Racing Bike
From the frames to the helmets to the tires to the wheels, the bike’s design plays an important role in helping the amateurial, professional cyclists and triathletes to compete successfully. Similarly the aerospace and automotive industries, manufacturers work hard to reduce the weight and the drag of bikes. They may construct frames of lightweight material, such as carbon fiber composites. They may reshape the wheel rims or even reduce the number of spokes in the wheels. They may also tweak the tires’ thickness and tread to reduce rolling resistance on the road.
However, to isolate and evaluate the impact of hundreds of design variables, wind tunnel testing is cost-prohibitive. Computational fluid dynamics results compare favorably to experimental results obtained from wind tunnel tests. Recently, repeatable workflow methodology has been developed to radically accelerate the entire CFD process and optimization technics according to predefined variables are henceforth possible.
CFD simulations around a racing bike frame have been computed. The free stream velocity is aligned with the bike geometry. So for this particular case there is no side wind effects. Following 2 pictures present the velocity and pressure fields on the symmetry plane. Hovering over the picture shows the overlaid grid. The snappyHexMesh utility was used. One can easily notice that many levels of refinement around the frame were set-up.
On the left hand side, pictures show details of the surface mesh obtained with the snappyHexMesh utility after the snapping-to-surfaces stage. Hovering over the middle thumbnail will enlarge the picture. Improvements can still be made to accurately capture the sharp feature edges.
Aerodynamic forces and moments help designers to improve stability and maneuverability aspects as well. The study of the air flow around a rotating bicycle wheel in contact with the ground is becoming also of great interest. This gallery shows additional pictures of the pressure contours on the racing bike frame.
