Conjugate Heat Transfer Analysis of a Combustion Chamber using ANSYS Computational Fluid Dynamics to Estimate the Thermocouple Positioning in a Chamber Wall

Authors: Muzna Tariq, Ihtzaz Qamar

Abstract:

In most engineering cases, the working temperatures inside a combustion chamber are high enough that they lie beyond the operational range of thermocouples. Furthermore, design and manufacturing limitations restrict the use of internal thermocouples in many applications. Heat transfer inside a combustion chamber is caused due to interaction of the post-combustion hot fluid with the chamber wall. Heat transfer that involves an interaction between the fluid and solid is categorized as Conjugate Heat Transfer (CHT). Therefore, to satisfy the needs of CHT, CHT Analysis is performed by using ANSYS CFD tool to estimate theoretically precise thermocouple positions at the combustion chamber wall where excessive temperatures (beyond thermocouple range) can be avoided. In accordance with these Computational Fluid Dynamics (CFD) results, a combustion chamber is designed, and a prototype is manufactured with multiple thermocouple ports positioned at the specified distances so that the temperature of hot gases can be measured on the chamber wall where the temperatures do not exceed the thermocouple working range.

Keywords: Computational Fluid Dynamics, CFD, conduction, conjugate heat transfer, CHT, convection, fluid flow, thermocouples.

References:

[1] R. Warren, "Design of thermocouple probes for measurement of rocket exhaust," Aeronautical and Maritime Research Laboratory, Victoria, Australia, 1994.
[2] K. G. A. K. S. Omori, "Wall temperature distribution calculation for a rocket nozzle contour," National Aeronautics and Space Administration, Washington, United States, 1972.
[3] M. N. Sabry, "Modeling Conjugate Heat Transfer," in 2010 3rd International Conference on Thermal Issues in Emerging Technologies Theory and Applications, Cairo, Egypt, 2010.
[4] C. K. Yuanhong Li Song, "Coupling conjugate heat transfer with in-cylinder combustion modeling for engine simulation," International Journal of Heat and Mass Transfer, vol. 54, no. 11-12, pp. 2467-2478, May, 2011.
[5] P. S. L. H. M. Fadl, "Full conjugate heat transfer modelling for steam turbines in transient operations," International Journal of Thermal Sciences, vol. 124, pp. 240-250, Feburary, 2018.
[6] M. F. L. He, "Multi-scale time integration for transient conjugate heat," International Journal for Numerical Methods in Fluids, vol. 83, no. 12, pp. 887-904, 2016.
[7] T. Perelman, "On conjugated problems of heat transfer," International Journal of Heat and Mass Transfer, vol. 3, no. 4, pp. 293-303, 1961.
[8] M. F. a. L. He, "On Large Eddy Simulation Based Conjugate Heat Transfer Procedure for Transient Natural Convection," Journal of Turbomachinery, vol. 139, no. 11, June, 2017.
[9] "ThermocoupleInfo.com," REOTEMP Instrument Corporation, (Online). Available:https://www.thermocoupleinfo.com/type-k-thermocouple.htm. (Accessed 25th August 2020).
[10] O. B. George P. Sutton, Rocket Propulsion Elements, A Wiley Inter-Science Publication.
[11] "ASM Aerospace Specification Metals Inc.," MatWeb, LLC, (Online). Available: http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MQ316A(Accessed 4th October 2020).