Numerical investigation of flow and heat transfer between concentric cylinders with slit wall

This paper investigates the flow field distribution and heat transfer characteristics of turbulent flow between concentric cylinders with slit wall in the outer cylinder. The slit wall cross sections are triangle, rectangle and trapezoid respectively. The governing equations are established by the PANS model which is modified from the standard k - epsilon model. The rotating Reynolds number ranges from 2336 to 4682 and axial Reynolds number ranges from 161 to 645, the influence of slit wall cross section on the formation and intensity of small vortex in slit region is analyzed. The results show that the slit wall geometry has a significant influence on the flow field distribution and its heat transfer process, the main vortex in annular region and small scale vortex in slit region has a tendency to merge together in the model with trapezoid cross section, resulting in more intense mixing of fluid with different temperature, therefore, the slit model with trapezoid cross section shows the best heat transfer performance among three models. The present analysis results may be applied for the structural design and optimization of many related rotating machinery.