Numerical Simulation of Hot-Gas Side Heat Transfer Enhancement in Thrust Chambers by Wall Ribs

Betti, B.; Nasuti, Francesco; Martelli, Emanuele

doi:10.2514/6.2011-5622

Cited by 4 publications

(4 citation statements)

References 15 publications

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“…The rib efficiency defined by:

with

and

the integrated wall heat fluxes for the ribbed and smooth configuration, and

and

the surface of the ribbed and smooth wall, is estimated to

. This means that almost 80% of additional heat flux is extracted thanks to the ribbed liner for the same mean chamber diameter as often reported in the literature [ 3 , 10 , 11 , 12 ].…”

Section: Resultssupporting

confidence: 73%

“…JAXA published a RANS study of their two experimental thrust chambers [ 10 ]. Betti et al [ 12 ] numerically reproduced the ribbed NASA experiment [ 3 ] with a RANS approach. As the measurement was made in the cooling channel along the chamber, the RANS simulation of the cold flow was coupled to a 1D model for conduction in the liner and the cooling channel.…”

Section: Introductionmentioning

confidence: 99%

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Prediction of Wall Heat Fluxes in a Rocket Engine with Conjugate Heat Transfer Based on Large-Eddy Simulation

Potier

Duchaine

Cuenot

et al. 2022

Entropy

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Although a lot of research and development has been done to understand and master the major physics involved in cryogenic rocket engines (combustion, feeding systems, heat transfer, stability, efficiency, etc.), the injection system and wall heat transfer remain critical issues due to complex physics, leading to atomization in the subcritical regime and the interactions of hot gases with walls. In such regimes, the fuel is usually injected through a coaxial annulus and triggers the atomization of the central liquid oxidizer jet. This type of injector is often referred to as air-assisted, or coaxial shear, injector, and has been extensively studied experimentally. Including such injection in numerical simulations requires specific models as simulating the atomization process is still out of reach in practical industrial systems. The effect of the injection model on the flame stabilization process and thus on wall heat fluxes is of critical importance when it comes to the design of wall-cooling systems. Indeed, maximizing the heat flux extracted from the chamber can lead to serious gain for the cooling and feeding systems for expander-type feeding cycles where the thermal energy absorbed by the coolant is converted into kinetic energy to drive the turbo-pumps of the feeding system. The methodology proposed in this work to numerically predict the flame topology and associated heat fluxes is based on state-of-the-art methods for turbulent reactive flow field predictions for rocket engines, including liquid injection, combustion model, and wall treatment. For this purpose, high-fidelity Large Eddy Simulation Conjugate Heat Transfer, along with a reduced kinetic mechanism for the prediction of H2/O2 chemistry, liquid injection model LOx sprays, and the use of a specific wall modeling to correctly predict heat flux for large temperature ratio between the bulk flow and the chamber walls, is used. A smooth and a longitudinally ribbed combustor configuration from JAXA are simulated. The coupling strategy ensures a rapid convergence for a limited additional cost compared to a fluid-only simulation, and the wall heat fluxes display a healthy trend compared to the experimental measurements. An increase of heat transfer coherent with the literature is observed when walls are equipped with ribs, compared to smooth walls. The heat transfer enhancement of the ribbed configuration with respect to the smooth walls is coherent with results from the literature, with an increase of around +80% of wall heat flux extracted for the same chamber diameter.

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“…The rib efficiency defined by:

with

and

the integrated wall heat fluxes for the ribbed and smooth configuration, and

and

the surface of the ribbed and smooth wall, is estimated to

. This means that almost 80% of additional heat flux is extracted thanks to the ribbed liner for the same mean chamber diameter as often reported in the literature [ 3 , 10 , 11 , 12 ].…”

Section: Resultssupporting

confidence: 73%

Section: Introductionmentioning

confidence: 99%

Prediction of Wall Heat Fluxes in a Rocket Engine with Conjugate Heat Transfer Based on Large-Eddy Simulation

Potier

Duchaine

Cuenot

et al. 2022

Entropy

View full text Add to dashboard Cite

show abstract

“…The present solver has been validated in different operative conditions against experimental data. 29,30 Frozen flow assumption is adopted without aiming to describe the details of injection and combustion of propellants in the thrust chamber. The mixture of hot combustion products at chemical equilibrium composition enters the computational domain through the whole thrust chamber cross section and its chemical composition is kept constant through the chamber.…”

