Ядренкин М.А.   Fomichev V.P.  

Strong MHD-intraction in hypersonic flows near bodies

Reporter: Ядренкин М.А.

Magnetohydrodynamic (MHD) interaction in high-speed gas flows allows one to vary the flow near bodies. This approach can be used to change the aerodynamic characteristics of prospective hypersonic aircraft, as well as in the channel of scramjet.

In previous studies, a local MHD interaction was revealed on the surface of the model during ionization of the hypersonic air flow by an electric discharge. At the same time Ampere's force was directed towards the incoming flow and caused its local braking. It was shown that when the parameter of the hydromagnetic interaction increases, the attrached shock wave generated by the leading edge is transformed into a bow shock in front of the model. Under the experimental conditions, three modes of MHD interaction were observed (weak, moderate and strong), which corresponded to the hydromagnetic interaction values S <0.05, S = 0.05-0.15 and S> 0.15 [1]. There are practically no observed the effect on the shock-wave flows structure at the weak MHD interaction. Moderate interaction is characterized by the fact that the magnitude of the force is sufficient to maintain a stable ionization zone at the model surfaces. In this case, the angle of attached shock wave generated by the leading edge or the shock generated in the interaction region increases. A strong MHD interaction in the flow is characterized by the fact that a bow shock wave forms before the region of the braked flow.

The process of formation of the head jump before the MHD interaction zone was also observed in experimental studies of the interaction on the surface of the model of the reentry vehicles during gas ionization by a pulsed electric discharge [2], and also in studies of the interaction of a gas discharge with an incoming flow in a magnetic field without a model [3]. All investigations were carried out at the same flow and discharge parameters. For each case, the parameter of the hydromagnetic interaction was calculated, which turned out to correspond to the value of the parameter S for a strong MHD interaction.

Thus, for a strong MHD interaction, the shape of the model has little effect on the final result of the change in the flow pattern, since the size of the interaction region becomes comparable, and in some cases larger than the size of the streamlined body.

REFERENCES

  1. Fomichev V.P., Yadrenkin M.A., Shipko E.K. Effect of volumetric electromagnetic forces on shock wave structure of hypersonic air flow near plate // 18th International Conference on the Methods of Aerophysical Research (ICMAR2016) (Russia, Perm, 27 Jun.-3 Jul., 2016) : AIP Conference Proceedings. -Vol.1770. -S.l., 2016. -P. 030068. DOI: 10.1063/1.4964010
  2. V.P. Fomichev, M.A. Yadrenkin, Experimental investigation of MHD interaction in front of the reentry model in hypersonic air flow // Abstracts: XI Russian Conference of Young Scientists "Problems of Mechanics: Theorretic, Experiment and New Technologies", Novosibirsk, March 17, 20-23 2017, p.
  3. M.A. Yadrenkin, V.P. Fomichev. Ionization of a hypersonic air flow by electrical discharges in a magnetic field // Int. Conf. on the Methods of Aerophys. Research: Abstracts. Pt. II. Novosibirsk, 2014. P. 215-216.


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