Sharp Edge Flight Experiment-II Instrumentation Challenges and Selected Flight Data

Gülhan, Ali; Siebe, Frank; Thiele, Thomas; Neeb, Dominik; Turner, John; Ettl, Josef

doi:10.2514/1.a32572

Cited by 22 publications

(12 citation statements)

References 20 publications

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“…According to HEATS results, a 1 mm offset in thermocouple depth resulted in approximately a 20 K temperature difference for the uncooled case. The flight attitude at this time was checked via the flush air data system [2], and it was found that the flight attitude could not be the origin of the differing temperatures on the opposite panels.…”

Section: In-flight Measurementmentioning

confidence: 99%

“…The TPS panels are supported in all directions by a central post and flexible standoffs at the four corners so that the panel's thermal expansion is not suppressed [11]. The aluminum substructure carries the in-flight measurement infrastructure such as thermocouple compensation, pressure transducers, and other sensors [2].…”

Section: Flight Experiments Setup and Instrumentationmentioning

confidence: 99%

“…To interpret the cooling effect of the transpiration, AKTiV is instrumented with thermocouples as well as pressure sensors and resistance thermometers [2]. The experiment, using a porous and permeable carbon fiber reinforced carbon (C/C) ceramic, is located on a panel of row C, as shown in Fig.…”

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confidence: 99%

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Transpiration-Cooled Hypersonic Flight Experiment: Setup, Flight Measurement, and Reconstruction

Böhrk

2015

Journal of Spacecraft and Rockets

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The present paper presents the in-flight measurement of the transpiration cooling experiment Aktive Kühlung durch Transpiration im Versuch (often referred to as AKTiV) flown on the suborbital reentry configuration Sharp Edge Flight Experiment II (often referred to as SHEFEX II). Thermal response of the structure is measured just upand downstream of a cooled sample with a noncooled reference setup on the opposite side of the vehicle. The measurement shows that the heat flux is reduced upon coolant exhaust. The maximum temperature reduction with 87 K is observed on the porous sample, while downstream the sample, the temperature is reduced by 75 K by film cooling. This corresponds to cooling efficiencies of 58 and 42% on the sample and downstream, respectively. The evaluation is supported by the semi-analytical tool HEATS, based on a transient heat balance at the surface. Comparison of the results with HEATS shows that the heat flux predicted with HEATS is in good concurrence with the measured temperatures on the cooled sample, as well as upstream and downstream with a maximum deviation by 14%. The analysis suggests that the flow condition around the sharp-edged, faceted vehicle remained laminar longer than expected. Nomenclaturem M = Mach number, -_ m = mass flow rate, kg∕s Nu = Nusselt number, -Pr = Prandtl number p = pressure, Pa R = gas constant, J∕kg · K Re = Reynolds number, -r = recovery factor, -_ q = heat flux, W∕m 2 St = Stanton number, -T = temperature, K t = time, s u = velocity, m∕s α A = heat transfer coefficient, W∕m 2 · K α V = heat transfer coefficient, W∕m 3 · K ϵ = emissivity, -η = cooling efficiency, -κ = isentropic coefficient, -λ = thermal conductivity, W∕m · K μ = dynamic viscosity, Pa · s ρ = density, kg∕m 3 σ = Stefan-Boltzmann constant, W∕m 2 · K 4 ϕ = porosity, -Subscripts C = at panel C c = coolant cond = heat conduction conv = heat convection F = film HG = hot gas p = at constant pressure r = recovery rad = radiation res = reservoir S = surface x, y = coordinates W = wall 0 = plenum ∞ = ambient

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Section: In-flight Measurementmentioning

confidence: 99%

Section: Flight Experiments Setup and Instrumentationmentioning

confidence: 99%

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Transpiration-Cooled Hypersonic Flight Experiment: Setup, Flight Measurement, and Reconstruction

