Blunt-Body Wave Drag Reduction Using Focused Energy Deposition

Riggins, David W.; Nelson, H. F.; Johnson, E.

doi:10.2514/2.756

Cited by 176 publications

(39 citation statements)

References 7 publications

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“…That is because the decrease of the plasma density is sure to lead to the decrease of the inductance according to Eq. (6). So, it is quite natural that the resonant permittivity which is required to match the inductance decreases with the plasma density.…”

Section: Parameter Analysismentioning

confidence: 99%

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A matching approach to communicate through the plasma sheath surrounding a hypersonic vehicle

Gao

Jiang

2015

Journal of Applied Physics

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A matching approach to communicate through the plasma sheath surrounding a hypersonic vehicle In order to overcome the communication blackout problem suffered by hypersonic vehicles, a matching approach has been proposed for the first time in this paper. It utilizes a double-positive (DPS) material layer surrounding a hypersonic vehicle antenna to match with the plasma sheath enclosing the vehicle. Analytical analysis and numerical results indicate a resonance between the matched layer and the plasma sheath will be formed to mitigate the blackout problem in some conditions. The calculated results present a perfect radiated performance of the antenna, when the match is exactly built between these two layers. The effects of the parameters of the plasma sheath have been researched by numerical methods. Based on these results, the proposed approach is easier to realize and more flexible to the varying radiated conditions in hypersonic flight comparing with other methods. V C 2015 AIP Publishing LLC. [http://dx.

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Section: Parameter Analysismentioning

confidence: 99%

“…[3][4][5] Therefore, choosing an appropriate shape can mitigate communication blackout. However, in some cases, sharp-nosed body cannot be applied, because blunt-nosed body can provide hypersonic cruise vehicles with a desirable thermal protection performance 6 and help reentry vehicles slow down as quickly as possible. Magnetic windows is another approach.…”

mentioning

confidence: 99%

A matching approach to communicate through the plasma sheath surrounding a hypersonic vehicle

Gao

Jiang

2015

Journal of Applied Physics

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“…Thermal energy deposition in front of a flying body to perturb the incoming flow and shock wave formation has been studied [3] [4] [5] [6] [7]. The heating of the gas in front of a flying body essentially reduces the Mach number of the incoming flow in the heated region.…”

Section: Introductionmentioning

confidence: 99%

Shock Wave Mitigation by Air Plasma Deflector

Kuo¹

2018

AAST

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When the spacecraft flies much faster than the sound speed (~1200 km/h), the airflow disturbances deflected forward from the spacecraft cannot get away from the spacecraft and form a shock wave in front of it. Shock waves have been a detriment for the development of supersonic aircrafts, which have to overcome high wave drag and surface heating from additional friction. Shock wave also produces sonic booms. The noise issue raises environmental concerns, which have precluded routine supersonic flight over land. Therefore, mitigation of shock wave is essential to advance the development of supersonic aircrafts. A plasma mitigation technique is studied. A theory is presented to show that shock wave structure can be modified via flow deflection. Symmetrical deflection evades the need of exchanging the transverse momentum between the flow and the deflector. The analysis shows that the plasma generated in front of the model can effectively deflect the incoming flow. A non-thermal air plasma, generated by on-board 60 Hz periodic electric arc discharge in front of a wind tunnel model, was applied as a plasma deflector for shock wave mitigation technique. The experiment was conducted in a Mach 2.5 wind tunnel. The results show that the air plasma was generated symmetrically in front of the wind tunnel model. With increasing discharge intensity, the plasma deflector transforms the shock from a welldefined attached shock into a highly curved shock structure with increasing standoff distance from the model; this curved shock has increased shock angle and also appears in increasingly diffused form. In the decay of the discharge intensity, the shock front is first transformed back to a well-defined curve shock, which moves downstream to become a perturbed oblique shock; the baseline shock front then reappears as the discharge is reduced to low level again. The experimental observations confirm the theory. The steady of the incoming flow during the discharge cycle is manifested by the repeat of the baseline shock front.

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“…A number of numerical calculations have been performed recently of supersonic flow past the region of energy release [4][5][6][7] and of flow past bodies of different shapes in the presence of a source of energy preceding these bodies and of drag reduction [8][9][10][11][12][13]. Experiments were also performed with laser [14] and microwave pulses and discharges for initiating energy release, as a rule, at low values of Mach number and average power.…”

Section: Introductionmentioning

confidence: 99%

Reduction of drag and energy consumption during energy release preceding a blunt body in supersonic flow

et al. 2004

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A simple approximate theory is used to estimate the optimal power of a stationary lumped source of energy in a supersonic flow and its minimal distance from a body, which provide for a significant reduction of energy consumption required for the advance of the body. Similarity laws are formulated for the conversion of the numerical or experimental results to other conditions. Numerical simulation is performed of the incidence of hypersonic flow on a blunt body with and without energy release. The calculations are performed in application to the described new experiments in flow past a model and in measuring the drag in a hypersonic shock tunnel at Mach 10 in the presence or absence of a powerful arc source of energy. Descriptive patterns are given of flow and space distributions of gasdynamic quantities. The calculated shapes of waves agree well with schlieren photographs, and the calculated value of drag force -with the measured value. It is demonstrated numerically that, under close-to-optimal conditions, the drag may be reduced by a factor of approximately five, and the total energy consumption required to overcome this drag -by a factor of four.

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Blunt-Body Wave Drag Reduction Using Focused Energy Deposition

Cited by 176 publications

References 7 publications

A matching approach to communicate through the plasma sheath surrounding a hypersonic vehicle

A matching approach to communicate through the plasma sheath surrounding a hypersonic vehicle

Shock Wave Mitigation by Air Plasma Deflector

Reduction of drag and energy consumption during energy release preceding a blunt body in supersonic flow

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