In order to provide further insight into multiple-hole film cooling of gas turbine blades, large-eddy simulations (LES) was performed for stationary and rotating discrete fluid effusion through periodic inclined cylindrical holes in a flat wall separating two turbulent streams. This generic configuration, investigated earlier using LES by Mendez and Nicoud (2008), was chosen to further study effects of using different computational domains, the corresponding bi-periodic boundary conditions, mesh types and quality, and the influence of rotation. The preliminary simulations in a diamond-shaped domain with a single hole, and a rectangular domain containing two holes, reproduced well the main flow features detected by Mendez and Nicoud (2008). The imposed system rotation - mimicking the real turbo-machinery operation - caused notable alteration of the effusion jet direction and modification of the vortical structures and their wall imprints with consequent effects on the local and average wall friction, expected also to modify the wall heat transfer. Copyright © 2009 Local Organising Committee.
Large Eddy Simulation of Periodic Discrete Hole Effusion without and with Rotation / N., Liu; Borello, Domenico; K., Hanjalic; Z., Tao. - STAMPA. - (2009), pp. 109-118. (Intervento presentato al convegno 8th European Conference on Turbomachinery tenutosi a Graz; Austria nel 23-27 March 2009).
Large Eddy Simulation of Periodic Discrete Hole Effusion without and with Rotation
BORELLO, Domenico;
2009
Abstract
In order to provide further insight into multiple-hole film cooling of gas turbine blades, large-eddy simulations (LES) was performed for stationary and rotating discrete fluid effusion through periodic inclined cylindrical holes in a flat wall separating two turbulent streams. This generic configuration, investigated earlier using LES by Mendez and Nicoud (2008), was chosen to further study effects of using different computational domains, the corresponding bi-periodic boundary conditions, mesh types and quality, and the influence of rotation. The preliminary simulations in a diamond-shaped domain with a single hole, and a rectangular domain containing two holes, reproduced well the main flow features detected by Mendez and Nicoud (2008). The imposed system rotation - mimicking the real turbo-machinery operation - caused notable alteration of the effusion jet direction and modification of the vortical structures and their wall imprints with consequent effects on the local and average wall friction, expected also to modify the wall heat transfer. Copyright © 2009 Local Organising Committee.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
