Effect of radial injection on heat transfer of a Taylor–Couette–Poiseuille flow

Abstract

The effect of radial flow injection on the heat transfer characteristics of a Taylor–Couette–Poiseuille flow in an annulus is numerically investigated using the SST k-ω turbulence model. The ranges of the axial Reynolds number (Re_A) and the rotational Reynolds number (Re_Ω) are $6.58\times {10}^4-1.37\times {10}^5$ and $7.19\times {10}^4–1.8\times {10}^5,$ respectively. For every combination of axial and rotational Reynolds number, flow is injected radially into the air gap through a rectangular duct located on the inner cylinder with the injection rate ${\dot{m}}_{inj}/{\dot{m}}_{axial}$ which varies from 0.02 to 0.14. Airflow in the air gap, before the injection, is in a fully developed condition and the effect of radial injection on the heat transfer of inner and outer cylinder is investigated in terms of the Nusselt number. In the studied range, radial injection increases the averaged Nusselt number up to 24% on the inner cylinder and up to 27% on the outer cylinder. In order to compare the heat transfer increase due to the radial injection, Nu* is defined as the difference between local Nusselt and Nusselt number of the fully developed flow happening at the same configuration without injection, and it is shown that though the trend of local Nusselt on the inner and outer cylinder is different, the averaged Nu* on both surfaces follows the same trend.

Additional information

Funding

The authors would like to acknowledge the funding for this project from the Iran National Science Foundation (INSF).