AERO SPEED GEL MEASUREMENTS
All aerodynamic drag testing was done in the state-of-the-art low speed wind tunnel testing facility at Bike Valley. Initial testing of the first prototypes was done on a cylinder wrapped with pig-skin. Second phase of testing was done on real cyclists.
MEASUREMENT PHASE 1
To test a reference object that simulates a leg or arm of a cyclist, a cylinder was chosen with a diameter of 100mm. This cylinder was wrapped with the skin of a pig, because this closely resembles human skin. The goal of this test protocol was to optimize the carrier liquid and vortex genertor inside the liquid
Figure 3 wrapped cylinder setup in wind tunnel
To see the effect of the air speed on the turbulence, it was chosen to test at four different air velocities, all correlated to relevant cycling speeds. Chosen wind tunnel air velocities: 10.4, 11.8, 13.3, 14.8 m/s. This corresponds with cycling speeds of 37.5, 42.5, 47.9 and 53.3 km/h. Measured drag force on the cylinder were converted to watt for easier comparison.
Figure 4 measured drag (in watt). Light blue gives baseline drag without NAQI aero speed gel. Other colors are the results different prototypes with changing vortex generators inside the gel.
Each measurement was repeated four times. Twice with a measurement time of 30 seconds, and twice with a measurement time of 60 seconds. This was done to check the repeatability of the test setup. The difference between the four measurements was always below 0.1N, which proves that the repeatability was excellent.
MEASUREMENT PHASE 2
Second phase of testing was with real cyclists. It was chosen to test with a cyclist in TT position and clothing, with standard clothing a position for normal road cycling and with a triathlon suite on a triathlon bike. 5 athletes were used as test subjects. It was also chosen to test the gel on both the arms and the legs, depending on the specific clothing and discipline (TT, road, triathlon). For this testing phase it was chosen to only test at one air speed. The choses airspeed chosen to be relevant for the specific discipline. The chosen air speed was 13.9 m/s or 50.0 km/h for TT position, 12.4m/s or 44.64 km/h for standard cycling position and 10.9m/s or 39.2 km/h for triathlon.
Figure 5 contour tracking to ensure exactly the same position is taken for every measurement
Because the position of the cyclist with different gels and without the gel has to be exactly the same, the repeatability was also checked by doing every measurement twice. Within a range of about 1.5 watt, the results correlated well. The position of the cyclist was checked and adjusted for every measurement to be exactly the same, by plotting the contours of the position of the reference measurements in front of the cyclist. This way he/she could check and adjust his/her position to exactly math that of the reference.
Figure 6 Cyclist in TT position in the wind tunnel
In TT position the average drag was 374.5 Watt, without NAQI aero speed gel and with gel, the drag was 360.5 Watt. This gives a difference of 14 Watt at the chosen speed. Which corresponds with a reduction in drag close to 4%. The gain in time on a 9 km TT using this NAQI Aero Speed Gel is 8.4 seconds or 46.6 seconds on a 50 km TT. Thus close to 1 second per km. This result was obtained by only applying NAQI Aero Speed Gel to the legs of the cyclist.
Figure 7 triathlete in wind tunnel testing NAQI aero speed gel on legs.