Interactions of Single-Nozzle Sonic Propulsive Deceleration Jets on Mars Entry Aeroshells

Alkandry, Hicham; Boyd, Iain D.; Reed, Erin M.; Codoni, Joshua R.; McDaniel, James C.

doi:10.2514/6.2010-4888

Cited by 11 publications

(12 citation statements)

References 13 publications

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“…Calculated coefficient of drag (C D ) and total axial force (sum of C D and C T ) for the sonic peripheral 4-jet configuration and sonic single centerline (Central) jet configuration are shown in Figure 14. As shown in this figure, C D decreases when the peripheral jets are turned on for C T = 0.5 and 1.5; however, the decrease is considerably less than the previous reported [18] single centerline jet case also shown in this figure. The total axial force in the 4-jet peripheral case increases, even for C T = 0.5, unlike the single centerline (Central) sonic case, which can be seen to decrease for low C T .…”

Section: B Numerical Simulation Comparisonscontrasting

confidence: 47%

“…Experimental results will be compared with numerical simulations from the University of Michigan. Numerical simulations are executed using LeMANS, a parallelized CFD code developed at the University of Michigan for simulating hypersonic reacting flows [15][16][17][18]. LeMANS solves the laminar three-dimensional Navier-Stokes equations on unstructured computational grids, including thermo-chemical nonequilibrium effects.…”

Section: Cfd (University Of Michigan)mentioning

confidence: 99%

“…The finite-volume method applied to unstructured grids is used to solve the set of partial differential equations. Time integration is performed using a point implicit or line implicit method [18].…”

Section: Cfd (University Of Michigan)mentioning

confidence: 99%

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Investigations of Peripheral 4-Jet Sonic and Supersonic Propulsive Deceleration Jets on a Mars Science Laboratory Aeroshell

Codoni

Reed

McDaniel

et al. 2011

49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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With the launch of Mars Science Laboratory (MSL), scheduled for 2011, Viking technology developed in the 1970's is reaching its limits for entry, descent and landing (EDL) on Mars, necessitating research and development of other technologies for decelerating high mass Mars entry systems (HMMES), such as propulsive deceleration (PD) jets. In this paper planar laser-induced iodine fluorescence is utilized to obtain qualitative flow visualization images and quantitative PD jet mole fraction images of peripheral sonic and supersonic PD jet models in Mach 12 flow and compared to CFD computations. The models are 0.22% of the MSL frontal area, with Mach 1 and Mach 2.66 jets on the frontal aeroshell of the model, oriented normal to the hypersonic flow. The interactions of PD jets with a Mach 12 freestream flow are visualized with coefficients of thrust (C T ) varying from 0.5 to 3.0 in increments of 0.5. It was found that as C T increases the shock stand-off distance increases for both sonic and supersonic cases, with the supersonic distance at a C T = 3.0 being 17% greater than the sonic distance. The jet penetration distance was measured to be 50% greater for the supersonic case at a C T = 3.0. Experimental results were compared with CFD calculations of the sonic 4-jet configuration. Very good comparison was shown in the streamline patterns and jet mole fraction distributions. Using the validated CFD model, preliminary calculations showed that the drag coefficient for the 4-jet peripheral case was 3 times larger than that for the single centerline jet case at a C T of 0.5 and 6 times larger at a C T of 1.5, both with sonic exit conditions and the same total mass flow rate. The preservation of the vehicle drag was attributed to the normal bow shock between the peripheral jets which does not exist in the single centerline jet. The total axial force coefficient (sum of C T and C D ) was calculated to be twice as large for the peripheral 4 sonic jets as for the single sonic centerline jet at a C T of 0.5 and 50% larger at a C T of 1.5. This result suggests that, for the same total mass flow rate and sonic exit Mach number, the propulsive deceleration performance of the peripheral 4-jet PD design will be considerably greater relative to the single centerline PD jet. This result is important for the design of PD jet decelerators for EDL for future HMMES missions.

