DOI: 10.1615/ICHMT.2014.IntSympConvHeatMassTransf
ISBN Print: 978-1-56700-356-7
ISSN Online: 2642-3499
ISSN Flash Drive: 2642-3502
INFLUENCE OF INTERNAL SWIRL FLOW ON HEAT TRANSFER
SINOPSIS
Maximizing heat transfer is an important task in aerospace engineering applications in order to extend component life-time or to increase efficiency by reducing cooling mass flow. One effective method to cool turbine blades is to provide the blade with internal cavities fed with cooling air. It is a matter of common knowledge that heat transfer can be enhanced by supplying the cooling air with an angular momentum. In this study, Large Eddy Simulations (LES) have been carried out to investigate the flow phenomena in a swirl tube with a ring exit orifice. The velocity field following from the time-averaged LES results is briefly discussed and compared with experimental data acquired by Magnetic Resonance Velocimetry. The LES captures unsteady flow structures close to the inner wall of the swirl tube which are unstable in place and time. In accordance with their length and time scales and the steep velocity gradient in the boundary layer along the concavely curved inner wall of the swirl tube, these structures were identified as Görtler-vortex-like structures. The impact of these vortex structures on heat transfer was analyzed within a further LES. A comparison to the heat transfer of a fully-developed flow proved such a swirl flow as beneficial with respect to cooling issues.