Experimental Studies in LENS I and X to Evaluate Real Gas Effects on Hypevelocity Vehicle Performance

Holden, Michael; Wadhams, Timothy; MacLean, Matthew; Mundy, Erik; Parker, Ronald A.

doi:10.2514/6.2007-204

Cited by 28 publications

(26 citation statements)

References 1 publication

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“…Therefore, to first-order we see very good agreement between our result and that observed in the LENS X expansion tunnel. 10 Calculated shapes at the conditions of the LENS X experiments are also in good agreement with the present measurements.…”

Section: Msl Shock Shapes At Angle Of Attacksupporting

confidence: 79%

“…To examine this discrepancy further, the same model was tested in the LENS X expansion tube facility at 5 MJ/kg. 10 Excellent agreement was obtained between simulations and experiments in the LENS X facility.…”

Section: A Cubrc Resultsmentioning

confidence: 59%

“…Recent studies revealed that the experimentally observed shock shape and stand-off distance differed significantly from numerical simulations over a 24" diameter MSL model for high-enthalpy test conditions at 5 and 10 MJ/kg in the LENS I reflected shock tunnel facility. 10 The computed shock stand-off distance for the 5 MJ/kg test condition was a factor of 2.25 times smaller than the experimental value as shown in Figure 1, for which this discrepancy is clearly visible. However, at a 2 MJ/kg test condition in the same facility, no such differences were observed.…”

Section: A Cubrc Resultsmentioning

confidence: 83%

See 2 more Smart Citations

Evaluation of Hypervelocity Carbon Dioxide Blunt Body Experiments in an Expansion Tube Facility

Sharma

Swantek

Flaherty

et al. 2011

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

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This work represents efforts to study high-enthalpy carbon dioxide flows in anticipation of the upcoming Mars Science Laboratory (MSL) and future missions. The current study extends the previous presentation of experimental results by the comparison now with axisymmetric simulations incorporating detailed thermochemical modeling. The work is motivated by observed anomalies between experimental and numerical studies in hypervelocity impulse facilities. In this work, experiments are conducted in the Hypervelocity Expansion Tube (HET) which, by virtue of its flow acceleration process, exhibits minimal freestream dissociation in comparison to reflected shock tunnels. This simplifies the comparison with computational result as freestream dissociation and considerable thermochemical excitation can be neglected. Shock shapes of the Laboratory aeroshell and spherical geometries are compared with numerical simulations. In an effort to address surface chemistry issues arising from high-enthalpy carbon dioxide ground-test based experiments, spherical stagnation point and aeroshell heat transfer distributions are also compared with simulation. The shock stand-off distance has been identified in the past as sensitive to the thermochemical state and as such, is used here as an experimental measureable for comparison with CFD and two different theoretical models. For low-density, small-scale experiments it is seen that models based upon assumptions of large binary scaling values are unable to match the experimental and numerical results. Very good agreement between experiment and CFD is seen for all shock shapes and heat transfer distributions fall within the non-catalytic and super-catalytic solutions.

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Section: Msl Shock Shapes At Angle Of Attacksupporting

confidence: 79%

Section: A Cubrc Resultsmentioning

confidence: 59%

Section: A Cubrc Resultsmentioning

confidence: 83%

See 1 more Smart Citation

Evaluation of Hypervelocity Carbon Dioxide Blunt Body Experiments in an Expansion Tube Facility

Sharma

Swantek

Flaherty

et al. 2011

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

View full text Add to dashboard Cite

show abstract

“…Recent studies revealed that the experimentally observed shock shape and stand-off distance differed significantly from numerical simulations over a 24" diameter MSL model for high-enthalpy test conditions at 5 and 10 MJ/kg in the LENS I reflected shock tunnel facility. 1 The computed shock stand-off distance for the 5 MJ/kg test condition was a factor of 2.25 times smaller than the experimental value. However, at a 2 MJ/kg test condition in the same facility, no such differences were observed.…”

Section: Introductionmentioning

confidence: 99%

Expansion Tube Investigation of Shock Stand-Off Distances in High-Enthalpy CO2 Flow Over Blunt Bodies

Sharma

Swantek

Flaherty

et al. 2010

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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The shock standoff distance in front of a blunt body is sensitive to the thermochemical state of the free stream. Recently, experimental and numerical studies have reported significantly different bow shock profiles in high-enthalpy carbon dioxide flows, a discrepancy that may result from non-equilibrium processes during flow acceleration in ground-based facilities. In this work, an expansion tube is used to create a Mach 5.7 carbon dioxide flow, matching the stagnation enthalpy and the velocity of previous studies. Images of shock layers are obtained for spherical geometries and a scaled model of the Mars Science Lander. Different sphere diameters are used in order to access non-equilibrium and equilibrium stagnation line shock profiles predicted by theory. Mars Science Lander profiles at zero angle of attack are in good agreement with available data from the LENS X expansion tunnel facility, confirming results are facility-independent for the same type of flow acceleration, and indicating the flow velocity is a suitable first-order matching parameter for comparative testing. Heat transfer measurements on the Mars Science Lander are also presented for the three different angle of attacks, and the results are consistent with previous studies. Initial results from a proposed organo-metallic based emission spectroscopy technique for bow shock layer interrogation are also presented.

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“…A shock-expansion tube (SET) has the potential to mitigate the aforementioned concerns to a certain extent and generate relatively clean test gas of very high enthalpy and hypervelocity because the test flow is not stagnated anywhere. A series of SETs have been set up around the world, e.g., X-2 and X-3 at the Queensland University [1][2][3][4], HYPULSE at GASL [5], LENS-X at CUBRC [6], JX-1 in Japan [7,8], a SET of low-speed range for the investigation of scramjet at Stanford University [9][10][11], and others [12]. A detonation-driven SET has been built at the State Key Laboratory of High Gas Dynamics (LHD) and has successfully generated hypervelocity test flows of up to 8 km/s and beyond [13,14].…”

Section: Introductionmentioning

confidence: 99%

On the numerical technique for the simulation of hypervelocity test flows

Hu¹,

Wang²,

Jiang³

et al. 2015

Computers & Fluids

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a b s t r a c tA shock-expansion tube (SET) is one of the major ground test facilities to generate really high-enthalpy and hypervelocity test flows. However, the strong shock wave may give rise to chemically non-equilibrium characteristic flow feature in a SET. In addition, the test time duration of a SET is extremely short which leads to difficulties in measurements and flow diagnostics. It is therefore appropriate to consider employing CFD approach, coupled with available experimental data, to determine the characteristic of the test flow in a SET. The dispersion-controlled dissipative scheme (DCD) is used for our simulation of chemically non-equilibrium flows associated with a SET. In this paper, the several numerical issues which occur in the computational investigation of the test flow in our SET facility are discussed. A new flux splitting algorithm based on local characteristics is worked out for the DCD scheme to mitigate any spurious oscillations. With the mentioned updated DCD scheme, the computed results compare well with the experimental data provided for validation.

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Experimental Studies in LENS I and X to Evaluate Real Gas Effects on Hypevelocity Vehicle Performance

Cited by 28 publications

References 1 publication

Evaluation of Hypervelocity Carbon Dioxide Blunt Body Experiments in an Expansion Tube Facility

Evaluation of Hypervelocity Carbon Dioxide Blunt Body Experiments in an Expansion Tube Facility

Expansion Tube Investigation of Shock Stand-Off Distances in High-Enthalpy CO2 Flow Over Blunt Bodies

On the numerical technique for the simulation of hypervelocity test flows

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