Transpiration Cooling Performance in LOX/Methane Liquid-Fuel Rocket Engines

Bucchi, Andrea; Bruno, Claudio; Congiunti, Alessandro

doi:10.2514/1.7587

Cited by 18 publications

(5 citation statements)

References 8 publications

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“…The material code calculates the coolant and matrix temperatures throughout the material thickness and along the material surface once the required wall temperature, T W (x), and the wall heat fluxes, q W (x), are inserted as boundary conditions. The heat exchange into the porous media depends on the mass flow rate, the coolant fluid properties, and material characteristics 14,18,19 . An iterative process extracts the injection conditions at the cold wall of the porous material keeping the wall temperature in the required range.…”

Section: Mathematical Models and Numerical Solutionsmentioning

confidence: 99%

“…The convective heat transfer coefficient has been calculated by relating the thermo-physical properties of the porous material (porosity and permeability) with those of the coolant fluid (thermal conductivity and viscosity) 18 . The boundary conditions are used to couple the solution of the boundary layer with the material code.…”

Section: Mathematical Models and Numerical Solutionsmentioning

confidence: 99%

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Numerical Investigation of Variable Transpiration Cooling Effectiveness in Laminar and Turbulent Flows for Hypersonic Cruise Vehicles

Brune

Hosder

Gulli

et al. 2013

51st AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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The thermal management of hypersonic air-breathing vehicles presents formidable challenges. Reusable thermal protection systems (TPS) are one of the key technologies that must be improved in order to use hypersonic vehicles as practical, long-range transportation systems. The active cooling systems, such as transpiration cooling, have to be considered for affordable, long duration flights to achieve efficient temperature reduction and coolant mass saving. With this technique, it is important to understand the physics that characterize the boundary layer and its interaction with the vehicle's surface. This paper investigates the effectiveness of a variable-velocity transpiration strategy for fully laminar, transitional, and fully turbulent flows over a 2-D blunt body with a cylindrical leading edge and a wedge region. The transitional flow cases are evaluated for a range of transition locations to see the influence of this parameter on the variable transpiration strategy introduced. For all flow types presented in this paper, a saw-tooth wall velocity distribution (variable transpiration strategy) is compared to a uniform-velocity transpiration approach. An equal amount of coolant usage has been imposed in order to compare the cooling effectiveness between both strategies for various flow types in different regions of the body. The results show that the uniform-velocity transpiration allows a reduction of 68% in the stagnation point heat flux and 77% for variable-velocity transpiration with respect to the no-transpiration case in both laminar and turbulent flow cases. The computational results show that the efficiency of the transpiration cooling is much higher in laminar flow compared to turbulent flow in regions downstream of the stagnation point. In such regions, for turbulent flows, the amount of total coolant must be increased by 110% (factor of roughly 2) to match the cooling efficiency observed in laminar flows. In addition to the analysis of cooling effectiveness, the thermal response of TPS material with the variable transpiration strategy is also investigated for both fully laminar and fully turbulent flows.A TOT = surface exposed to the flow, m 2 BC = boundary condition BL = boundary layer B 0 = permeability coefficient, m 2 C/C = carbon-carbon C p = specific heat at constant pressure, J/kg.K G = mass flow rate per unit of area, kg/m 2 .s H = material thickness, m k = thermal conductivity, W/m.K h V = heat transfer coefficient, W/m 3 .K = mass flow rate, kg/s = mass flux, kg/m 2 .s Nu = Nusselt number ODE = ordinary differential equation P = pressure, Pa q = heat flux, W/m 2 Re = Reynolds number r p = sphere radii that simulate porosity, m SP = stagnation point T = temperature, K TPS = thermal protection system t = time, s U = longitudinal velocity, m/s V = transversal velocity, m/s ∂ = partial derivative Δ = incremental ratio 51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2 ρ = density, kg/m 3 ε = porosity η = cooling efficiency factor Subscripts CF = coo...

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Section: Mathematical Models and Numerical Solutionsmentioning

confidence: 99%

Section: Mathematical Models and Numerical Solutionsmentioning

confidence: 99%

Numerical Investigation of Variable Transpiration Cooling Effectiveness in Laminar and Turbulent Flows for Hypersonic Cruise Vehicles

Brune

Hosder

Gulli

et al. 2013

51st AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

View full text Add to dashboard Cite

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“…To this end, the method employed by Bucchi, Bruno, and Congiunti, was employed using appropriate properties for hydrogen peroxide instead of methane (their original transpiration coolant of choice). 12 In this method, the effective convective heat transfer from Bartz is scaled relative to the baseline convective heat transfer coefficient according to The molecular weight factor (12) is dependent on the core gas and transpiration coolant gas molecular weights according to…”

Section: B Transpiration Cooling Analysismentioning

confidence: 99%

Design and Analysis of a High-Performance Hydrogen Peroxide Thrust Chamber Assembly

