F1 Fanatic guest writer John Beamer looks at the technology of the 2009 F1 cars, starting with those eye-catching front wings.
Contrary to what many feared a few months ago, 2009 will be a bonanza for F1 technical aficionados. The lower (and flatter) front wing, higher nose and deletion of various aerodynamic paraphernalia circling the chassis allow a much better sense for the how F1 engineers channel airflow below the chassis – take a look at any low frontal shot of a 2009 F1 car for a visual treat.
Also the aerodynamic variation among teams is stark, at least at this early stage of the season. As the year progresses designs may start to converge but, rest assured, technical innovation in F1 is alive and well.
In this article I’ll look at some of the aero innovations found around the front wing and nose. Before the season starts we’ll take a look at both the mid-region and rear of the car. Naturally it is impossible to comment on all the changes that take place so I’ve picked out some highlights.
The front wing looks vastly different to its 2008 cousin. For a start it is lower (at its lowest 75mm above the reference plane, rather than 150mm) and has an FIA specified central section that actually produces lift to reduce aero sensitivity. Under the old regulations the ‘U’-shaped central section produced a lot of downforce and was susceptible to performance degradation when following a car. Although the flat central section is FIA mandated, teams have considerable freedom to innovate towards the extremities of the wing.
Also the wing is wider – it now spans the width of the car – which gives rise to a different wheel-wing design philosophy. The narrower wing of 2008 meant that the end plates were designed to force air inside the tyre line to reduce drag. This year the wider wing forces designers to use end plates to scoop air around the outside of the tyre – this is why the front wing looks boxy compared to last year’s sleek look. While this sounds a trivial change it the context of the sport it is important. In the last five years teams have developed advanced tyre modelling software that now needs to handle this new design philosophy. Tyres contribute 30-40% of drag so getting the wheel-wing interaction right is important.
Despite its current performance woes McLaren has been aggressive with the front of the car. The MP4-24 is the first to sport a four-element front wing for maximum downforce. The flaps integrate with an intricate endplate that is not only designed to direct airflow around the wheel but also to seal the underside of the wing.
Sealing is accomplished a couple of ways. First the semi-circular Venturi channel is retained. This channel captures and controls a vortex under the endplate’s footplate which prevents high pressure air from spilling under the wing. Also a series of fences can be seen on the inner side of the endplate directly in front of the tyre. These fences manage the air under the wing to prevent the flow from being overly disturbed by air that is pushed off the front of the tyre.
This air is high pressure and as such tends to seep under the main plane harming downforce. Deploying such fences is prone to sensitivity under cornering as the air flow changes easily, but McLaren must feel that the downforce gain offsets any handling issues. The new McLaren wheel fairing, with the forward facing duct, is also a consequence of the new rules which means that air is channelled to the outer side of the tyres. To ensure the car is legal the width must be slightly narrower to allow the fairing to jut out.
Brawn GP (above) has taken a novel approach to its front wing and eschews traditional endplates. A fence does protrude from the footplate but it isn’t connected to any flaps. Cascade flaps sprout from the main plane and flick upwards to prevent it spilling from the cascade to the plane. The main flaps are supported by a triangular section rising from the footplate – usually this section would be oblong to form the endplate. This allows the high pressure air to roll off the top of the flaps where it is channeled outside the wheel reducing drag – it will be interesting to see if other teams follow Brawn GP’s lead.
A striking design difference among teams is the shape, size and positioning of the nose cone – from the raised point preferred by Toyota to the bulbous droop from Brawn GP.
A higher the nose funnels more air under the chassis to the splitter. Controlling the airflow in this region is important for feeding the floor and increasing consistency of the diffuser. In contrast a lower nose impedes airflow but can create a Venturi channel between the wheels to add downforce - this is what Brawn GP has done.
The air is forced through a gap between the nose and the standard front wing plane and then expands in the space behind creating a low pressure zone. With this configuration more work is required to feed the floor evenly as evidenced by the complex undersides of the Williams and Brawn cars. A close look at the Williams reveals a ‘snow plough’ arrangement above the splitter to scoop up the fast flowing air under the chassis and direct it to the floor. Vortices spin off the plough under the floor to the diffuser causing a dramatic increase in downforce.
Some teams employ a higher nose to create design loopholes in which vanes and bargeboard type elements are deployed. BMW, for instance, has a pair of vanes appended to the lower outer section of the nose that drop 10cm below the monocoque. These function like the forward turning vanes that were ubiquitous last year – encouraging flow on the outer side of the vane towards the sidepod undercut.
Most teams elect to keep the nose cone less than the regulatory maximum so as to have the option of appending strakes to the nose. These create tip vortices that control the flow over the mid-region of the car towards the rear wing.
One reason why some teams may choose a fat nose is to house KERS batteries. These are exceptionally heavy and placing them aft will upset the weight distribution of the car. Although placing the batteries in the nose will raise the centre of gravity the additional forward weight bias should more than offset this.
In the front part of the car there is a surprising amount of aero development. As the season matures some design convergence will no doubt occur. However, the beauty of new regulations is that all teams start from the same baseline and the pace of change in the early races should be substantial. And for those of us who love F1 because of the technical challenge that is extremely good news.
This is a guest article by John Beamer. If you want to write a guest article for F1 Fanatic you can find all the information you need here.
Images (C) Ferrari spa, Brawn GP, Toyota F1 Worls