BEIJING TSINGHUA UNIVERSITY
Beijing Tsinghua University – Internal Passage Heat Transfer Augmentation Methods and Associated Unsteady Flow Structural Characteristics
This research activity is a collaborative effort between Dr. Ligrani and Professor Jing Ren and Professor Hongde Jiang, and associated graduate students, of the Institute for Gas Turbines of Beijing Tsinghua University of the P. R. China. Of interest is experimental and numerical investigation of unsteady impingement cooling within a blade leading edge passage 1, as well as unsteady structure and development of both laminar and turbulent impingement jets, including Kelvin-Helmholtz vortex development 2-3. Different turbulence models are also assessed in regard to predictions of narrow passage flows with impingement jets 4, and with pin fin arrays 5. Other recent efforts address effects of Reynolds number, hole spacing, jet-to-target distance, and hole inclination angle on the convective heat transfer performance of an impinging jet array over Reynolds numbers from 5,000 to 25,000 6. Streamwise and spanwise jet-to-jet spacing 4D-8D and jet-to-target plate distance of 0.75D to 3D are employed, where D is impingement hole diameter. Also investigated is the effect on the heat transfer coefficient of hole inclination angle θ, which ranges from 0° to 40°. More recent research efforts address the influences of arrays of surface micro pin-fins on jet array impingement heat transfer. In this investigation, considered are the effects of jet to target plate distance, micro pin-fin shape, micro pin-fin height, and Reynolds number7.
REFERENCES
1 Experimental and Numerical Investigation of Unsteady Impingement Cooling Within a Blade Leading Edge Passage (L. Yang, J. Ren, H. Jiang, and P. M. Ligrani), International Journal of Heat and Mass Transfer, Vol. 71, pp. 57-68, April 2014.
2 Unsteady Structure and Development of a Row of Impingement Jets, Including Kelvin-Helmholtz Vortex Development (L. Yang, P. M. Ligrani, J. Ren, and H. Jiang), ASME Transactions-Journal of Fluids Engineering, Vol. 137, No. 5, pp. 051201-1 to 051201-12, May 2015.
3 Unsteady Heat Transfer and Flow Structure of a Row of Laminar Impingement Jets, Including Vortex Development (L. Yang, Y. Li, P. M. Ligrani, J. Ren, and H. Jiang), International Journal of Heat and Mass Transfer, Vol. 88, pp. 149-164, September 2015.
4 Assessment of Six Turbulence Models For Modelling and Predicting Narrow Passage Flows, Part 1: Impingement Jets, (W. Li, J. Ren, H. Jiang, and P. M. Ligrani), Numerical Heat Transfer, Part A: Applications, Vol. 69, No. 2, pp. 109-127, January 2016.
5 Assessment of Six Turbulence Models For Modelling and Predicting Narrow Passage Flows, Part 2: Pin Fin Arrays, (W. Li, J. Ren, H. Jiang, Y. Luan, and P. M. Ligrani), Numerical Heat Transfer, Part A: Applications, Vol. 69, No. 5, pp. 445-463, March 2016.
6 Effect of Reynolds Number, Hole Patterns, and Hole Inclination on Cooling Performance of an Impinging Jet Array – Part 1: Convective Heat Transfer Results and Optimization (W. Li, X. Li, L. Yang, J. Ren, H. Jiang, and P. M. Ligrani), ASME Transactions-Journal of Turbomachinery, Vol. 139, No. 4, pp. 041002-01 to 041002-11, April 2017.
7 Flow and Heat Transfer Characteristics of Micro Pin-Fins Under Jet Impingement Arrays (X. Lu, W. Li, X. Li, J. Ren, H. Jiang, and P. M. Ligrani), International Journal of Heat and Mass Transfer, Volume 143, Paper No. 118416, pp. 1-14, November 2019.