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Section: B Numerical Simulation Comparisonscontrasting

confidence: 47%

Section: Cfd (University Of Michigan)mentioning

confidence: 99%

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Investigations of Peripheral 4-Jet Sonic and Supersonic Propulsive Deceleration Jets on a Mars Science Laboratory Aeroshell

Codoni

Reed

McDaniel

et al. 2011

49th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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“…This shielding creates a low-pressure region between the jet boundary and the aeroshell, resulting in reduced aerodynamic drag force with increasing thrust coefficient [22]. References [22] and [23] show that the LeMANS calculations agree very well with the measured fluorescence images, both with respect to the streamline shapes and the shock standoff distance. These very good comparisons provide confidence that LeMANS is accurately capturing the details of the flowfield and can be used to calculate values, such as the drag coefficient C D , that cannot be measured in the experiment.…”

Section: A Central Pd Jetmentioning

confidence: 67%

Propulsion Deceleration Studies Using Planar Laser-Induced Iodine Fluorescence and Computational Fluid Dynamics

McDaniel

Codoni

Reed

et al. 2013

Journal of Spacecraft and Rockets

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Future high-mass spacecraft entering the thin Martian atmosphere will exceed the capabilities of supersonic and subsonic parachutes and will incorporate other means of deceleration. Propulsive deceleration is one technology that is being considered. The interaction of the spacecraft aerodynamics with the propulsion deceleration jets has been shown to cause a decrease in drag coefficient with increasing thrust coefficient, which is not desirable for deceleration. Planar laser-induced iodine fluorescence images for a single-propulsion deceleration jet showed a lifting of the vehicle bow shock away from the aeroshell. Flowfield calculations showed that this lifting provided a shielding effect, preventing the freestream mass and momentum flux from reaching the aeroshell surface, creating a low-pressure region between the jet boundary and the aeroshell. With four peripheral propulsive deceleration jets, planar laserinduced fluorescence images and computational fluid dynamics calculations showed that the vehicle bow shock is maintained between the jets as the thrust coefficient is increased. This bow shock is responsible for greater drag preservation with the peripheral jets. The calculations also showed that high pressure is maintained between the peripheral jets. These results suggest that using a few peripheral propulsion-deceleration jets located near the aeroshell shoulder would provide the greatest drag preservation when using propulsive deceleration.

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“…Figure 1 shows a full hypersonic flowfield computed around a capsule taken from Ref. 6. The insert shows the post-shock, high-enthalpy, subsonic region considered in the present study.…”

mentioning

confidence: 99%

Computation of Surface Catalysis for Graphite Exposed to High-Enthalpy Nitrogen Flow

Anna

Boyd

2012

50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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The high temperatures on a hypersonic vehicle surface caused by heat loads encountered during (re-)entry through a planetary atmosphere require a reliable Thermal Protection System (TPS) that makes a good understanding of the physical and chemical processes essential for its design. Surface catalysis is a crucial chemical process that directly impacts aerothermal heating of the vehicle TPS. To study the effects of this process, a binary catalytic atom recombination model is implemented in a computational fluid dynamics (CFD) code. The study examines the effects of surface catalysis for graphite exposed to high enthalpy nitrogen flow. As expected, surface catalysis strongly affects the boundary layer gradients of temperature and species concentration, and heat transfer to the surface. A fully catalytic surface causes the heat flux to increase by a factor of approximately 3.5. The physical accuracy of the model is assessed using data from experimental tests conducted in the Inductively Coupled Plasma (ICP) Torch Facility at the University of Vermont. Comparisons are presented of computed results with measured experimental data for translational temperature and relative nitrogen atom number density in the flow in front of the test article. NomenclatureD 12 binary diffusion coefficient between species 1 and 2 [m 2 /s] J sp species diffusion flux [kg/m 2 /s] M mass flux [kg/m 2 /s] N sp number of species in the mixture [dimensionless number] T translational-rotational temperature [K] Y mass fraction [dimensionless number] h sp species enthalpy [J/kg] k B Boltzmann constant k w wall catalytic speed [m/s] m particle mass [kg] q total heat flux [W/m 2 ] q conv convective heat flux [W/m 2 ] q dif f diffusive heat flux [W/m 2 ] γ wall catalytic efficiency [dimensionless number] κ thermal conductivity [W/m/K] ρ density [kg/m 3 ] subscripts w wall value tr translational-rotational energy mode ve vibrational-electronic energy mode ∞ reference freestream conditions sp species value * Graduate Student, Student Member AIAA. † James E. Knott Professor, Fellow AIAA.

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Interactions of Single-Nozzle Sonic Propulsive Deceleration Jets on Mars Entry Aeroshells

Cited by 11 publications

References 13 publications

Investigations of Peripheral 4-Jet Sonic and Supersonic Propulsive Deceleration Jets on a Mars Science Laboratory Aeroshell

Investigations of Peripheral 4-Jet Sonic and Supersonic Propulsive Deceleration Jets on a Mars Science Laboratory Aeroshell

Propulsion Deceleration Studies Using Planar Laser-Induced Iodine Fluorescence and Computational Fluid Dynamics

Computation of Surface Catalysis for Graphite Exposed to High-Enthalpy Nitrogen Flow

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