Section: A Hot Gas: Cfd Solvermentioning

confidence: 99%

Cooling Channel Analysis of a LOX/LCH4 Rocket Engine Demonstrator

Pizzarelli¹,

Betti

Nasuti

et al. 2014

50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

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A computational procedure able to describe the coupled hot-gas/wall/coolant environment that occurs in most liquid rocket engines is presented and demonstrated. The coupled analysis is performed by loose coupling of the two-dimensional axisymmetric Reynolds-Averaged Navier-Stokes equations for the hot-gas flow and the conjugate three-dimensional model for the coolant flow and solid material heat transfer in the regenerative cooling circuit. The latter model is in turn based on the coupled Reynolds-Averaged Navier-Stokes equations for the coolant flow and Fourier equation for the thermal conduction in the solid material. In this study, the thermal behavior of a regeneratively cooled oxygen/methane engine demonstrator is analyzed in detail. Starting from a nominal operative condition of the engine, different levels of channel surface roughness and coolant mass flow rate are considered in order to understand their influence on the heat transfer capability of the cooling system. Results show that the heat transfer can be markedly impaired if the operating parameters undergo rather minor changes with respect to the nominal condition

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“…Turbulence is described by means of the Spalart-Allmaras one-equation model [28], a constant turbulent Schmidt number is adopted to model turbulent diffusivity, and a constant turbulent Prandtl number is adopted to model turbulent conductivity. The present solver has been validated in different operative conditions against experimental data [29][30][31]. Frozen flow assumption is adopted without aiming to describe the details of injection and combustion of propellants in the thrust chamber.…”

mentioning

confidence: 99%

Development of Thrust Chamber Components for a System Analysis Tool

Leonardi¹,

Onofri²,

Nasuti³

et al. 2014

50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

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In this paper a new thrust chamber component for the object oriented tool EcosimPro is presented. The numerical approach consists of a finite volume formulation of the unsteady quasi one-dimensional Euler equations for multispecies flow coupled with finite-rate chemistry. The inviscid convective fluxes are treated with two schemes, specifically formulated for multispecies flows: the approximate Riemann solver of Roe and the AUSM+ -up. Both the schemes are implemented with a spatial accuracy up to the third order by means of the Monotonic Upstream Centered Scheme for Conservation Laws (MUSCL). The reaction mechanism presented consists of six species and eight reactions for the combustion of hydrogen and oxygen while time integration is left to the DASSL implicit solver embedded in EcosimPro. After the description of the numerical model, some validation test cases for the schemes and the finite-rate chemistry mechanism are presented. The component is then tested on the Space Shuttle Main Engine (SSME) Main Combustion Chamber (MCC) and the results are compared against those obtained with an already validated software. The tests show that the component is able to reach the expected steady-state solution in terms of both evolution of the thermodynamic properties and mixture composition and that the implicit solver is able to deal with the stiffness introduced by the source terms representing the finite-rate chemistry. The SSME MCC and its regenerative cooling channel are then modelled in EcosimPro. Limitations related with the use of classical semi-empirical correlations for the hot gas side heat transfer coefficient are highlighted and overcome through a coupling procedure, in which the solution coming from a CFD analysis of the MCC is coupled with those obtained with EcosimPro for the cooling channels. The results of this iterative procedure are compared with those available in open literature, showing that wall heat flux and wall temperature profile are in line with those obtained by other methods. Furthermore, an accurate calculation of the wall heat flux allows the cooling channel component presently available in EcosimPro to obtain results that are comparable with those proposed by higher fidelity models

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Numerical Simulation of Hot-Gas Side Heat Transfer Enhancement in Thrust Chambers by Wall Ribs

Cited by 4 publications

References 15 publications

Prediction of Wall Heat Fluxes in a Rocket Engine with Conjugate Heat Transfer Based on Large-Eddy Simulation

Prediction of Wall Heat Fluxes in a Rocket Engine with Conjugate Heat Transfer Based on Large-Eddy Simulation

Cooling Channel Analysis of a LOX/LCH4 Rocket Engine Demonstrator

Development of Thrust Chamber Components for a System Analysis Tool

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