Multi-region thermal characterization in LRE combustion chambers
Creators: name:  A. REMIDDI 
name:   G. INDELICATO 
name:   P.E. LAPENNA 
name:   F. CRETA 
Publisher: name: Proceedings of  the 9th European Conference for Aerospace Sciences. Lille, France, 27 June - 1 July, 2022
Year: 2022
Subjects: PROPULSION PHYSICS
LIQUID ROCKET ENGINE
COMBUSTION
MODELIZATION

description: Liquid Rocket Engines (LREs) are nowadays a widespread technology in the space industry, undergoing a deep innovation process to meet increasingly challenging requirements in terms of performance, limited budgets and reduced developing times. Due to the high pressure operating conditions typically employed for LREs, that lead to severe heat loads on the chamber walls, thermal management is a fundamental aspect for the design of both the engine and the cooling system, having a direct impact on both the propulsion system operating life and performance, and also preventing the occurrence of thermo mechanical failures. The engine characterization problem can be efficiently tackled by Computational Fluid Dynamics (CFD), that is increasingly replacing experiments in the early design stages. Several modeling solutions are needed to handle the multi scale problem, characterized by the interplay of a plethora of physical phenomena occurring in the LRE combustion camber, such as convective and radiative heat transfer, high pressure turbulent combustion and conduction through solid walls. In this contribution, we discuss the application of an efficient numerical framework for turbulent combustion and heat transfer modeling on 3D single and multi injector combustion chambers [1], as the one presented in Fig 1. The presented multi region, multi physics solver, is based on the opensource frameworks OpenFOAM and OpenSMOKE [2] and features a flamelet-based approach for turbulent combustion, also accounting for non adiabatic and non equilibrium effects [3], in order to reduce the stiffness induced by the finite rate kinetics of combustion. Concurrently, the stiffness induced by acoustics and boundary layers in the combustion chamber is reduced by resorting respectively to a low Mach number approach [4] and to thermal wall-functions adapted for flamelet-based solvers in LRE conditions [5]. Finally, a consistent Conjugate Heat Transfer (CHT) description is developed to guarantee the thermal balance and the temperature continuity across the interfaces between neighboring continua. The coupling procedure is in particular optimized for convection-dominated phenomena [6], as in the case of the considered capacitively cooled combustors, allowing for the simulation of long time windows of experimental and industrial relevance, maintaining reasonably limited the overall computational costs. Bibliography [1] N. Perakis, O. J. Haidn, Inverse heat transfer method applied to capacitively cooled rocket thrust chambers, International Journal of Heat and Mass Transfer 131 (2019) 150166. [2] A. Cuoci, A. Frassoldati, T. Faravelli, E. Ranzi, Opensmoke++: An object-oriented framework for the numerical modeling of reactive systems with detailed kinetic mechanisms., Computer Physics Communications 192 (2015) 237264. [3] P. E. Lapenna, R. Amaduzzi, D. Durigon, G. Indelicato, F. Nasuti, F. Creta, Simulation of a single-element GCH4/GOx rocket combustor using a non-adiabatic flamelet method, Joint Propulsion Conference (2018). [4] P. E. Lapenna, G. Indelicato, R. Lamioni, F. Creta, Modeling the equations of state using a flamelet approach in LRE-like conditions, Acta Astronautica 158 (2019) 460469. [5] G. Indelicato, P. Lapenna, A. Remiddi, F. Creta, An efficient modeling framework for wall heat flux prediction in rocket combustion chambers using non adiabatic flamelets and wall-functions, International Journal of Heat and Mass Transfer 169 (2021) 120913. doi:https://doi.org/10.1016/j.ijheatmasstransfer.2021.120913. [6] A. Remiddi, G. Indelicato, P. E. Lapenna, F. Creta, Development and validation of an efficient numerical framework for conjugate heat transfer in liquid rocket engines, AIAA Scitech Forum.