b'Sport Science | Engineer InnovationImage credit: Creative Commons Attribution- Figure 1: Breaking 2 simulation scenariosShare Alike 4.0 InternationalNike Breaking 2: 2:00:23 surrounded by a team of athletes in delta Before the run, much of the publicity hadformation.focused on Nikes spring-loaded Vaporfly Elite running shoe [2], which they hadThe simulations comprise four million claimed improves running efficiency bycomputational cells for the solo runner, as much as 4 percent. However, in the8.5 million for the pack formation, 22.5 days afterward, much of themillion for the car and virtual Kipchoge conversation turned to aerodynamics,and 24 million for the rest, and in the and the influence of the unfeasibly largewake of, the car and runners. The kw-SST timing board that was mounted on topturbulence model was used (for those of of the pace car that drove in front ofyou wondering) and we also verified the Kipchoge, and the delta formationsimulations using a k- Realizable model, adopted by his team of relaying pacers.which was within 2 percent agreement By some calculations [3], drafting wasfor the baseline and final cases; responsible for about 1 minute and 30y+ was <20. For simplification, each of seconds of the 2 minutes and 32 secondsthe runners is assumed to be a static that Kipchoge knocked off Kimettosmannequin frozen in a single running world record. pose (we do not model the running movement of the arms and legs, We ran four simulations: although we have previously The first case is a worst-case scenario -demonstrated that the average drag on a an undrafted solo runner - while thepedaling cyclist is well predicted using a fourth case simulates the actualstatic model).conditions of the Breaking 2 attempt, in which our virtual Kipchoge is followingThe plots in figure 2 show the velocity the pace car (and timing board) whilstfield around our virtual Kipchoge in each Baseline Car OnlyPacers only Pacers + CarVelocity (kph)08 16243240Figure 2: Velocity field around virtual Kipchoge in each of the four scenarios11'