Development of a CFD method for bicycle design

This thesis details the process undertaken to establish a method of CFD analysis for two-dimensional profiles to establish drag coefficient using SolidWorks Flow Simulation. This research was undertaken in collaboration with Canyon GmbH to be used as a method of analysis for bicycle frame design and analysis with the end goal to improving flow characteristics across a bicycle moving through airflow. Starting using a reference body of known Cd value, a methodology was defined through research to characterize mesh specifications, to create profile specific quantifiable mesh and calculation controls. These studies were namely focused on the determination of the Cd value and further the effective modelling of the expected airflow behaviour for turbulent flows, energy dissipation and frictional forces present. The outcome from this testing was to be able to create a ‘best practice’ for 2D flow simulation for bluff bodies. This ‘best practice’ was then applied to other defined bluff bodies deemed to be similar geometrically to the types of bodies seen in bicycle design. By assessing the ability of SolidWorks Flow Simulation to determine the Cd value for the bluff bodies to an error factor, an analysis was then carried out to provide assess the validity and effectiveness of the methodology. A methodology was determined that was able to produce a valid solution for the preliminary development case, this methodology was then applied to case profile studies to assess the ability of the methodology to fit the scope predetermined; to model and simulate a generic profile effectively with accurate and valid results. The findings of the research concluded that SolidWorks Flow Simulation can be utilised for research and development activities for bicycles, however more work is required to constrain the methodology for more difficult aerodynamic shapes, particularly profiles which show separation before the end of the profile, or boundary layer sensitive cases.