Analysis Of The Affect Of Particle Rotation On Turbulent Modulation

In the fields of multi-phase,the turbulence modulation of gas phase affected by particle phase is a national major interest. Nowadays, although some empirical or semi-empirical turbulence modulation models have been proposed, their accuracy still needs to be increased. The key point is the regular pattern of the turbulence modulation enhanced by the wake effect of rotating particle. Especially, the rotating effect of particle on turbulence modulation, which is unneglectable, does not take into account until now.In this work, the simulation of gas turbulence flow pass the sphere is made by Realize k -ε turbulence model with un-structure meshes.First of all, by changing the Reynolds number of particles and particle rotation speed coefficient, the fluctuation rules of gas turbulence caused by the single particle rotation effect: the Modulation turbulence of particles in the wake is weaken with the effect of particle rotation, the greater particle rotation speed coefficient, the bigger the particles to wake the turbulence effect,and then the wake vortex area turbulent kinetic energy is smaller, as a result the smaller turbulent modulation of gas accordingly. At last, rotation turbulent modulation function of a single particle is established that:On this basis, the turbulence fluctuation rules of tandem double particles of by the effect of particles rotation is analyzed, the calculation results show that:(1) when the particle spacing is smaller, particle rotation effect of particle 2 have a greater influence on the turbulent fluctuation of particle 1. As the particle 2 rotation speed coefficient increases, the turbulent fluctuation particle 2 decreases for particle 2 reverse rotation;On the contrary, as the particle rotation speed coefficient increases, the turbulent fluctuation of particle 2 have a slightly increased firstly, and then gradually decreased;When the particle spacing between particle 1 and particle 2 increases to a certain degree, the turbulent fluctuation of particle 1 caused by the rotation effect of particle2 is abate, the turbulent fluctuation of particle 1 can be ignored;(2) The rotation of particles 1 had a greater influence on the turbulent changes itself, with the increase of particle 1 rotation speed coefficient, turbulent changes of 1 particle gradually decreases, and maximum relative reduction is about 20%;(3) Turbulent changes of particle 1 is increases gradually linearly from reverse rotation to the synthetic rotation. The greater rotation speed coefficient of the particle 1, the greater turbulent fluctuation of the particle 1 caused by the effect of particle 2;(4) Considering the particle spacing and particle rotation effect of tandem double particles, turbulent fluctuation of particles 1can meet the relation as following:...