Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-19T13:07:02.672Z Has data issue: false hasContentIssue false

Binary collision of CMAS droplets—Part II: Unequal-sized droplets

Published online by Cambridge University Press:  08 July 2020

Himakar Ganti
Affiliation:
Department of Aerospace Engineering, University of Cincinnati, Cincinnati, OH45221-0070, USA
Prashant Khare*
Affiliation:
Department of Aerospace Engineering, University of Cincinnati, Cincinnati, OH45221-0070, USA
Luis Bravo
Affiliation:
Vehicle Technology Directorate, Army Research Laboratory, Aberdeen Proving Ground, MD21005, USA
*
a)Address all correspondence to this author. e-mail: prashant.khare@uc.edu
Get access

Abstract

The analysis presented in Part I of this study on the binary collision of equal molten calcium–magnesium–alumino–silicate (CMAS) droplets is extended to investigate the flow and interfacial dynamics of unequal CMAS droplet collision. Numerical investigations of head-on, off-center, and grazing collisions of two CMAS droplets of size 1 and 2 mm are conducted at pressure and temperature of 20 atm and 1548 K, respectively, that are representative of a gas-turbine combustor. At these conditions, the physical properties of CMAS are density, ρCMAS = 2690 kg/m3, surface tension between CMAS/air, σCMAS = 0.40 N/m, and viscosity, μCMAS = 11.0 N-s/m2. The primary difference between the CMAS and a fictitious fluid with viscosity 1/10 of CMAS was higher deformation for the lower viscosity case, leading to stretching and subsequent breakup of the liquid structure. These mechanisms are supported by the time evolution of surface, kinetic, and viscous dissipation energies.

