DIRD_33-DIRD_MHD_Air_Breathing_Propulsion_and_Power_for_Aerospace_Applications.pdf

UNCLASSIFIED / / P@-05FiGhr=USE-Oiieye Defense Intelligence Reference Document fo Defense Futures 21 November 2010 ICOD: 20 July 2010 DIA-08-1011-006 MHD Air Breathing Propulsion and Power for Aerospace Applications UNCLASSIFIED / / POR°OPFICTAL USE ONLY

UNCLASSIFIED / / P@ie-GFPtChrEUSE-OnEE MHD Air Breathing Propulsion and Power for Aerospace Applications The Defense Intelligence Reference Document provides nonsubstantive but authoritative reference information related to intelligence topics or methodologies. Prepared by: (b)(3):10 USC 424 Defense Intelligence Agency Authors: (b)(6) (U} COPYRIGHT WARNING: Further dissemination of the photographs in this publication is not authorized. This product is one of a series of advanced technology reports produced in FY 2010 under the Defense Intelligence Agency, [(p)\(3):10 USC 424 Advanced Aerospace…

UNCLASSIFIED / POROPS?tCGh-USEOhle— Contents SUMMARY .uccceneeeeceesssauscueeeceneeeeeceenueuseeseeeaeneanenuneeaneeeaeeeneneeneene seuuseeesaaeer iv Chapter 1: CONCEPT OVERVIEW ......ccccssccssscecnecessnsncecencuensnsseeassenauaseeuses 1 Weakly Ionized Plasmas for Propulsion Applications. .........ccsscscseenee 2 Electric Propulsion Systems POET TTTTTTTTTTTELETT TTT TT ere reeeeeeLeee Terre errr er rrriry is, Chapter 2: AERONAUTICAL APPLICATIONS. .....scscscaseceeescsenercneusussessenans ii Basic Principles of Magnetohydrodynamics and Requirements for MHD PerformannCe .......cececeseecseeeen…

UNCLASSIFIED / APO@R"OPPPCR=USE-ONEG= MHD Air-Breathing Propulsion and Power for Aerospace Applications Summary The paper reviews novel propulsion concepts utilizing plasmas (ionized gases) and magnetohydrodynamics (MHD). These concepts are shown to be attractive due to their potential to achieve propulsion and aerodynamic performance far beyond current conventional technologies. However, significant difficulties impede the development and application of these technologies; these include weight, complexity, higher power, and the need for complex and energy-consuming artificial ionization in “c…

UNCLASSIFIED / /S02-95FtGEAE-USEOntT Chapter 1: Concept Overview A flight vehicle's speed and altitude limit its available propulsion options. Traditional air-breathing systems (propeller, turbofan, and turbojet) are typically limited to altitudes below 80,000 feet. The existing and planned high-altitude vehicles utilize either high-speed propulsion with ramjet and scramjet engines or slow-speed systems with large propellers. Chemical rockets can operate at all altitudes but have limited burn times and require both fuel and oxidizer to be carried onboard. High-speed air-breathing propulsion, b…

UNCLASSIFIED / A2@2-GEELGRinUGE-GAS electric (plasma) thrusters have been around for decades, their use in space was limited by the electric power available onboard the spacecraft.2 The advent of high-power solar arrays has made systems from a few kW to tens of kW practical. Chemical systems will probably always be the primary choice for getting vehicles into space. The thrust levels for electric systems are too low to be practical! for that purpose. Chemical and electric (or electromagnetic) propulsion systems have intrinsic differences. For example, chemical propulsion is “energy limited” be…

UNCLASSIFIED / -P@@"@EE5GHMi-WS Ghia and in devices such as the gliding arc, the plasma evalves from néar-equilibrium to highly nonequilibrium during each of the periodically repeating cycles. In shock and boundary layers during reentry, the plasma is near thermal equilibrium while being diffuse. The primary reason for this behavior is that the ionization in those shock and boundary layers exists without any electric field and thus is not subject to arcing instabilities. Plasma Features What features or properties make weakly ionized plasmas interesting for propulsion and aerodynamic applicati…

UNCLASSIFIED / /®@R-@EEDGhE UGE ONE ram/scramjet combustors if alkali vapor is added to the gas. In those regions, MHD interactions can be promising for electric power generation or acceleration of the flow, as well as for flow control. However, at Mach numbers below about 12 (and excluding the combustor or the region just downstream of it), the air is too cold for a significant thermal ionization even with alkali seeding. The required level of ionization then has to be created and sustained by nonequilibrium (nonthermal) means and is associated with a very substantial power budget and additio…