Aerodynamics and heat transfer in a narrowing annular channel with a swirling flow and a different taper of inner surface

The aerodynamics and heat transfer of a turbulent swirling flow in a narrowing annular channel along the length are numerically studied using CFD methods using the ANSYS Fluent package. Modeling was performed when the Reynolds number Rein changed from 11.3·103 to 77.1·103. The annular channel narrowing was carried out by increasing cone angle of the inner surface from 0о to 1.9о. As a result of the investigation, it was revealed that due to the narrowing of the output section, the total velocity in the annular channel increases. In this case, a decrease in swirl flow intensity along the length is due to a decrease in tangential velocity and a simultaneous increase in the axial velocity. With a decrease in the ratio of cross-sectional areas at channels exit fchout and entrance fchin at a constant value of Rein, total resistance coefficient of the device increases. This is due to an increase of the resistance coefficient in the channel and at its exit. With a decrease in Rein and fchout/fchin>0.4 the total resistance coefficients of the device decrease due to a drop in the swirl flow. And at fchout/fchin