Stechmann¹,

Lim²,

Rotella³

et al. 2014

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

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Hydrogen Peroxide (H 2 O 2 ) bipropellant rocket engines have been in use since the 1950's in launch vehicles, sounding rockets, and as RATO (Rocket Assisted TakeOff) units for aircraft. Often, these engines function at a low chamber pressure using pressure-fed propellants, open-cycle turbo-pumps, or low-pressure closed-cycle turbo-pumps. As a result, hydrogen peroxide bipropellant rocket engines have generally had limited performance relative to other engine architectures. Modern advances in high-pressure catalyst bed design at Purdue's Zucrow Research Laboratories as well as select use of transpiration cooling have made it possible to improve upon prior art by operating with a high-performance closedcycle pump arrangement at high chamber pressure (3200 psia). This leads to higher specific impulse, lower weight, and smaller engine components. The following report describes a design study for the injector, combustion chamber, and nozzle assembly associated with a small, 5,000 lbf thrust engine using this high-pressure cycle concept with 90% hydrogen peroxide and RP-1 propellants. Engine cycle design, chamber sizing, cooling selection and analysis, performance analysis, and structural design and analysis are all discussed. While many elements of the engine design require additional development prior to manufacturing, this study shows that very high-pressure closed-cycle hydrogen peroxide bipropellant engines should be feasible. Nomenclaturea = char depth b = empirical coefficient C p = specific heat D = diameter G = mass flux h = heat transfer coefficient = mass flow MR = mass ratio MW = molecular weight n = empirical coefficient P = pressure St = Stanton number t = time T = temperature u = flow velocity w = empirical coefficient = expansion ratio = density

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“…Numerical investigations of the transpiration cooling by Glass 2 and Bucchi 3 , which have considered a constant wall heat-flux, highlight the importance of coupling the boundary layer flow to the thermal response of selected porous materials. The key-role of the aforementioned coupling has been also experimentally emphasized, first, by Martin Marietta Aerospace 4 and, later, by the German Aerospace Center (DLR) 5 .…”

Section: Introductionmentioning

confidence: 99%

Permeability Measurements of Complex Porous Structures for Reusable Thermal Protection Systems (Invited)

Gulli

Maddalena

McKelvey

et al. 2014

19th AIAA International Space Planes and Hypersonic Systems and Technologies Conference

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Reusable thermal protection systems are one of the key technologies that have to be improved in order to afford long-duration hypersonic flights. Transpiration cooling has been demonstrated to be one of the most promising active cooling techniques in terms of temperature decreasing and coolant mass saving. The coupling of the boundary layer with the thermal response of selected porous materials plays a crucial role in enabling the practical use of the transpiration cooling technique for reusable thermal protection systems. In this work, a novel test-rig for the non-intrusive characterization in terms of local permeability of a customized porous Carbon-Carbon nose-tip is proposed. The new concept of effective permeability, conceived as the local blowing capability of a porous structure with respect to a selected coolant fluid, is also introduced. The coolant (air) mass-fluxes blown from the porous surface of the specimen, and measured by a hot-film probe, are related to the average pressure gradient across the local material thickness by using the Darcy's law on prescribed locations. A parallel work, based on the X-Ray computed tomography scan of the prototype specimen, has been carried out with the purpose of defining the most important guidelines for the effective-permeability tests. Specifically, the calculation of the average porosity is used to define the minimum area to be probed with the hot-wire. The analysis of the statistical distribution of the void structures inside the C/C cone, coupled to the use of the theory of fluid-flow through perforated plates, is performed to determine the correct distance of the hot-wire from the wall. The results show permeability variation among the surveyed locations ranging from 6% to 172%. The effective-permeability map obtained allows classifying the prototype C/C mask as a semi-pervious structure. In particular, the higher effective permeability is located near the stagnation point region where two delaminations are located. The asymmetric blowing capability of the cone highlights the importance of characterizing the entire thermal protection system instead of defining the overall properties of the material, which can be drastically different at the full-scale level due to the geometry, the system integration and the intrinsic defectology due to the manufacturing process. Nomenclature= slope of the chart pressure gradient vs. Darcy's velocity, ( • / 2 ) = transversal distance from the wall, ( .) ℎ = channels' diameter, ( ) = diameter of the control points, ( .) = local specimen's thickness, ( .) 2 ̿ = permeability tensor, ( 2 ) = permeability for the r-direction, ( ) = length, ( ) = merging or coalescence distance, ( .) ̇ = measured flow rate, ( ) = network-mesh size, ( .) = external pressure, ( ) = internal-plenum pressure, ( ) = external-plenum pressure, ( ) 2 = coefficient of determination, (−) ℎ = Reynolds number based on the channel's diameter, (−) = time, ( ) = calibration temperature, ( ) = hot-film temperature, ( ) = measured temperature during permeability tes...

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Transpiration Cooling Performance in LOX/Methane Liquid-Fuel Rocket Engines

Cited by 18 publications

References 8 publications

Numerical Investigation of Variable Transpiration Cooling Effectiveness in Laminar and Turbulent Flows for Hypersonic Cruise Vehicles

Numerical Investigation of Variable Transpiration Cooling Effectiveness in Laminar and Turbulent Flows for Hypersonic Cruise Vehicles

Design and Analysis of a High-Performance Hydrogen Peroxide Thrust Chamber Assembly

Permeability Measurements of Complex Porous Structures for Reusable Thermal Protection Systems (Invited)

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