Böhrk

2015

Journal of Spacecraft and Rockets

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“…The TPS panels are supported in all directions by a central post and flexible stand-offs at the four corners, so that the panel's thermal expansion is not suppressed [11]. The aluminum substructure carries the in-flight measurement infrastructure such as thermocouple compensation, pressure transducers, and other sensors [2].…”

Section: Flight Experiments Set-up and Instrumentationmentioning

confidence: 99%

“…In order to interpret the cooling effect of the transpiration, AKTiV is instrumented with thermocouples, as well as pressure sensors and resistance thermometers [2]. The experiment, using a porous and permeable C/C ceramic, is located on a panel of row C, as shown in fig.…”

Section: Introductionmentioning

confidence: 99%

Transpiration Cooling at Hypersonic Flight - AKTiV on SHEFEX II

Böhrk

2014

11th AIAA/ASME Joint Thermophysics and Heat Transfer Conference

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The present paper presents the in-flight measurement of the transpiration cooling experiment AKTiV flown on the sub-orbital re-entry configuration SHEFEX II. Thermal response of the structure is measured just up-and downstream of a cooled sample with a non-cooled reference set-up on the opposite side of the vehicle. The measurement shows that the heat flux is reduced upon coolant exhaust. The maximum temperature reduction by transpiration-cooling is observed on the porous sample with 87 K, while downstream the sample, the temperature reduction by film cooling is 75 K. This corresponds to cooling efficiencies of 61% and 46% on the sample and downstream, respectively. The evaluation is supported by the semi-analytical tool HEATS, based on a transient heat balance at the surface. Comparison of the results with HEATS shows that the heat flux predicted with HEATS is in good concurrence with the measured temperatures on the cooled sample, as well as upstream and downstream with a maximum deviation by 14%. The analysis shows that the flow condition around the sharp-edged, faceted vehicle remains longer laminar than expected.

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Combined Instrumentation Package COMARS+ for the ExoMars Schiaparelli Lander

et al. 2017

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In order to measure aerothermal parameters on the back cover of the ExoMars Schiaparelli lander the instrumentation package COMARS+ was developed by DLR. Consisting of three combined aerothermal sensors, one broadband radiometer sensor and an electronic box the payload provides important data for future missions. The aerothermal sensors called COMARS combine four discrete sensors measuring static pressure, total heat flux, temperature and radiative heat flux at two specific spectral bands. The infrared radiation in a broadband spectral range is measured by the separate broadband radiometer sensor. The electronic on the ExoMars back cover radiation tests were carried out to verify their radiation hardness. Finally the bioburden reduction process was demonstrated on the qualification hardware to show the compliance with the planetary protection requirements. To test the actual heat flux, pressure and infrared radiation measurement under representative conditions, aerothermal tests were performed in an arc-heated wind tunnel facility. After all qualification tests were passed successfully, the acceptance test campaign for the flight hardware at acceptance level included the same tests than the qualification campaign except shock, radiation hardness and aerothermal tests. After passing all acceptance tests, the COMARS+ flight hardware was integrated into the Schiaparelli capsule in January 2015 at the ExoMars integration site at Thales Alenia Space in Turin. Although the landing of Schiaparelli failed, resulting in the loss of most COMARS+ flight data because they were stored on the lander, some data points were directly transmitted to the orbiter at low sampling rate during the entry phase. These data indicate that all COMARS+ sensors delivered useful data until parachute deployment with the exception of the plasma blackout phase. Since measured structure and sensor housing temperatures are far below predicted preflight values, a new calibration using COMARS+ spare sensors at temperatures below 0° C is necessary. Therefore no flight data is presented in this paper.

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Sharp Edge Flight Experiment-II Instrumentation Challenges and Selected Flight Data

Cited by 22 publications

References 20 publications

Transpiration-Cooled Hypersonic Flight Experiment: Setup, Flight Measurement, and Reconstruction

Transpiration-Cooled Hypersonic Flight Experiment: Setup, Flight Measurement, and Reconstruction

Transpiration Cooling at Hypersonic Flight - AKTiV on SHEFEX II

Combined Instrumentation Package COMARS+ for the ExoMars Schiaparelli Lander

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