Super-Orbital Re-entry in Australia: Laboratory Measurement, Simulation and Flight Observation

Buttsworth, David; Jacobs, Peter A.; Potter, Daniel; Mudford, N. R.; D’Souza, Mary; Eichmann, Troy N.; Jenniskens, Peter; McIntyre, Timothy J.; Jokic, Michael D.; Jacobs, Carolyn; Upcroft, Ben; Khan, Razmi; Porat, Hadas; Neely, Andrew J.; Löhle, Stefan

doi:10.1007/978-3-642-25688-2_5

Cited by 2 publications

(3 citation statements)

References 6 publications

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“…Comparison with preliminary experimental data in the UV measured with the AUS instrument at altitudes after convective peak heating. 36 NIRSPEC measured spectrally resolved data (∆λ=0.286 nm, FWHM 1.4 nm) between 960 nm and 1080 nm. The strong lines seen in this spectrum are nitrogen multiplets.…”

Section: Incident Spectra At the Dc-8 Position And Comparison Witmentioning

confidence: 99%

Radiation Modeling for the Reentry of the Hayabusa Sample Return Capsule

Winter

McDaniel

Chen

et al. 2012

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

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Predicted shock-layer emission signatures of the Japanese Hayabusa capsule during its reentry are presented for comparison with flight measurements made during an airborne observation mission using NASA's DC-8 Airborne Laboratory. For each altitude, lines of sight were extracted from flow field solutions computed using an inhouse high-fidelity CFD code, DPLR, at 11 points along the flight trajectory of the capsule. These lines of sight were used as inputs for the line-by-line radiation code NEQAIR, and emission spectra of the air plasma were computed in the wavelength range from 300 nm to 1600 nm, a range which covers all of the different experiments onboard the DC-8. In addition, the computed flow field solutions were post-processed with the material thermal response code FIAT, and the resulting surface temperatures of the heat shield were used to generate thermal emission spectra based on Planck radiation. Both spectra were summed and integrated over the flow field. The resulting emission at each trajectory point was propagated to the DC-8 position and transformed into incident irradiance. Comparisons with experimental data are shown.

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Section: Incident Spectra At the Dc-8 Position And Comparison Witmentioning

confidence: 99%

Radiation Modeling for the Reentry of the Hayabusa Sample Return Capsule

Winter

McDaniel

Chen

et al. 2012

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

View full text Add to dashboard Cite

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“…The calibrated comparison between the standard air shock layer and the shock layer with added species shows that the bands and bandheads between 350 and 400 nm do increase for the epoxy coated models, but only by at most double the height, and the N + 2 bandhead at 391 nm has not been clearly resolved to show a distinct species from the air shock layer [63]. An attempt was also made to measure the luminosity of the shock layer from visible emissions captured by the high-speed camera, but these are uncalibrated and only show the relative emission strength across the shock layer [64]. Calibrating this data would be difficult as the exact wavelength range is unknown, but a new imaging method was recently developed to capture the intensity radiating shock layer across two distance dimensions using the ICCD [52].…”

Section: Relevant X2 Experimental Campaignsmentioning

confidence: 99%

“…IR spectra were collected by a ground-based tracking camera [4] and UV spectra were recorded by the AUS spectrometer that flew on a NASA DC-8 aircraft [64]. The trajectory point required good quality data in both spectral regions, and due to optical interference from the spacecraft bus break-up in the UV data until 13:52:19.5 UTC [79], the selected trajectory point was 13:52:20 UTC, slightly after the peak heating point evident in the IR spectra at 13:52:19 UTC [4].…”

Section: Trajectory Point Selectionmentioning

confidence: 99%

Superorbital re-entry shock layers: flight and laboratory comparisons

Fahy¹

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Hypervelocity re-entry through the Earth's atmosphere surrounds an aeroshell with a radiating shock layer, which has complex and potentially critical interactions with the thermal protection system, the key component to the vehicle's survival. Aerothermodynamic re-entry flight data is rare, but the available radiation data has potential for replication in ground-based experimental and numerical testing, where flight equivalent conditions can be achieved. A greater understanding and ability to demonstrate the behaviour of re-entry vehicles will allow increased confidence in pre-flight laboratory predictions, design iterations based on testing and simulation, and an overall reduction in the thermal protection system (TPS) mass, therefore increasing the mass available for scientific payload. This thesis aims to replicate flight data from the unmanned Hayabusa and Stardust aeroshell re-entries in expansion tube experiments and numerical simulations, and assess the similarities and differences in the results. The flight data is in the form of infrared (IR) and ultraviolet (UV) spectra emanating from the bow shock, as captured by air-and ground-based observation missions.The experiments were performed in the X2 expansion tube, a hypervelocity impulse facility capable of producing flight equivalent conditions over a scaled aeroshell model for a brief test time. Prior to optical imaging tests, the conditions were designed through an iterative combination of analytical, experimental and numerical methods, based on binary scaling and enthalpy matching. Emissions from the radiating shock layers were captured by IR and UV spectroscopy, as well as two-dimensional intensity mapping through a narrow wavelength band filter, but the measurements were oriented differently to flight. The axisymmetry of certain imaging planes enabled the transformation of line of sight integrated intensities into radial quantities, which could describe the forebody shock layer and result in an integrated intensity comparable with integrated flight spectra.Numerical simulations must first model the flowfield before radiation modelling is possible. Compressible flow computational fluid dynamics (CFD) simulations were performed for the Hayabusa and Stardust flight vehicles at the selected trajectory points, and scaled models at idealised and simulated inflow conditions. Radiation spectra calculations were performed along the same lines of sight as imaged in experimental spectra, and over the entire flowfield to be comparable to flight data and experimental 2D imaging.iii The flight, experimental and numerical data combined for a series of comparisons to test the hypotheses that under binary scaling, spectral radiance along a line of sight is invariant, and radiative intensity scales with the square of the length scale. Spectra comparisons between experiment and CFD, and CFD and flight, tested the first hypothesis, and integrated intensity comparisons between experiment and CFD, and experiment and flight, tested the second hypothesis. Favourabl...

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Super-Orbital Re-entry in Australia: Laboratory Measurement, Simulation and Flight Observation

Cited by 2 publications

References 6 publications

Radiation Modeling for the Reentry of the Hayabusa Sample Return Capsule

Radiation Modeling for the Reentry of the Hayabusa Sample Return Capsule

Superorbital re-entry shock layers: flight and laboratory comparisons

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