CFD simulations of the flow around a cyclist subjected to crosswinds

Research output: Contribution to journalArticle

Abstract

For the first time, an extensive numerical study of the effect of crosswinds on the flow around a cyclist on a bicycle with stationary wheels has been undertaken for crosswind (yaw) angles ranging from 0° to 90°. The flow field and the aerodynamic forces have been obtained using three numerical techniques: Reynolds Averaged Navier Stokes (RANS), Detached Eddy Simulation (DES) and Large Eddy Simulation (LES). RANS simulations have been undertaken for all the range of yaw angles to provide a general insight of the flow around a cyclist, whilst DES and LES have been undertaken at 15° yaw angle in order to investigate the time-varying flow physics in detail. The aerodynamic forces have been compared with a series of wind tunnel experiments. The RANS results showed the development of large flow separation around the bicycle with increasing yaw angles. The instantaneous flow structures and the auto-spectral densities of the time histories of the force coefficients are identified and revealed that the DES and LES turbulence models are able to predict the dominant frequencies found in the physical experiments. This work provides an improved understanding of the flow characteristics around a cyclist in crosswinds that will hopefully help to improve the safety of cyclists.

Details

Original languageEnglish
Pages (from-to)31-41
Number of pages11
JournalJournal of Wind Engineering and Industrial Aerodynamics
Volume144
Early online date18 Aug 2015
Publication statusPublished - 1 Sep 2015
Event6th International Symposium on Computational Wind Engineering - Hamburg, Germany
Duration: 8 Jun 201412 Jun 2014

Keywords

  • Crosswinds, cyclists, Aerodynamics, Turbulence modeling , CFD modelling