The pipeline transportation of coal slurries is always subject to a temperature difference between the outdoors environment and the fluid body. As slurries’ viscosity is typically temperature dependent, the flow is accompanied by the heat transfer. In this study, we used the CFD method to investigate temperature distributions and flow structures in straight and curved channels, which has not previously been investigated, according to our knowledge. First, the results demonstrate that the cooling process influences the flow structures along the stream. The fluid turns more sharply in the cooler fluid in the curved channel, the streamlines overlap at an earlier position within the bend, and the velocity maximum zone is wider. Cooling also has a significant impact on transverse flow. Because of the higher viscosity of the more cooled fluid and thus the difficulty of shearing the fluid in the stream-wise direction, the vorticity and strength of the vortex flow are greater. The fluid velocity at the central part of the channel points toward the inner wall at the beginning of the bend, resulting in an inner-wall biased temperature distribution, as the heat transfer is partially carried out by the fluid velocity. The central velocity points toward the outer wall at the end of the bend, resulting in the outer-wall biased temperature profile.

Micro-particle manipulation, based solely on the Dean drag force, has begun to be advocated for with the goal of lowering the pumping pressure and simplifying the complexity of the coupling effects of the inertial lift force and the Dean drag force, thus reducing the difficulty of theoretically predicting particle motion. We employed the CFD-DEM two-way coupling method in this work to quantitatively study the lateral (z in axis) motion of particles (7–10 $\mathsf{\mu }\mathrm{m}$), in square or half-circle segment serpentine microchannels, that was only reliant on Dean drag with the blockage ratio $\frac{d}{D_h}=$ 0.04 (the inertial lift effects show at $\frac{d}{D_h}>0.07$). In the square-segment serpentine channel, under the conditions of single-side-wall sheath flow and sedimentation, we discovered that the particles exhibit a twist-type lateral trajectory around each turn, with the larger particles always twisting in the opposite direction of the smaller particles, as a result of the four-grid-pattern distribution of the lateral velocity values at each turn. The large and small particles are separated at the channel’s exit at $Re$ = 56.7, De = 17.8, indicating the likelihood of separation only due to the Dean drag. This separation efficiency decreases as $Re$ and De decreases. The lateral position and velocity values of the particles oscillate, as time passes, due to the twist trajectory, with the oscillation amplitude increasing as $Re$ or De decreases and deflecting toward the inner side of z. In the cases of the two-side-wall-symmetric sheath flow, the particles exhibit only a little lateral deflection, and particle separation is not achieved. The deflection of the oscillation is uncertain and does not change regularly with any physical quantity.