It probably hasn’t escaped the attention of hypermilers that there is something quite natural about pulse & glide. After a search through this and the cleanmpg websites, it appears that such similarities to natural behaviour may not have been highlighted previously. ‘Intermittent locomotion’ is widespread in nature. Take a look at a robin hopping across the lawn or squirrel climbing a tree, for example. The following extract from this article on bird flight explains how birds very between what they call ‘flap-gliding’ and ‘flap-bounding’ types of intermittent flight. You can’t help noticing some conceptual similarities to pulse-gliding methods here. Could budding hypermilers learn lessons from watching natural examples around us? “Most species of birds do not flap their wings continuously during flight. Rather, they exhibit one of two intermittent flight patterns: flap-gliding and flap-bounding. Mathematical models predict that flap-bounding is energetically cheaper than continuous flapping flight at high speeds, while flap-gliding is more efficient than continuous flapping at low speeds. However, few species of bird exhibit both types of intermittent flight, so flap-bounding may be a compromise between the need to maintain muscle contractions at an optimal velocity and the need to vary power output and flight speed.†Flap-gliding flight path (top) and flap-bounding flight path (bottom) Source: http://www.biology.leeds.ac.uk/staff/jmvr/Flight/PWV/index1.htm If these were pulse-glide diagrams, which could or should we be using? Intermittent flight is also seen in bats. It appears that scientific study of intermittent locomotion has only relatively recently been advanced by rapid photography techniques. Independently of those studying birds, those studying fish observe what they call ‘twitch-and-coast’ and ‘burst-and-coast’ types of swimming, allowing significant reductions in energy costs. Hypermilers can take pride in knowing that pulse & glide is truly more natural than the traditional pick-a-speed-and-go technique that most of us were taught and many of us are forced to use when moving in traffic. Our fellow creatures probably evolved their techniques of intermittent locomotion through some form of competitive survival advantage. Perhaps hypermiling will turn out to be the next stage in the evolution of driving?!
GreenJuice, Thanks for your post. A topic worthy of contemplation, consideration, and possible inclusion in the Max FE/MPG bag of tricks. Well done indeed.
As a cyclist, I can tell you that hipermiling techniques are a lot like riding a bike. Trying to expend the least amount of energy to get the job done.
