THERMO-HYDRAULIC CHARACTERISTICS OF ADDITIVELY MANUFACTURED MINI-CHANNELS
Abstract
The aim of this work is to analyze the heat transfer, hydraulic resistance and thermo-hydraulic performance of a new type of heat exchange channels made by additive technology. The main factors affecting the quality of products and determining the heat transfer and hydraulic resistance of the channels are noted. Well-known ratios for calculating hydraulic resistance and heat transfer are not suitable for such high roughness. Data on the AT resistance coefficient of the channels show that even at low Reynolds numbers there is a contribution of roughness. With increasing roughness, the intensification of resistance and heat exchange increases. The transition occurs at 700 < Re < 2000. Comparison of data on heat transfer augmentation and increase of hydraulic losses, as well as their thermo-hydraulic characteristics has been carried out. The hydraulic resistance coefficient of AT channels is significantly higher than the resistance coefficient of smooth channels. Heat transfer augmentation in wave-shaped channels is 2 times higher than augmentation in straight channels. Channels with pin fins allow to achieve a very high heat transfer augmentation (up to 8). Channels with internal grids provide high intensification, but have the highest hydraulic losses. The dependence of the Reynolds analogy factor on the resistance increase factor showed that the straight channels of all geometric forms fit on one dependence closed to the lower boundary line, and have a low hydraulic resistance. Data on channels with pin fins have a large spread. A number of points are above the upper boundary line, which refers to channels with low surface roughness.
References
2. Kirsch, K. L., and Thole, K. A. (2017) Pressure Loss and Heat Transfer for additively and conventionally manufactured pin fin arrays. Int. J. Heat Mass Transfer, 108 (Pt. B), p. 2502–2513.
http://dx.doi.org/10.1016/j.ijheatmasstransfer.2017.01.095
3. Stimpson C.K., Snyder J.C., Thole K.A., Mongillo D. (2018) Effectiveness measurements of additively manufactured film cooling holes, J. Turbomach. 140 (1) 1–11. 011009. https://doi.org/10.1115/1.4038182
4. Wildgoose, A. J., Thole K.A., Sanders P. L., Wang L. Impact of additive manufacturing on internal cooling channels with varying diameters and build directions, J. Turbomach. 143 (7) (2021) 1–11. 071003. https://doi.org/10.1115/1.4050336
5. Parbat S.N., L. Yang L., Min, Z., M.K. Chyu M.K. (2019) Experimental and numerical analysis of additively manufactured coupons with parallel channels and inline wall jets, J. Turbomach. 141 (6) 1–10. 061004. https://doi.org/10.1115/1.4041821
6. Collins I.L., Weibel J.A., Pan L., Garimella S.V. Experimental characterization of a microchannel heat sink made by additive manufacturing, in: Proceedings of the 17th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems, ITherm 2018, Institute of Electrical and Electronics Engineers Inc., 2018, pp. 171–177. Doi:10.1109/ITHERM.2018.8419588
7. Stimpson C.K., Snyder J.C., Thole K.A., Mongillo D. (2016) Roughness effects on flow and eat transfer for additively manufactured channels, J. Turbomach. 138 (5) (2016) 051008. DOI:10.1115/1.4032167
8. Snyder J.C., Stimpson C.K., Thole K.A, Mongillo D. (2016) Build direction effects on additively manufactured channels, J. Turbomach. 138 (5) 051006. https://doi.org/10.1115/1.4032168
9. Stimpson C.K., Snyder J.C., Thole K.A., Mongillo D. (2017) Scaling roughness effects on pressure loss and heat transfer of additively manufactured channels, J. Turbomach. 139 (2) 021003. https://doi.org/10.1115/1.4034555
10. Wildgoose A.J., Thole K. Heat transfer and pressure loss of additively manufactured internal cooling channels with various shapes (2022) ASME Paper GT2022-82298 https://doi.org/10.1115/1.4056775
11. Kirsch K.L., Thole K.A. (2016) Heat transfer and pressure loss measurements in additively manufactured wavy microchannels, J. Turbomach. 139 (1) 011007. https://doi.org/10.1115/1.4034342
12. Ferster, K. K., Kirsch, K. L, Thole, K. A. (2018) Effects of geometry, spacing, and number of pin fins in additively manufactured microchannel pin fin arrays. J. Turbomach. 140(1): 011007. https://doi.org/10.1115/1.4038179
13. Parbat S., Min Z., Yang L., Chyu M. (2020) Experimental and numerical analysis of additively manufactured Inconel 718 coupons with lattice structure, J. Turbomach. 142 (6) (2020) 1–9. 061004. https://doi.org/10.1115/1.4046527
14. Haasenritter A, Weigand B. Optimization of the rib structure inside a 2-D cooling channel. 2004; ASME Paper GT2004–53187: 167-76. https://doi.org/10.1115/GT2004-53187
15. Khalatov, AA, Borisov, II, Severin, SD, Romanov, VV, Spitsyn, VY, Dashevskyy, YY. Heat Transfer, Hydrodynamics and Pressure Drop in the Model of a Blade Leading Edge Cyclone Cooling. 2011: ASME Paper GT2011–41150: 1057-1065. https://doi.org/10.1115/GT2011-45150
Abstract views: 263 PDF Downloads: 302
If the article is accepted for publication in the journal «Thermophysics and Thermal Power Engineering» the author must sign an agreementon transfer of copyright. The agreement is sent to the postal (original) or e-mail address (scanned copy) of the journal editions.
