Optically Resolved Fuel Regression of a Clear Polymethylmethacrylate Hybrid Rocket Motor

Mechentel, Flora S.; Hord, Blake; Cantwell, Brian

doi:10.2514/1.b37805

Cited by 12 publications

(3 citation statements)

References 14 publications

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“…It has a higher glass transition point compared to other commonly investigated solid fuels, like HTPB, which makes it stronger but also makes it more brittle [31,32]. PMMA is also naturally transparent when cast and machined, which has led to it being used for partially optical investigations of combustion processes in hybrid rockets without sacrificing the standard center-perforated, axisymmetric, fuel grain design [33]. It can also be extruded into a filament suitable for 3D printing; however, this causes it to lose its transparency preventing optically accessible investigations through the fuel grain [34,35].…”

Section: Solid Fuel Combustionmentioning

confidence: 99%

Supersonic Combustion of Solid Fuels

Schlussel,

Gallegos,

Young

2024

Journal of Propulsion and Power

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Supersonic combustion of solid fuels is investigated experimentally using a rectangular-cross-section combustor in the context of understanding ignition characteristics, studying fuel regression, and determining operating conditions. Fuel grains consisted of 3D printed polymethyl-methacrylate of varying geometry. Specifically, the cavity flameholder dimensions are systematically studied to develop a flammability map. Initial examinations reveal that a longer and larger cross-sectional area of the flameholding zone in the fuel grain creates the most optimal conditions for ignition and sustained flameholding. The longer and larger flameholding zone also creates conditions for faster time-averaged regression rates. The ignition characteristics and fuel regression are also examined by varying inlet temperatures of the air, which showed that a higher inlet temperature is conducive to sustained ignition, as well as higher fuel regression rates. This work extends the available literature on supersonic combustion of solid fuels to lower temperatures than has previously been reported.

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Section: Solid Fuel Combustionmentioning

confidence: 99%

Supersonic Combustion of Solid Fuels

Schlussel,

Gallegos,

Young

2024

Journal of Propulsion and Power

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“…Research in hybrid rocket engines is gaining momentum in recent years owing to experimental and numerical advances, and to an increasing number of test flights [1][2][3][4][5][6]. Hybrid rockets, which are propulsion devices burning a solid fuel and a gaseous or liquid oxidizer, are considered a promising alternative to liquid or solid propulsion for applications, including sounding rockets, space engines, auxiliary power units, and boosters [7,8].…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulations of the Internal Ballistics of Paraffin–Oxygen Hybrid Rockets at Different Scales

2021

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Hybrid rockets are considered a promising future propulsion alternative for specific applications to solid or liquid rockets. In order to raise their technology readiness level, it is important to perform predictive numerical simulations of their internal ballistics. The objective of this work is to describe and validate a numerical approach based on Reynolds-averaged Navier–Stokes simulations with sub-models for fluid–surface interaction, radiation, chemistry, and turbulence. Particular attention is given to scale effects by considering two different paraffin–oxygen hybrid rocket engines and a simplified grain evolution approach from the initial to the final port diameter. Moreover, a mild sensitivity of the computed regression rate to paraffin’s melting temperature, surface radiation emissivity, and Schmidt numbers is observed. Results highlight the increasing importance of radiation effects at larger scales and pressures. A numerical rebuilding of regression rate and pressure is obtained with simulations at the time-space-averaged port diameter, producing a reasonable agreement with the available experimental data, but a noticeable improvement is obtained by considering the grain evolution in time.

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“…Owing to its relatively simple depolymerization and thermal decomposition behavior, poly(methyl methacrylate) (PMMA) has been studied for several decades by both the fire science and propulsion communities [8][9][10][11][12][13][14][15][16]. Since the pyrolysis kinetics of PMMA are not complicated by charring or cross-linking behavior, its constituent monomer methyl methacrylate (MMA, C 5 H 8 O 2 ) accounts for nearly 95% of its pyrolysis products, historically providing a tractable and accessible modeling framework for PMMA combustion.…”

mentioning

confidence: 99%