Print Email Facebook Twitter Interphasial energy transfer and particle dissipation in particle-laden wall turbulence Title Interphasial energy transfer and particle dissipation in particle-laden wall turbulence Author Zhao, L. Andersson, H.I. Gillissen, J.J.J. Faculty Applied Sciences Department Chemical Engineering Date 2013-01-09 Abstract Transfer of mechanical energy between solid spherical particles and a Newtonian carrier fluid has been explored in two-way coupled direct numerical simulations of turbulent channel flow. The inertial particles have been treated as individual point particles in a Lagrangian framework and their feedback on the fluid phase has been incorporated in the Navier–Stokes equations. At sufficiently large particle response times the Reynolds shear stress and the turbulence intensities in the spanwise and wall-normal directions were attenuated whereas the velocity fluctuations were augmented in the streamwise direction. The physical mechanisms involved in the particle–fluid interactions were analysed in detail, and it was observed that the fluid transferred energy to the particles in the core region of the channel whereas the fluid received kinetic energy from the particles in the wall region. A local imbalance in the work performed by the particles on the fluid and the work exerted by the fluid on the particles was observed. This imbalance gave rise to a particleinduced energy dissipation which represents a loss of mechanical energy from the fluid–particle suspension. An independent examination of the work associated with the different directional components of the Stokes force revealed that the dominating energy transfer was associated with the streamwise component. Both the mean and fluctuating parts of the Stokes force promoted streamwise fluctuations in the near-wall region. The kinetic energy associated with the cross-sectional velocity components was damped due to work done by the particles, and the energy was dissipated rather than recovered as particle kinetic energy. Componentwise scatter plots of the instantaneous velocity versus the instantaneous slip-velocity provided further insight into the energy transfer mechanisms, and the observed modulations of the flow field could thereby be explained. Subject multiphase and particle-laden flowsturbulence simulation To reference this document use: http://resolver.tudelft.nl/uuid:326a44e0-1e70-45df-9d18-b26dacbfd05a DOI https://doi.org/10.1017/jfm.2012.492 Publisher Cambridge University Press Embargo date 2014-01-09 ISSN 1469-7645 Source http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8807382&fulltextType=RA&fileId=S0022112012004922 Source Journal of Fluid Mechanics, 715 (2013) Part of collection Institutional Repository Document type journal article Rights (c) 2013 Cambridge University Press Files PDF Zhao.pdf 2.5 MB Close viewer /islandora/object/uuid:326a44e0-1e70-45df-9d18-b26dacbfd05a/datastream/OBJ/view