Discrete Transport from a Tumbling Prolate Spheroid in a Simple Shear Flow

Through high-fidelity numerical simulation based on a multi-grid strategy with the lattice Boltzmann framework, an in-depth study on the heat and mass transport from a prolate spheroid suspended in a simple shear flow has been carried out. In the simulation, the temperature and mass concentration are modeled as a passive scalar released at the spheroid's surface. The interaction between the carrier fluid and the suspended spheroid, as well as the resultant scalar transport process, have been investigated. The interaction creates several flow modes in the fluid layer surrounding the spheroid. When the advective scalar transport is weak, the passive scalar released at the spheroid surface is transported through the fluid layer to the outer passing fluid via diffusion, and then is transported downstream by the passing fluid via flow advection. When the advective scalar transport is strong, most of the passive scalar is gained by the fluid layer surrounding the spheroid. The multiple flow modes of the fluid layer and the outer passing fluid lead to multiple advective scalar transport modes, constituting a spatiotemporally discrete set of scalar transport mechanisms for the prolate spheroid in a simple shear flow. Factors such as spheroid-to-fluid density ratio, spheroid aspect ratio, and Reynolds number, affect the behaviors of the fluid and spheroid, thus have influences on the scalar transport.