Effect of pressure on hydrogen/oxygen coupled flame–wall interaction

Abstract

The design and optimization of liquid-fuel rocket engines is a major scientific and technological challenge. One particularly critical issue is the heating of solid parts that are subjected to extremely high heat fluxes when exposed to the flame. This in turn changes the injector lip temperature, leading to possibly different flame behaviors and a fully coupled system. As the chamber pressure is usually much larger than the critical pressure of the mixture, supercritical flow behaviors add even more complexity to the thermal problem. When simulating such phenomena, these thermodynamic conditions raise both modeling and numerical specific issues. In this paper, both subcritical and supercritical hydrogen/oxygen one-dimensional, laminar flames interacting with solid walls are studied by use of conjugate heat transfer simulations, allowing to evaluate the wall heat flux and temperature, their impact on the flame as well as their sensitivity to high pressure and real gas thermodynamics up to 100 bar where real gas effects are important. At low pressure, results are found in good agreement with previous studies in terms of wall heat flux and quenching distance, and the wall stays close to isothermal. On the contrary, due to important changes of the fluid transport properties and the flame characteristics, the wall experiences significant heating at high pressure condition and the flame behavior is modified.

Self-adaptive coupling frequency for unsteady coupled conjugate heat transfer simulations

“…However, since the temperature variations in combustion systems are of several hundreds Kelvins or even a couple of thousands Kelvins, the absolute level of wall temperature variations is not necessarily negligible. This is even significant in extreme conditions as met in high-pressure hydrogen/oxygen flames whose transient flame-wall interaction has recently been studied numerically with transient CHT simulations of 1D head-on quenching [7].…”

Multiphysics Simulation Combining Large-Eddy Simulation, Wall Heat Conduction and Radiative Energy Transfer to Predict Wall Temperature Induced by a Confined Premixed Swirling Flame

“…While subgrid-scale modeling efforts are still ongoing, the range of applications of such high-fidelity computations widens to new horizons such as multiphysics simulations of conjugate heat transfer (CHT). Several applications to turbine blades have been reported [9,10] as well as combustion cases [22,2,31]. The accurate prediction of heat flux and temperature at the combustor wall requires accounting for the coupling between the turbulent reactive flow, the heat conduction within the walls and the radiative energy transfer.…”

Assessment of External Heat Transfer Modeling of a Laboratory-Scale Combustor: Effects of Pressure-Housing Environment and Semi-Transparent Viewing Windows

“…Using a detailed approach such as large-eddy simulation (LES) in a multiphysics framework is a promising candidate to accurately predict the wall temperature field. Such a combination of LES and conjugate heat transfer (CHT) has already been applied to several combustion applications [18][19][20]. When radiative energy transfer must be accounted for, the LES code is coupled to a solver of the radiative transfer equation [21][22][23].…”