Numerical Investigation of Flow and Combustion in a Single-Element GCH₄/GOX Rocket Combustor: Chemistry Modeling and Turbulence-Combustion Interaction

Abstract

A sub-scale GOx/GCH4 rocket combustor has been simulated by different groups using various numerical methods. The current contribution focuses on the effects of chemistry and combustion modeling on the turbulent flame shape and structure, as well as the resulting axial pressure profile and wall heat flux, for which experimental data are available. Two different kinetic schemes have been used, combined with various models for turbulence and turbulence-combustion interaction (TCI). To evaluate the impact of combustion chemistry, the schemes are first studied on canonical laminar flames and evaluated against a detailed chemical scheme. The results obtained by the different groups on the target configuration demonstrate the strong impact of the models and the consequences for pressure and wall heat flux prediction.

Numerical Investigation of Flow and Combustion in a Single Element GCH4/Gox Rocket Combustor

“…As part of the effort, studies of more specific aspects of the modeling approaches have been conducted in separate publications. The aspect of turbulence modeling is discussed in the publication by Chemnitz et al 3 The modeling of chemistry and turbulence chemistry interaction is presented by Maestro et al 4 The efforts to simulate the test case using Large Eddy Simulation (LES) are presented by Müller et al 5…”

Delayed Detached Eddy Simulations with Tabulated Chemistry for Thermal Loads Predictions

“…The reader should notice that, while χ is close to zero in the near-wall field, the condition χ 0 should not be replaced in the table by the equilibrium assumption, as it would lead to a full recombination of CO toward CO 2 at wall and an excessive heat release. The accuracy of the solution assuming a single χ value is expected to suffer in the nearinjector region, because values up to χ 20;000 s −1 are observed for this test case [12]. The left-hand-side plot of Fig.…”

“…In particular, recent efforts were initiated by the academic community to provide experimental data for gaseous CH 4 ∕O 2 subscale combustion chambers. A first experimental setup involved a capacitively cooled single-injector combustion chamber [7][8][9][10], which was the object of numerous numerical studies first in the Reynolds-averaged Navier-Stokes (RANS) context [11][12][13][14][15] and later on in large-eddy simulation (LES) [16][17][18]. The original chamber was modified to allocate a film cooling slot [19], in order to investigate film cooling efficiency under different ratio of oxidizer to fuel (ROF) and chamber pressures.…”

“…The literature shows that a wide variety of combustion models coupled with RANS [22][23][24][25][26][27] and LES [28] could deliver reasonable results in terms of wall heat flux prediction. Nevertheless the overall trend shows that the quality of the prediction of wall heat flux and axial pressure distribution depends on the interaction between three models: the (subgrid) turbulence model [15], the chemical reaction mechanism, and the turbulence-chemistry interaction model [12,28]. With a view to offering the industry an attractive tool based on open-source libraries (OpenFOAM [29]), this work investigates the prediction quality of a hybrid RANS/LES model, namely, the improved delayed detached eddy simulation (IDDES) of Shur et al [30].…”

Collaborative Research for Future Space Transportation Systems

“…A considerable effort has been made towards the development and validation of predictive tools which are sufficiently accurate but still require an acceptable numerical effort. The main emphasis was laid on models for chemical kinetics and turbulence, and in particular turbulence/chemistry interaction [54,55]. One frequently simulated test case was the PennState preburner combustor [56], see Fig.…”