal eight, the rowing world was content to steer with two slabs of metal, or of ill-shaped plastics, whose form would earn the derision of any competent fluid dynamicist. When steering cost us the race we used to blame the cox. That was cruel then. It makes even less sense now. AeRowFin is a genuine race-winner It is a legal performance enhancer with a proven record. Can you afford to be without it? STEERING WITH AEROWFIN Your first use of an AeRowFin will be a real eye-opener. Once...