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F1: Mercedes W08 Shark fin - Chimney
With the new lower rear wings for 2017, shark fins are used to improve flow the wing, Mercedes thought it needs bodywork in that area why not make it more useful?
A brief test run was made Lewis Hamilton on the first day of testing, with Mercedes Fin/Chimney (could we call it a Frimney?). The fin itself was shorter than a lot of the other teams full sized efforts, additionally the fin was spread open for a chimney-like cooling channel to be usefully made into it. I’ve explained the benefit of shark fins in another post in the EVERYTHING TECHNICAL tribe. So aside from rear wing performance, the device also aids cooling. We use the term chimney, as back before 2009, teams used funnel-like outlets on the shoulders of the sidepods and called these chimneys.
F1 cars carry a lot of cooler to rid the car of heat produced from the power unit. There’s oil and water radiators for the engine, coolers for the hybrid system, a turbo intercooler, hydraulic fluid coolers and an oil cooler for the gearbox. All of these are mounted within the engine cover and sidepods, the air fed through the cooler then has to come out somewhere. This is typically through the back of the sidepods, but as we know teams like skinny sidepods, as it improves airflow to the diffuser and rear wing. So, the bigger cooling outlet the sidepods needs, then the worse the aero will be. Thus, teams look for little places to vent hot air, at the side of the cockpit, around the exhausts and now for Mercedes out the top of the shark fin. There will be higher air pressure within the sidepods, whereas the air just above the fin will be quite clean and at ambient pressure, so the air will want to flow out of the chimney. Also, the vortex produced from the tip of the shark fin in turns, will create lower pressure behind the fin and this will also help pull air from the chimney, further boosting its usefulness. The fin is a big thicker than usual, but I doubt this will create any extra drag or obstruction to the airflow, bearing in mind the position it’s in.
So, Mercedes appear to be on to a winner with this design.