Experimental Verification of Heat-Flux Mitigation by Electromagnetic Fields in Partially-Ionized-Argon Flows

Gülhan, Ali; Esser, Burkard; Koch, Uwe; Siebe, Frank; Riehmer, Johannes; Giordano, D.; Konigorski, Detlev

doi:10.2514/1.39256

Cited by 79 publications

(37 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It has also been shown that the surface conductivity of the probe body influences the magnetic field effects, since surface currents can short out the magnetically induced electric fields. The observed increase in bow shock distance can lead to a decrease of heat flux, with mitigation of up to 85% already having been observed 10) . However, the decrease of the integral heat flux is not the only important quantity.…”

Section: Introductionmentioning

confidence: 78%

Comparison of Plasma Magnetic Field Interactions in a Static and Dynamic Plasma Facility

Dropmann

Knapp

Eichhorn

et al. 2016

AEROSPACE TECHNOLOGY JAPAN

View full text Add to dashboard Cite

In space technology many concepts for magnetic fields are under discussion for the use in advanced propulsion, shielding from radiation or as aid for thermal protection system for the atmospheric entry of spacecraft. Two experiments have been conducted to investigate the feasibility of using magnetic fields to reduce the heat flux onto a thermal protection system during atmospheric entry. For this purpose a modified heat flux probe with embedded permanent magnets has been exposed to a plasma jet and the structure of the bow shock in front of the probe has been observed using an emission spectroscopy setup. The intensity ratio of ionized argon lines for the experiment with and without magnets has been determined and used to analyze the magnetic field`s impact on the flow. Complementary experiments in a low power capacitively driven plasma have been conducted using micron sized particles as probes to map electric fields in a magnetically perturbed plasma. The results from both experiments are presented and analogies are drawn from both approaches. The experiments have shown that the interactions of the magnetic field with the plasma can create strong electric fields which strongly influence the ions even though the field is too weak to magnetize the ions.

show abstract

Section: Introductionmentioning

confidence: 78%

Comparison of Plasma Magnetic Field Interactions in a Static and Dynamic Plasma Facility

Dropmann

Knapp

Eichhorn

et al. 2016

AEROSPACE TECHNOLOGY JAPAN

View full text Add to dashboard Cite

show abstract

“…For a summary of emission spectroscopy results, see [7,8]. Laser Induced Fluorescence Spectroscopy (LIF) on NO molecules seeded to the Argon has been used to determine the rotational temperature and concentration within the free stream and the bow shock layer [9,10].…”

Section: Flow Characterization Methodsmentioning

confidence: 99%

“…Concerning the temperature measurement, the broadening of the signal due to the shear layer leads to increased temperature values. As no quantitative information about the divergence of the §ow vectors and the thickness of the shear layer is available, the presented data should be used for a qualitative interpretation of the §ow properties [10]. The determined §ow velocity and the translational temperature of all studied §ow conditions are listed in Table 1 and discussed in section 4.…”

Section: Diode Laser Absorption Spectroscopymentioning

confidence: 99%

Characterization of weakly ionized argon flows for radio blackout mitigation experiments

Steffens

Koch

Esser

et al. 2017

Progress in Flight Physics

View full text Add to dashboard Cite

For reproducing the so-called E × B communication blackout mitigation scheme inside the L2K arc heated facility of the DLR in weakly ionized argon §ows, a §at plate model has been equipped with a superconducting magnet, electrodes, and a setup comprising microwave plasma transmission spectroscopy (MPTS). A thorough characterization of the weakly ionized argon §ow has been performed including the use of microwave interferometry (MWI), Langmuir probe measurements, Pitot probe pro¦les, and spectroscopic methods like diode laser absorption spectroscopy (DLAS) and emission spectroscopy.

show abstract

“…The expected MHD effects are to increase the bow shock distance and, as a consequence, possibly reduce the heat flux onto the probe body. These influences are currently analyzed experimentally and numerically by several research groups all over the world [2][3][4][5][6][7][8]. An excellent review of the work done within this field since the 1970s is given in references [6] and [8].…”

Section: Introductionmentioning

confidence: 99%

“…The results of this experimental and numerical analysis will be compared, and discussed with respect to similar research activities [6,13] …”

Section: Introductionmentioning

confidence: 99%

Investigation of MHD Impact on Argon Plasma Flows by Variation of Magnetic Flux Density

Knapp¹

2012

TOPPJ

View full text Add to dashboard Cite

Abstract:The interaction between a probe body and argon plasma flow is investigated to examine to what extent the probe head temperature and the bow shock distance can be influenced by applying a strong magnetic field. The experiments are performed using a strong permanent magnet installed inside a probe body with a spherical, coated probe head. Former investigations showed strong influence on the bow shock geometry but also on the inflow plasma jet. Several boundary conditions have been varied to evaluate their influence on the experiment. For an uncoated probe head the measured MHD impact was found to be of the same order of magnitude as for the coated case. Electrical isolation of the probe toward the vacuum chamber yielded only slight influence. The variation of the field strength was achieved by changing the amount of magnet segments installed. Pictures were analyzed to document the MHD interaction for each test case. It was found that the bow shock distance increased and the temperature of the probe head decreased while increasing the magnetic field density. This analysis precedes a thorough characterization of the plasma condition.

show abstract

Experimental Verification of Heat-Flux Mitigation by Electromagnetic Fields in Partially-Ionized-Argon Flows

Cited by 79 publications

References 23 publications

Comparison of Plasma Magnetic Field Interactions in a Static and Dynamic Plasma Facility

Comparison of Plasma Magnetic Field Interactions in a Static and Dynamic Plasma Facility

Characterization of weakly ionized argon flows for radio blackout mitigation experiments

Investigation of MHD Impact on Argon Plasma Flows by Variation of Magnetic Flux Density

Contact Info

Product

Resources

About