Future science and technology for military space

Fuhs, Allen E.

doi:10.2514/6.1990-3827

Cited by 5 publications

(5 citation statements)

References 2 publications

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“…The mixing and transport processes of the chemical species resulting from combustion were modeled by solving conservation equations for the local mass fractions of each species, as shown in Eq. (7). In this equation, Eq.…”

Section: Compressible Reacting Flow Modelmentioning

confidence: 99%

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Simulation of Plasma Assisted Supersonic Combustion over a Flat Wall

Gutierrez¹,

Álvarez²

2022

MMEP

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This work presents a simplified methodology to couple the physics of a nanosecond pulsed discharge to the process of supersonic combustion in a flat wall combustor configuration. Plasma and supersonic combustion are separately simulated and then coupled by seeding plasma-generated radicals on the combustion domain. The plasma model is built assuming spatial uniformity and considering only the kinetic effects of the nanosecond pulsed discharge. Therefore, a zero-dimensional kinetic scheme accounting for the generation of plasma species is utilized. For the combustion model, the complete set of Favre-averaged compressible Navier Stokes equations along with finite rate chemistry is solved through a control-volume based technique via the commercial software Ansys Fluent. The computational results are compared against experimental studies showing that the proposed methodology can capture the main kinetic effects of the nanosecond pulsed discharge on supersonic combustion. OH concentration contours reveal the presence of an enhanced flame when the plasma is applied following the trends from experimental OH PLIF images. In addition, time evolving temperature and OH concentration contours show that the ignition delay time is reduced with the application of the discharge.

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Section: Compressible Reacting Flow Modelmentioning

confidence: 99%

“…Over the last decades, there have been an increasing interest in hypersonic vehicles due to their capability in enabling low-Earth orbit flights and defense and transport applications [1][2][3][4][5][6][7]. The scramjet engine is a candidate for this type of applications.…”

Section: Introductionmentioning

confidence: 99%

Simulation of Plasma Assisted Supersonic Combustion over a Flat Wall

Gutierrez¹,

Álvarez²

2022

MMEP

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“…The positron annihilates with an accompanying electron, yielding two gamma ray photons on the scale of 1.02 MeV [11][12][13]. The positron was discovered in 1936 [14]. The antiproton annihilates with a proton yielding pions.…”

Section: Previous Antimatter Propulsion Architecturesmentioning

confidence: 99%

Fundamental Architecture and Analysis of an Antimatter Ultra-Intense Laser Derived Pulsed Space Propulsion System

Moyne¹,

Mastroianni²

2014

JAMP

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Antimatter has been generated in large quantities by the Lawrence Livermore National Laboratory Titan laser. The Titan laser is an ultra-intense laser system on the order of approximately 10 20 W/cm 2 with pulse durations of roughly 1ps. With the Titan laser incident on a high atomic number target, such as gold, antimatter on the scale of 2 × 10 10 positrons are generated. Roughly 90% of the generated positrons are ejected anisotropic and aft to the respective target. The mechanisms for the laser-derived positron antimatter generation involve electron interaction with the nuclei based on bremsstrahlung photons that yield electron-positron pairs as a consequence of the Bethe-Heitler process, which predominates the Trident process. Given the constraints of the current and near future technology space, a pulsed space propulsion configuration is advocated for antimatter derived space propulsion, similar in concept to pulsed radioisotope propulsion. Antimatter is generated through an ultra-intense laser on the scale of a Titan laser incident on a gold target and annihilated in a closed chamber, representative of a combustion chamber. Upon reaching a temperature threshold, the closed chamber opens, producing a pulse of thrust. The implication of the pulsed space propulsion antimatter architecture is that the energy source for the antimatter propulsion system can be decoupled from the actual spacecraft. In contrast to conventional chemical propulsion systems, which require storage of its respective propulsive chemical potential energy, the proposed antimatter propulsion architecture may have the energy source at a disparate location from the spacecraft. The ultra-intense laser could convey its laser energy over a distance to the actual spacecraft equipped with the positron antimatter pulsed space propulsion system. Hydrogen is considered as the propulsive fluid, in light of its low molecular weight. Fundamental analysis is applied to preliminarily define the performance of the positron antimatter derived pulsed space propulsion system. The fundamental performance analysis of the antimatter pulsed space propulsion system successfully reveals the architecture is viable for further evaluation.

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“…The hypersonic platform SAR mainly works in the near space and the typical altitude is 20–100 km, which helps to obtain a wider range of observations compared with the conventional airborne platform SAR [1]. Meanwhile, the high‐speed cruise and flexible manoeuvring characteristics of this platform can reduce the revisit time, thus continuously monitor the focus area [2, 3]. In addition, the flight path of this platform is planned as a curved trajectory to avoid the tracking and interception of the hostile weapon system, thus an arc band‐shaped coverage could be illuminated [4].…”

Section: Introductionmentioning

confidence: 99%