Type
Invited Paper
Copyright
Copyright © The Author(s), 2020, published on behalf of Materials Research Society by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ganti, H., Khare, P., and Bravo, L.: Binary collision of CMAS droplets—Part I: Equal sized droplets. J. Mater. Res. (Focus Issue - Sandphobic Thermal/Environmental Barrier Coatings for Gas Turbine Engines), 115 (2020). doi:10.1557/jmr.2020.138.Google Scholar
Ghoshal, A., Murugan, M., Walock, M.J., Nieto, A., Barnett, B.D., Pepi, M.S., Swab, J.J., Zhu, D., Kerner, K.A., Rowe, C.R., Shiao, C.Y., Hopkins, D.A., and Gazonas, G. A.: Molten particulate impact on tailored thermal barrier coatings for gas turbine engine. J. Eng. Gas Turb. Power 140 (2018).CrossRefGoogle Scholar
Murugan, M., Ghoshal, A., Nieto, A., Walock, M., Bravo, L., Jain, N., Pepi, M., Swab, J., Zhu, D., Pegg, R.T., Rowe, C., Flatau, A., and Kerner, K.: Prevention of molten sand attack on thermal barrier coatings for rotorcraft gas turbine blades—A round robin test evaluation. In Annual Forum Proceedings (AHS International, Fairfax, VA, USA, 2018).Google Scholar
Libertowski, N., Plewacki, N., and Bons, J.P.: The effect of temperature and melting relative to particle deposition in gas turbines. In AIAA Scitech 2019 Forum, Jan 7 to 11, San Diego, CA, USA (American Institute of Aeronautics and Astronautics, Reston, VA, USA, 2019).CrossRefGoogle Scholar
Bravo, L.G., Xue, Q., Murugan, M., Ghoshal, A., Walock, M., and Flatau, A.: Particle transport analysis of sand ingestion in gas turbine jet engines. In 53rd AIAA/SAE/ASEE Joint Propulsion Conference, Jul 10 to Jul 12, Atlanta, GA, USA (AIAA, Reston, VA, USA, 2017); pp. 1–14.CrossRefGoogle Scholar
Jain, N., Bravo, L., Bose, S., Kim, D., Murugan, M., Ghoshal, A., and Flatau, A.: Turbulent multiphase flow and particle deposition of sand ingestion for high-temperature turbine blades. In Proceedings of the Summer Program, Jun 24 to Jul 20, Stanford, CA, USA (Center for Turbulence Research, Stanford, CA, USA, 2018); pp. 35–44.Google Scholar
Spitsberg, I., and Steibel, J.: Thermal and environmental barrier coatings for SiC/SiC CMCs in aircraft engine applications*. Int. J. Appl. Ceram. Technol. 1(4), 291301 (2004).CrossRefGoogle Scholar
Lee, K.N., Fox, D.S., Eldridge, J.I., Zhu, D., Robinson, R.C., Bansal, N.P., and Miller, R.A.: Upper temperature limit of environmental barrier coatings based on mullite and BSAS. J. Am. Ceram. Soc. 86(8), 12991306 (2003).CrossRefGoogle Scholar
Lee, K.N.: Current status of environmental barrier coatings for Si-based ceramics. Surf. Coat. Technol. 133–134, 17 (2000).Google Scholar
Murugan, M., Ghoshal, A., Walock, M., Nieto, A., Bravo, L., Barnett, B., Pepi, M., Swab, J., Pegg, R.T., Rowe, C., Zhu, D., and Kerner, K.: Microstructure based material-sand particulate interactions and assessment of coatings for high temperature turbine blades. In Proceedings of ASME Turbo Expo (IGTI), Charlotte, NC USA (ASME, New York, NY, USA, 2017).Google Scholar
Larry Fehrenbacher, D.K., Kutsch, J., Vesnovsky, I., Fehrenbacher, E., Ghoshal, A., Walock, M., Murugan, M., and Nieto, A.: Advanced environmental barrier coatings for SiC CMCs. In Advances in Ceramics for Environmental, Functional, Structural, and Energy Applications II, Vol. 266, edited by Mahmoud, M.M., Sridharan, K., Colorado, H., Bhalla, A.S., Singh, J.P., Gupta, S., Langhorn, J., Jitianu, A., and Jose Manjooran, N. (John Wiley & Sons, Hoboken, NJ, USA, 2019); pp 8393.Google Scholar
Song, W., Yang, S., Fukumoto, M., Lavallée, Y., Lokachari, S., Guo, H., You, Y., and Dingwell, D.B.: Impact interaction of in-flight high-energy molten volcanic ash droplets with jet engines. Acta Mater. 171, 119131 (2019).CrossRefGoogle Scholar
Singh, S. and Tafti, D.: Particle deposition model for particulate flows at high temperatures in gas turbine components. Int. J. Heat Fluid Flow 52, 7283 (2015).CrossRefGoogle Scholar
Pearson, D. and Brooker, R.: The accumulation of molten volcanic ash in jet engines, simulating the role of magma composition, ash particle size and thermal barrier coatings. J. Volcanol. Geotherm. Res. 389, 106707 (2020).CrossRefGoogle Scholar
Bravo, L., Jain, N., Khare, P., Murugan, M., Ghoshal, A., and Flatau, A.: Physical aspects of particle dynamics and deposition in turboshaft engines. J. Mater. Res. (under review), (2020).CrossRefGoogle Scholar
Liu, D., Zhang, P., Law, C.K., and Guo, Y.: Collision dynamics and mixing of unequal-size droplets. Int. J. Heat Mass Transfer 57, 421428 (2013).CrossRefGoogle Scholar
Tang, C., Zhao, J., Zhang, P., Law, C.K., and Huang, Z.: Dynamics of internal jets in the merging of two droplets of unequal sizes. J. Fluid Mech. 795, 671689 (2016).CrossRefGoogle Scholar
Tang, C., Zhang, P., and Law, C.K.: Bouncing, coalescence, and separation in head-on collision of unequal-size droplets. Phys. Fluids 24, 22101-122101-15 (2012).CrossRefGoogle Scholar
Pan, K.-L., Law, C.K., and Zhou, B.: Experimental and mechanistic description of merging and bouncing in head-on binary droplet collision. J. Appl. Phys. 103, 064901 (2008).CrossRefGoogle Scholar
Ashgriz, N. and Poo, J.Y.: Coalescence and separation in binary collisions of liquid drops. J. Fluid Mech. 221, 183204 (1990).CrossRefGoogle Scholar
Nikolopoulos, N. and Bergeles, G.: The effect of gas and liquid properties and droplet size ratio on the central collision between two unequal-size droplets in the reflexive regime. Int. J. Heat Mass Transfer 54, 678691 (2011).CrossRefGoogle Scholar
Yoshino, M., Sawada, J., and Suzuki, K.: Numerical simulation of head-on collision dynamics of binary droplets with various diameter ratios by the two-phase lattice kinetic scheme. Comput. Fluids 168, 304317 (2018).CrossRefGoogle Scholar
Notaro, V., Khare, P., and Lee, J.G.: Mixing characteristics of non-Newtonian impinging jets at elevated pressures. Flow Turbul. Combust. 102, 355372 (2019).CrossRefGoogle Scholar
Khare, P. and Yang, V.: Newtonian and non-newtonian liquid droplet breakup: Child droplet statistics. Proceedings of ICLASS 2015, 13th Triennial International Conference on Liquid Atomization and Spray Systems, Aug 23 to Aug 27, Tainan, Taiwan (2015).Google Scholar
Khare, P. and Yang, V.: Breakup of non-newtonian liquid droplets. In 44th AIAA Fluid Dynamics Conference, Jan 16 to Jan 20, Atlanta, GA, USA (AIAA, Reston, VA, USA, 2014).CrossRefGoogle Scholar
Gamertsfelder, J., Khare, P., and Bravo, L.G.: Investigation of atomization behavour of liquid monopropellants in pintle injectors. In ASME Turbo Expo, June 22–26, London, England (ASME, New York, NY, USA, 2020).Google Scholar
Chen, X., Ma, D., Khare, P., and Yang, V.: Energy and mass transfer during binary droplet collision. In 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, Jan 4 to Jan 7, Orlando, FL, USA (AIAA, Reston, VA, USA, 2011); pp. 1–14..CrossRefGoogle Scholar
Tryggvason, G., Scardovelli, R., and Zaleski, S.: Direct Numerical Simulations of Gas–Liquid Multiphase Flows (Cambridge University Press, New York, NY, USA, 2011).Google Scholar
Brackbill, J.U., Kothe, D.B., and Zemach, C.: A continuum method for modeling surface tension. J. Comput. Phys. 100, 335354 (1992).CrossRefGoogle Scholar