Flow past a sphere up to a Reynolds number of 300

摘要: The flow of an incompressible viscous fluid past a sphere is investigated numerically and experimentally over regimes including steady unsteady laminar at Reynolds numbers up to 300. Flow-visualization experiments are used validate the numerical results provide additional insight into behaviour flow. Near-wake visualizations presented for both flows. Calculations 200 show axisymmetric compare well with previous experimental observations. For 210 270, non-axisymmetric regime found, also in agreement work. To advance basic understanding this transition, symmetry breaking mechanism proposed based on detailed analysis calculated field.Unsteady greater than 270. number 300 highly organized periodic dominated by vortex shedding. An vortical structure wake reveals sequence shed hairpin vortices combination previously unidentified induced vortices. favourably which, interestingly, fail reveal Based deduced symmetry-breaking mechanism, kinematics, results, driving transition proposed.