Blunt body wave drag reduction using focused energy deposition

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

doi:10.2514/6.1998-1647

Cited by 20 publications

(13 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This temporal error growth rate can now quantitatively be compared to the prediction maxðReðkÞÞ of the stability theory, which gives the theoretical temporal error growth rate of the most unstable mode according to Eq. (11). When the errors become sufficiently large, nonlinear effects play a role and lead away from exponential growth which can be observed in Fig.…”

Section: Resultsmentioning

confidence: 87%

“…Other experiments involving various forms of the bow shock perturbation have shown carbuncle-like pulsating flows. These perturbations include: the injection of a forward-facing jet along the stagnation line [7][8][9], the injection of dust particles along the stagnation line [10], the energy deposition ahead of the bow shock [11][12][13]. In many cases, the perturbation yields a pulsating flow which oscillates between the regular detached bow shock and a carbuncle-like shock pattern.…”

Section: A Physical Instability?mentioning

confidence: 99%

See 1 more Smart Citation

A matrix stability analysis of the carbuncle phenomenon

Dumbser¹,

Moschetta²,

Gressier³

2004

Journal of Computational Physics

160

108

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 87%

Section: A Physical Instability?mentioning

confidence: 99%

A matrix stability analysis of the carbuncle phenomenon

Dumbser¹,

Moschetta²,

Gressier³

2004

Journal of Computational Physics

160

108

View full text Add to dashboard Cite

“…1 3 An unspeci ed focused energy deposition upstream of a vehicle has also been analyzed for improving aerodynamic performance. 4 A common feature of these reports is the interaction of the oncoming stream with the introduced ow eld perturbation.As a consequence of the ow eld adjustment to either the counter ow jet or a locally released thermal energy source, favorable ow control can be realized. These particular ow control mechanisms are completely independent of electromagnetic forces.…”

mentioning

confidence: 98%

Jet-Spike Bifurcation in High-Speed Flows

et al. 2001

View full text Add to dashboard Cite

In recent plasma injection experiments, counter ow jet interaction has been identi ed as one of the mechanisms that signi cantly reduces the drag. There is a sudden change of the dynamic state from an oscillatory to nearly steady motion of this jet-shock interaction which depends on the relative magnitude of injection and the stagnation pressure. The shock-wavebifurcation associated with a counter ow jet from a hemispherical cylinder is investigated by a side-by-side experimental and computationaleffort. Shock-wave bifurcation has been discovered by the present experiments over the entire range of tested conditionsin the Mach 6 wind tunnel. This oscillatory motionis sustained by the upstream propagationof selectively ampli ed frequencies from the free-shear layer to the Mach disk through the embedded subsonic domain. The breakdown of this feedback loop occurs when a higher injecting jet pressure creates a supersonic zone separating the interconnecting embedded subsonic domains. Nomenclature D = total drag p = air pressure Q = conservative variables q = primitive variable r = radius of hemispheric nose T = air temperature u = velocity vector, u, v, w D = standoff distance of bow shock q = air density

show abstract

“…Other approaches to the wave drag reduction are to use the focused energy deposition. A wide variety of energy deposition techniques were investigated by laser pulse, plasma arcs, microwaves, electron beams, pulsed detonations or explosions, etc [16][17][18][19][20][21] . When the focused energy is deposited in the upstream region of a blunt body, the extremely hot gas is created instantaneously to push the surrounding gas outward 17 .…”

Section: American Institute Of Aeronautics and Astronauticsmentioning

confidence: 99%

Conceptual study on non-ablative TPS for hypersonic vehicles

Jiang

Liu²,

Han³

2011

17th AIAA International Space Planes and Hypersonic Systems and Technologies Conference

View full text Add to dashboard Cite

In order to achieve efficient wave drag reduction under non-zero attack angles and avoid the severe aerodynamic heating, a new concept of the Non-ablative Thermal Protection System (NaTPS) for hypersonic vehicles was proposed based on the idea that the conical shock wave angle can be enlarged by lateral jets to push the conical shock away from the blunt body surface. In the NaTPS, a spike-blunt body structure and lateral jets are combined together to develop a new shock-reconstructing system in front of hypersonic vehicles. When the spike acts to recast the bow shock in front of a blunt body into a conical shock, the lateral jet works to protect the spike tip from overheating and push the conical shock away from the blunt body when a pitching angle exists during flight. The experimental flow visualization and the pressure measurements were conducted in a hypersonic wind tunnel for both the conceptual demonstration and CFD validation. Numerical simulations were also carried out to examine the complex flow around the NaTPS. Both experimental and numerical results show that the NaTPS works well for shock drag reduction and thermal protection. The shock/shock interaction on shoulders of the blunt body is avoided due to lateral jet injection and the peak pressure at the reattachment region is reduced by 65% under a 4• attack angle. The lateral jet could be powered either by high pressure gas stored in the tank or by the water evaporation process in which water absorbs the heat from the hot walls of the blunt noses. The jet pressure needed for producing lateral jet is much smaller than for the forward-facing jet from the stagnation point. The advantages of this concept are well demonstrated and its practical application appears promising. Nomenclature

show abstract

Blunt body wave drag reduction using focused energy deposition

Cited by 20 publications

References 4 publications

A matrix stability analysis of the carbuncle phenomenon

A matrix stability analysis of the carbuncle phenomenon

Jet-Spike Bifurcation in High-Speed Flows

Conceptual study on non-ablative TPS for hypersonic vehicles

Contact Info

Product

Resources

About