Design support for advanced storable propellant engines by ROCFLAM analyses

Knab, O.; Froehlich, Annette; Wennerberg, D.

doi:10.2514/6.1999-2459

Cited by 10 publications

(5 citation statements)

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“…For the hot gas side, Astrium applies the axisymmetric in-house multiphase Navier Stokes code Roc §am-II, which is a merger from two previous in-house codes, namely, CryoROC [3] and ROCFLAM [4]. While CryoROC treated problems with cryogenic propellants H 2 and LOx (liquid O 2 ), ROCFLAM was mainly used to model storable propellant problems, especially MMH/NTO (monomethylhydrazine / nitrogen tetroxide) thrust chambers.…”

Section: Applied Toolsmentioning

confidence: 99%

Consideration of real gas effects and condensation in a spray-combustion rocket-thrust-chamber design tool

Frey¹,

Kniesner²,

Knab³

2011

Progress in Propulsion Physics

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For the prediction of hot gas side heat transfer in rocket thrust chambers, Astrium Space Transportation (ST) uses the second generation multiphase Navier Stokes solver Roc §am-II. To account for real-gas and condensation e¨ects, pressure-dependent and even multiphase §uid data are included in the chemistry tables used by the code. Thus, the changing §uid properties near the two-phase region as well as transformation from gaseous to liquid and even solid state are re §ected properly. Heat §ux measurements for a dedicated subscale test campaign with strongly cooled walls show a clearly increasing heat load as soon as the combustion gases condense at the wall, due to the released latent heat of condensation. Corresponding coupled Roc §am-II/CFX simulations show a good quantitative agreement in heat §ux for load cases with and without condensation, showing the ability of the code to correctly simulate §ows in the real-gas and even inside the two-phase region.

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Section: Applied Toolsmentioning

confidence: 99%

Consideration of real gas effects and condensation in a spray-combustion rocket-thrust-chamber design tool

Frey¹,

Kniesner²,

Knab³

2011

Progress in Propulsion Physics

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“…A more detailed description of the numerical model is given in [2]. The applicability of the model for the simulation of MMH and NTO combustion has been demonstrated by several authors [7][8][9][10] in the past. …”

Section: B Numerical Methodologymentioning

confidence: 99%

Impact of Injector Mass Flow Fluctuations on Combustion Dynamics in Liquid Engines

Sattelmayer

Schmid

Schulze

2015

Journal of Spacecraft and Rockets

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Reynolds-averaged Navier-Stokes simulations were carried out to study the influence of acoustically driven injector mass flow fluctuations on combustion dynamics in a liquid propellant rocket engine. First, a framework of transfer functions is introduced, showing the links between pressure fluctuations in the chamber and resulting heat release modulation on the basis of the subprocesses involved. An analytical model for the injector admittance is evaluated, and computational-fluid-dynamics results for a single-injector configuration are obtained. The impact of mass flow fluctuations on evaporation dynamics and on heat release modulation is studied for four load points. Results show that the combustion dynamics are controlled by the droplet evaporation time. Dynamic mode decomposition results explain the convective transport of the droplets and give a detailed insight into the fluctuating fields. A weak mutual influence of the fuel evaporation is observed, whereas the fluctuations of the heat release rate are governed by the oxidizer evaporation rate. Evaporation rates and heat release rates are found to be linearly dependent on the mass flow excitation amplitude allowing for the superposition of transfer functions. Finally, a flame transfer function in the form of a low-pass filter is derived, providing a linear feedback model as input for low-order combustion instability assessment tools.

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“…with the constants A FR ¼ 3:5 Á 10 9 s À1 and E FR =R ¼ 52, 900 K. 39 The computations are conducted with ANSYS CFX 15.0 using RANS computations, the Eddy dissipation combustion model as well as the Soave-Redlich-Kwong equation of state for the description of real gas effects.…”

Section: Single Injector Computationsmentioning

confidence: 99%

Linear stability assessment of a cryogenic rocket engine

Schulze¹,

Sattelmayer²

2017

International Journal of Spray and Combustion Dynamics

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The linear high frequency stability of DLR's cryogenic H 2 /O 2 BKD test chamber is assessed using a hybrid computational fluid dynamic/computational aeroacoustic methodology, which is based on single flame simulations for the generation of an adequate mean flow and for the calibration of feedback models as well as on frequency space transformed linearized Euler equations. The application of a realistic mean flow field including combustion explains the spatial separation of transverse modes into a near face plate mode, which is found linearly unstable under certain operation conditions for the first transverse and a rear part mode. The axial mode shape length as well as eigenfrequencies is affected by propellant injection specifications and, in consequence, decisively influence pressure and transverse velocity sensitive dynamic flame response. The stability assessment procedure is finally applied to four operation conditions and the linear stability is predicted for the first transverse mode.

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Design support for advanced storable propellant engines by ROCFLAM analyses

Cited by 10 publications

References 0 publications

Consideration of real gas effects and condensation in a spray-combustion rocket-thrust-chamber design tool

Consideration of real gas effects and condensation in a spray-combustion rocket-thrust-chamber design tool

Impact of Injector Mass Flow Fluctuations on Combustion Dynamics in Liquid Engines

Linear stability assessment of a cryogenic rocket engine

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