Advanced hybrid rocket motor experiments

Korting, P.A.O.G.; Schöyer, H.F.R.; Timnat, Y. M.

doi:10.1016/0094-5765(87)90009-9

Cited by 49 publications

(16 citation statements)

References 3 publications

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“…6 as a function of the total mass flux with some data from the literature, 18,26,27 all of them being relative to experiments involving polyethylene fuel. In the same figure the theoretical points are also reported.…”

Section: Experimental Findings and Discussionmentioning

confidence: 99%

Influence of a Conical Axial Injector on Hybrid Rocket Performance

Carmicino

Sorge

2006

Journal of Propulsion and Power

103

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This paper analyzes the results obtained from a series of static firings of a lab-scaled hybrid rocket in which gaseous oxygen was supplied into axial-symmetric polyethylene cylindrical grains through two different injector configurations: an axial conical subsonic nozzle and a radial injector. The axial injector is interesting because of its relatively easy design, the higher regression rates, and the noticeably stable motor operation. To exploit its qualities, not only the assessment of the regression rate but rather the entire behavior of the motor is required. For the investigated set of operating conditions, the instantaneous regression rates exhibit a time dependence caused by the impinging jet zone dynamics, while the average regression rates are higher and less mass flux dependent than those achieved with the radial injection motor and expected from the classical turbulent-boundary-layer diffusionlimited theory. A comparison to the data from the radial injector was further drawn in terms of combustion efficiency and fuel regression uniformity. Concerning combustion stability, some observations are made. The radial injector, at the same mass flux and pressure, produces lower regression rates, high pressure oscillations, and worse combustion efficiency, but more uniform fuel consumption. Nomenclatureof ultrasounds in reference conditions c * = characteristic exhaust velocity c * 0 = theoretical characteristic exhaust velocity calculated at O/F c * = theoretical characteristic exhaust velocity calculated at OF D = space average port diameter D 0 = port initial diameter D 2 = average port final diameter D 2x = local port final diameter d = diameter E a = activation energy F = motor thrust G = mass flux H v = effective heat of vaporization I m = mixing index L = grain length L c = prechamber length L * = chamber characteristic length l = exponent of the Reynolds number in the mixing index definition m = exponent of the geometrical ratio in the mixing index definitioṅ m f = fuel mass flow ratė m ox = oxidizer mass flow rate = isentropic one-dimensional mass flow rate through the nozzle N = number of data points in the port diameter profiles n = exponent of mass flux OF = spatially averaged oxidizer-to-fuel ratio OF = mean value of spatially averaged oxidizer-to-fuel ratios O/F = average oxidizer to average fuel mass ratio p a = ambient pressure p e = nozzle-exit pressure R = gas constant Re = Reynolds numbeṙ r = space average regression ratė r x = local regression rate s = fuel grain thickness T w = fuel surface temperature t = time V e = isentropic one-dimensional velocity at nozzle exit x = axial abscissa z = nondimensional axial abscissa (x/L) α = nozzle divergence cone half-angle M f = measured solid fuel mass loss M f = computed solid fuel mass loss t = time step t o = ultrasounds time of flight η = c * efficiency, ratio between the actual and theoretical c * th η 0 = c * efficiency calculated at O/F λ = momentum-thrust reduction coefficient μ = gas viscosity ρ f = solid fuel density σ = standard deviation...

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Section: Experimental Findings and Discussionmentioning

confidence: 99%

Influence of a Conical Axial Injector on Hybrid Rocket Performance

Carmicino

Sorge

2006

Journal of Propulsion and Power

103

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“…The equation governing the dynamics of the eddy viscosity is given in Eq. (5). The terms on the right hand side of this equation represents production, diffusion and destruction of eddy viscosity, respectively.…”

Section: Governing Equations and Numerical Solution Methodsmentioning

confidence: 99%

“…1. A number of researchers have attempted numerical simulation of the SFRJ combustion chamber; however all of them focused on the flow field within the chamber after the motor ignition [1][2][3][4][5][6][7][8][9][10][11]. This is due to complexities in simulating dynamics of the ignition process of this type of motors.…”

Section: Introductionmentioning

confidence: 98%

Igniter jet dynamics in solid fuel ramjets

Tahsini¹,

Farshchi²

2009

Acta Astronautica

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“…It is due to nonlinear burning of fuel with burn time. Various methods have been used by the researchers to determine the regression rate of hybrid rocket fuel such as ultrasonic technique [4][5][6][7][8][9][10][11][12], X-ray radiographic technique [7,9,[13][14][15], and weight loss method [16][17][18][19][20][21][22][23][24][25][26][27]. In an ultrasonic technique, an array of transducers will be needed to get the complete regression rate, which would increase the overall cost and complexity of the set up.…”

Section: Introductionmentioning

confidence: 99%