Decoy systems simulating jet aircraft plume emissions and strategies for suppression of emissions from missile plumes

Lombard, Johan Francois (1997-03)

Thesis (PhD) -- University of Stellenbosch, 1997.

Thesis

ENGLISH ABSTRACT: This study covers the development of technology to be able to manufacture a flare that can lure a modem state-of-the-art heat-seeking missile. Consequently it was necessary to characterize the exhaust plumes of certain fighter aircraft. This characterization involved the spectral analyses of the aircraft plume emission over the entire infrared region. The important influence that shock heating of C02 and N2 in the Mach discs of the plume has on theinfrared spectral emission, has been realised. Since shock heating is absent in normal flare designs, the effect of shock heating was simulated by chemical manipulations of the flare composition. This resulted in a flare which simulated the infrared emission spectrum of a jet aircraft plume. The inadequacy of the existing operational flare has been demonstrated by spectral analysis. It has also been established that the pyrotechnical composition of this flare is such that it cannot be manipulated to successfully simulate an aircraft plume. Secondly, the plumes of rocket motors were characterized. The propellant samples of these motors were specially selected to be representative of currently used and nearly qualified propulsion systems. This study not only involved the infrared and ultraviolet emissions of the plumes, but also at 30Hz in the RADAR region regarding transmission and RADAR cross-section measurements. The results of this study can be applied in the stealth environments of modem rockets and missiles. This technology can also be used in an in-flight identifying (friend or foe) role with respect to aircraft and missiles.

AFRIKAANSE OPSOMMING: Hierdie studie behels die d~stelling van tegnologie wat dit moontlik maak om 'n fakkel te vervaardig wat oor die vermoe beskik om 'n modeme hittegeleide missiel te kan mislei. Dit was gevolglik nodig om die pluime van sekere vegvliegtuie te karakteriseer. Hierdie karakterisering behels die spektraalanaliese van die vliegtuigpluimemissie en strek oor die hele infrarooi gebied van die spektrum. Die skokverhitting van CO2 en N2 in die Machskywe van 'n vliegtuigpluim speel 'n belangrike rol tydens die spektrale infrarooi emissie. Hierdie aspek is egter vroeg besef. Aangesien skokverhitting, en dus ook die effek daarvan in die pluim, afwesig is tydens nomale fakkelontbranding, was dit genoodsaak om die effek deur chemiese manipulasie te simuleer. Deur die emissiespektrum van die huidige operasionele fakkel te analiseer kon die onvermoe daarvan vasgestel word. Dit was ook bepaal dat, weens die chemiese samestelling van die fakkel, dit nie moontlik is vir hierdie fakkel om 'n vliegtuigpluim suksesvol te simuleer nie. Ten tweede was die pluime van vuurpylmotors ook gekarakteriseer. Die samestelling van die dryfmiddelkeuse was sodanig dat dit goed verteenwoordigend is van dryfmiddels reeds in gebruik asook in byna gekwalifiseerde stelsels. Tydens hierdie ondersoek was daar nie net gekyk na die infrarooi en ultraviolet emissies nie, maar ook na die 3GHz radargebied. Daar is uitsluitlik gekonsentreer op die radardeursnit en die radardeurlating van pluime. Die resultate wat verkry is kan aangewend word in die sluipomgewing van modeme vuurpyle en missiele, veral rakende die aandrywingstelsels. Hierdie tegnologie kan ook uitgebou en verder ontwikkel word om in vlug identifikasie (vriend ofvyand) van vliegtuie en missiele te kan doen.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/49652
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