Thermal fluctuations in turbulent flow

Conjugate heat transfer in single and two phase fluid flow are widely encountered in day to day life and have great industrial importance too. In conjugate heat transfer, temperature fluctuations of fluid adjacent to a solid wall plays important role in system design and safety. In the view of this, a new experimental facility has been designed and installed in the THELMA laboratory. The aim of the present study is to investigate temperature fluctuations on a heated foil, which is cooled with adjacent turbulent flow in square duct channel. The figure shows an image of the heated foil in optical and IR light taken with the fast-speed cameras. An interesting pattern is observed at the surface of the heated foil. In single phase flow, the so-called thermal streaks are observed, which are footprints of the coherent structures transported in the turbulent flow. Similarly, an even more distinct footprint of the bubbles is observed at the heated foil cooled by the two phase flow.

Publications:

• I. Tiselj, M. P. Sharma, B. Zajec, N. Veljanovski, J. Kren, L. Cizelj and B. Mikuž “Investigation of turbulent flow in square duct with heated foil thermometry,” International Journal of Heat and Mass Transfer 175, 121381, Elsevier BV (2021); doi: https://doi.org/10.1016/j.ijheatmasstransfer.2021.121381.
• J. Kren, B. Mikuž and I. Tiselj “Numerical analysis of turbulent heat transfer in rectangular duct,” ICHMT International Symposium on Advances in Computational Heat Transfer, CHT-21-191, Rio de Janeiro, Brazil, 2021 August 15-19. Conference proceedings.
• J. Kren, B. Mikuž, and I. Tiselj, “Large Eddy Simulation Of Turbulent Flow With Different Prandtl Numbers Near Uniformly Heated Wall,” 29th International Conference Nuclear Energy for New Europe, Portorož, Slovenia, 2020 September 7-10. Conference proceedings.
• M. P. Sharma, B. Mikuž, I. Tiselj, B. Zajec, N. Veljanovski, J. Kren, and L. Cizelj, “Investigation of Temperature Fluctuation in Conjugate Heat Transfer,” 29th International Conference Nuclear Energy for New Europe, Portorož, Slovenia, 2020 September 7-10. Conference proceedings.

Page editor: Anil Kumar Basavaraj