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Rough CFD Simulation

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Rough CFD Simulation

by: BTR Forum Member: zebragonzo

This model is intended to show the flow of air around a rider and to give armchair aerodynamicists a chance to better understand how air flows.

Because of the complexity of the model and the limited time available to run it, the mesh has had to be simplified such that the accuracy isn't spot on. Additionally, the legs and wheels are not rotating. Finally, there are some areas that did not mesh quite correctly (front of the chainring, some of the rear wheel, top of the down tube). Despite these errors the simulation reports a drag of 2480g for both the rider and bike which is as would be expected for a cyclist in this position thus indicating that the error isn't sufficiently high that the model does not resemble real life.

Last Updated on Sunday, 14 March 2010 21:10

Big Fat Helmet

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Big Fat Helmet™

Can someone please tell Robbie McEwen to retire the Big Fat Helmet™ that he and his teammates wore during the opening Tour de France prologue?  It is physically painful for me to look at that thing.  Not only is his helmet just plain dorky looking, there isn’t a doubt in my mind that it is an extremely slow helmet and ultimately is a detriment to his time-trial performance.  What would make me say such a thing? 

Last Updated on Sunday, 24 January 2010 04:53

Frontal Area: KW Position

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Last weekend I was fiddling with my frontal area measurement setup and also working on my position a bit.  I was able to verify again, that I am able to reduce the data pretty consistently - on the order of 1% variation using the same photo.  I also found out that it is best to take the pictures without a flash, since the background will show a shadow and increase frontal area by 25% or so (the previous setups were done outside while this time I was in my garage). 

Last Updated on Sunday, 24 January 2010 05:25

Skinsuits and Boundary Layers

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What do Skinsuits have to do with Boundary Layers?

1  Prologue – The Tour

A week ago Saturday, I sat in front of the TV for a solid two plus hours.  I had been looking forward to this self-indulgent, yet taken for granted, treat for nearly a year.  It wasn’t so long ago that all of us had to wait a week to get any coverage of the Tour de France – even then, it was watered down and tainted with John Tesh-ian keyboard rhythms and Phil Ligget trying really hard to be a wordsmith, rather than a spirited bike race announcer.  Who could forget the ‘87 Tour coverage of the Ventoux TT stage – “How far… How high… How fast…”  The images of Jean-Francois Bernard suffering up that climb with Phil doing the voiceover haunt me to this day.


Last Updated on Tuesday, 23 February 2010 04:54