|Principal Investigator(s)||J.G.M. Kuerten|
In many examples in industry and the environment particles are transported in a turbulent flow. A well-known example is dispersion of pollution in the atmosphere or in a river. Particle motion is influenced by all scales of motion of the turbulent flow. Due to the enormous computational requirements calculation of particle dispersion by solving the complete flow field by means of direct numerical simulation (DNS) is only possible at relatively low Reynolds numbers. For larger Reynolds numbers a statistical description of the particle behaviour might offer a solution. Recently, such a method has been proposed based on a stochastic Langevin equation for particle velocity. In order to determine the coefficients in this model Lagrangian velocity correlation functions are required. The aim of this proposal is the determination of these velocity correlation functions at intermediate values of the Reynolds number by means of DNS and passive particle tracking in turbulent channel flow. In this way, the recently developed model can be validated and tested and an efficient model for the calculation of particle dispersion in turbulent flow at large Reynolds number has been obtained.