Numerical Investigation of Rocket Engine Combusting Flowfields

Ranuzzi, Giuliano; Cutrone, Luigi; Cardillo, Daniele; Invigorito, Marco

doi:10.2514/6.2016-2147

Cited by 6 publications

(4 citation statements)

References 7 publications

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“…The change in the thermophysical properties of oxygen during the transition from subcritical to supercritical state was coupled to the solver using UDF (User Defined Function). In the published article (Song and Sun, 2016), we compared the heat flux distribution on the gas-side wall calculated by this CFD method with the experimental data in the literatures (Locke et al, 2007;Ranuzzi et al, 2016), and the results agree well. For the LOX/methane combustion chamber discussed in this article, the heat flux distribution on the gas-side wall is given in Fig.…”

Section: Thermo-structural Analysis Schemementioning

confidence: 55%

Effects of thermal and pressure loads on structural deformation of liquid oxygen/methane engine combustion chamber

Liu¹,

Sun²,

Song

et al. 2020

JTST

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To investigate the influences of thermal and pressure loads on the structural deformation of the Liquid Oxygen/Methane rocket engine combustion chamber, a complete thermo-structural analysis scheme including fluid-thermal analysis and structural finite element analysis is developed and then verified to be reasonable. By conducting fluid-thermal analysis, the detailed distribution of the thermal and pressure loads is obtained. These results are utilized as body loads and surface loads in structural finite element analysis. Then, the stress-strain responses of the combustion chamber and the accumulation process of the deformation induced by thermal and pressure loads were studied in detail. The main conclusions are as follows: Under the action of thermal loads alone, the most pronounced residual mechanical strain is at the upstream of the nozzle divergent segment. Reducing the temperature difference between the hot run and the pre-cooling phase can be a feasible improvement measure for this issue. Under the action of the pressure loads alone, the bottom of the cooling channel bends toward the centerline of the combustion chamber. Properly increasing the thickness of the channel bottom near the coolant inlet is deemed to be an effective measure to reduce this bending trend. Under the combined action of thermal and pressure loads, the structural deformation characteristics are determined by the combination of thermal loads and pressure loads, rather than mainly by thermal loads. The accumulation rate of mechanical strain at the channel bottom corner is much rapider than the other positions. Turning the sharp bottom corner of the cooling channel into rounded corner is an alternative method of suppressing strain accumulation.

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Section: Thermo-structural Analysis Schemementioning

confidence: 55%

Effects of thermal and pressure loads on structural deformation of liquid oxygen/methane engine combustion chamber

Liu¹,

Sun²,

Song

et al. 2020

JTST

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“…These are modeling, first, the formation, the breaking up and the entrainment of the liquid film on the melting fuel surface; and, second, the transformation of the melted fuel into a gaseous species participating in the combustion process. These demanding efforts have probably discouraged researchers, so drastic simplifications are usually introduced, such as giving the regression rate calculation away by assuming it from experiments [31,[37][38][39], or limiting the analysis to one-dimensional integral-differential models [40]. In other cases, by observing that the melted paraffin wax is in the supercritical state under the hybrid rocket chamber characteristic conditions (thus, surface tension vanishes and the sharp distinction at droplets surface between gas and liquid phases disappear), the melted layer break up and, subsequently, the liquid paraffin injection in the flowfield is disregarded, supposing that the entrainment is part of the turbulent mixing process [41,42].…”

Section: State Of the Art Of Cfd Techniques For Rocket Internal-ballimentioning

confidence: 99%

“…(6) From the results of this simulation, the convective heat flux to the wall is evaluated, so that Equations (25)- (27) in the case of standard polymers, or Equations (30)- (32) and (37) in the other case of liquefying fuels, can be solved simultaneously to compute the new distributions of the variables along the grain surface and, accordingly, the mass flux distribution either from Equation (24), or Equations (34) and (35), respectively, along with the volume source terms in Equations (38) and (39) required in the latter case.…”

Section: Solution Strategymentioning

confidence: 99%

The Application of Computational Thermo-Fluid-Dynamics to the Simulation of Hybrid Rocket Internal Ballistics with Classical or Liquefying Fuels: A Review

et al. 2019

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The computational fluid dynamics of hybrid rocket internal ballistics is becoming a key tool for reducing the engine operation uncertainties and development cost as well as for improving experimental data analysis. Nevertheless, its application still presents numerous challenges for the complexity of modeling the phenomena involved in the fuel consumption mechanism and its coupling with the chemically reacting flowfield. This paper presents a review of the computational thermo-fluid-dynamic models developed for the internal ballistics of hybrid rockets burning gaseous oxygen with classical polymeric or paraffin-based fuels, with a special focus on the interaction between the fluid and the solid fuel surface. With the purpose of predicting the local fuel regression rate, which is the main parameter needed for the hybrid rocket design, the model is coupled with an improved gas/surface interface treatment based on local mass, energy and mean mixture-fraction balances, combined to either a pyrolysis-rate equation in the case of classical polymers, or to an additional equation for the liquid paraffin entrainment fraction of the total fuel consumption rate. A number of experimental test cases obtained from the static firing of two different laboratory-scale rockets are simulated to determine the models’ capabilities, showing very good agreement between the calculated and measured fuel regression rates with both standard pyrolyzing and liquefying fuels. The prediction of the chamber pressure measured with paraffin fuel resulted in it being more cumbersome for the single-phase flow assumption. The advantages and limitations of the models are discussed.

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“…Modeling strategies available in the literature range from the algebraic models of Marxman's theory [8] and Karabeyoglu's theory for liquefying fuels [4,5] to Reynolds-averaged Navier-Stokes (RANS) simulations employing different sub-models [9], while direct numerical simulation (DNS) studies are limited to fundamental investigations such as the instability of supercritical liquid films in HRE conditions [10]. RANS simulations tipically rely either on the assignment of a prescribed fuel mass flow rate [11][12][13][14][15], or employ a parametric gas-surface interaction model, i.e., tuned to match one experimental firing test [16,17]. All previous numerical studies dealing with paraffin-wax neglect radiation effects, which can be prominent in HRE combustion chambers [18][19][20], and, in addition, neglect its thermal cracking reaction by directly injecting ethylene from the fuel grain surface to the flow field.…”

Section: Introductionmentioning

confidence: 99%