Three-dimensional flow and heat transfer calculations of film cooling at the leading edge of a symmetrical turbine blade model

Film cooling of a symmetrical turbine-blade model by lateral and non-latera l injection from one row of holes placed on each side near the leading edge is calculated with a 3D finite-volume method on multi-block grids. For var ious blowing rates, the flow and temperature fields are predicted, and in p articular the contours of him-cooling effectiveness on the blade surface, w hich are compared with measurements. Various versions of the k-epsilon turb ulence model are employed: the standard model with wall functions (WF), a t wo-layer version resolving the viscous sublayer with a one-equation model a nd an anisotropy correction due to Bergeles et al. [Num. Heat Transfer 1 (1 978) 217-242] which acts to promote the lateral turbulent exchange. The ori ginal Bergeles proposal is modified for application in the viscous sublayer . With the standard model, the lateral spreading of the temperature field i s underpredicted, leading to averaged film-cooling effectiveness values tha t are too low. The situation is improved by using the Bergeles correction, especially when the modified correction is applied with the two-layer model (TLK). This yields effectiveness contours in reasonably good agreement wit h the measurements, but the laterally averaged effectiveness is not predict ed in all cases with good accurary. However, the trend of the various influ ence parameters is reproduced correctly. (C) 2001 Elsevier Science Inc. All rights reserved.