• Adrian Newey and the bar-headed goose

    The April edition of Motorsport Magazine contains a fabulous F1 season preview from Mark Hughes, which includes the news that Adrian Newey has recently been taking a break in the Himalayas.

    Now, whilst it’s likely that the principal purpose of this expedition was to enlighten the Dalai Lama on the importance of using large-eddy simulation to understand the interaction of brake-duct winglets with the spat vortex, it’s also possible that Adrian was drawn by the legendary bi-annual migration of the bar-headed goose.

    These birds are amongst the highest-flying in the world, and travel across the Himalayas in a single day. William Bryant Logan claims in Air: Restless Shaper of the World (2012), that “the bar-headed goose has been recorded at altitudes of over thirty-three thousand feet. This is the altitude where your pilot remarks that the outside temperature is 40 degrees below zero, where the great fast-flowing rivers of the jet streams set weather systems spinning. The air here contains only one-fifth of the oxygen near sea-level, where the goose winters in lowland India wetlands and marshes. Yet in the space of a few hours the bird can fly from the wetlands to the top of the high peaks and then out onto the world’s largest high plateau. There are lower passes through the mountains, but the goose does not take them. It may even preferentially go higher.”
    However, research led by Bangor University tracked the bar-headed geese with GPS as they migrated over the Himalayas, and reached the following conclusion in 2011:

    “Data reveal that they do not normally fly higher than 6,300 m elevation, flying through the Himalayan passes rather than over the peaks of the mountains…It has also been long believed that bar-headed geese use jet stream tail winds to facilitate their flight across the Himalaya. Surprisingly, latest research has shown that despite the prevalence of predictable tail winds that blow up the Himalayas (in the same direction of travel as the geese), bar-headed geese spurn the winds, waiting for them to die down overnight, when they then undertake the greatest rates of climbing flight ever recorded for a bird, and sustain these climbs rates for hours on end.”

    Furthermore, The roller-coaster flight strategy of bar-headed geese conserves energy during Himalayan migration, (Science, 2015), suggests that “geese opt repeatedly to shed hard-won altitude only subsequently to regain height later in the same flight. An example of this tactic can be seen in a 15.2-hour section of a 17-hour flight in which, after an initial climb to 3200 m, the goose followed an undulating profile involving a total ascent of 6340 m with a total descent of 4950 m for a net altitude gain of only 1390 m. Revealingly, calculations show that steadily ascending in a straight line would have increased the journey cost by around 8%. As even horizontal flapping flight is relatively expensive, the increase in energy consumption due to occasional climbs is not as important as the effect of reducing the general costs of flying by seeking higher-density air at lower altitudes.

    “When traversing mountainous areas, a terrain tracking strategy or flying in the cool of the night can reduce the cost of flight in bar-headed geese through exposure to higher air density. Ground-hugging flight may also confer additional advantages including maximizing the potential of any available updrafts of air, reduced exposure to crosswinds and headwinds, greater safety through improved ground visibility, and increased landing opportunities. The atmospheric challenges encountered at the very highest altitudes, coupled with the need for near-maximal physical performance in such conditions, likely explains why bar-headed geese rarely fly close to their altitude ceiling, typically remaining below 6000 m.”

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  • Driver core-skin temperature gradients and blackouts

    Whilst it is highly beneficial to reduce the surface-to-bulk temperature gradient of a racing-tyre, the same cannot be said for the cognitive organisms controlling the slip-angles and slip-ratios of those tyres.

    A 2014 paper in the Journal of Thermal Biology, Physiological strain of stock car drivers during competitive racing, revealed that not only does the core body temperature increase during a motor-race, (if we do indeed count a stock-car race as such), but the skin temperature can also rise to such a degree that the core-to-skin temperature delta decreases from ~2 degrees to ~1.3 degrees.

    The authors suggest that a reduced core-to-skin temperature gradient increases the cardiovascular stress “by reducing central blood volume.” Citing a 1972 study of military pilots, they also suggest that when such conditions are combined with G-forces, the grayout (sic) threshold is reduced.
    Intriguingly, in the wake of the Fernando Alonso’s alien abduction incident at Barcelona last week, they also assert that “A consequence of this combination may possibly result in a lower blackout tolerance.”

    Source: mccabism

  • Audi Old Spock battles New Spock – Coolest Car Commercial Ever

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    Leonard Nimoy sadly passed away this week. One of my favourite car adverts to date has got to be the Audi commercial from 2013, starring both Leonard Nimoy and Zachary Quinto. It’s got two Spocks, a dig at Mercedes, Leonard Nimoy swearing and best of all, an awesome impromptu rendition of the “The Ballad of Bilbo Baggins” by Leonard Nimoy. Brilliant.

    Live long and prosper!

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