Evaluation of Wall Heat Transfer in Blade Trailing-Edge Cooling Passage

Abstract:

Model configurations of turbine blade trailing-edge internal cooling passage with staggered elliptic pin-fins in streamwise and spanwise are adopted for numerical investigation using computational fluid dynamics (CFD). Grid refinement study is performed at first to identify a baseline mesh, followed by validation study of passage total pressure loss, which gives 2% and 4% discrepancies respectively for two chosen configurations in comparison with experimental measurements. Further investigations are focused on evaluation of wall heat transfer coefficient (HTC) of both pin-fin and end walls, and it is found that CFD predicted pin-fin wall HTC are generally in good agreement with test data for the streamwise staggered elliptic pin-fins, but not the spanwise staggered elliptic pin-fins in which some discrepancies occur. CFD predicted end wall HTC have shown reasonable good agreement for the first three rows, but discrepancies seen in downstream rows are around a factor of 2-3. A ratio of averaged pin-fin and end walls HTC is estimated 1.3-1.5, close to that from a circular pin-fin configuration that has 1.8-2.1. Further study should focus on improving end wall HTC predictions, probably through a conjugate heat transfer model.

• Periodical: Applied Mechanics and Materials (Volumes 284-287)
• Pages: 738-742
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.284-287.738
• Online since: January 2013
• Authors: Yu Feng Yao, Marwan Effendy, Jun Yao
• Keywords: CFD Modelling, Heat Transfer Evaluation, Turbine Blade Cooling Effectiveness

References

[1] J.C. Han, A.P. Rallabandi, Frontier in Heat and Mass Transfer, 1, 013001 (2010) 1-21.

[2] J. Bredberg, PhD Thesis Chalmer University, Dept of Thermo and Fluid Dynamics, (2002).

[3] J.C. Han, International Journal of Rotating Machinery, 10(6) (2004) 443-457.

[4] L. Tarchi, B. Facchini, S. Zecchi, International Journal of Rotating Machinery, (2008) 1-11.

[5] C. Carcasci, F. Simonetti, Int. Symp. on Heat Transfer in Gas Turbine Systems, (2009).

[6] B. Facchini, F. Simonetti, L. Tarchi, ASME Paper GT-59925 (2009).

[7] C. Bianchini, B. Facchini, F. Simonetti, L. Tarchi, S. Zecchi, ASME GT-23536 (2010).

[8] G. Liang, US Patent No. 7, 780 (2010) 414 B1.

[9] B. Facchini, L. Innocenti, L. Tarchi, ASME GT-53152 (2004).

[10] B. Facchini, L. Tarchi, ASME GT-51047 (2008).

[11] J. Choi, PhD Dissertation Texas A & M University, Mechanical Engineering, (2004).

[12] D.E. Metzger, R.A. Berry, J.P. Bronson, J. of Heat Transfer, 104(4) (2008) 700-706.