Combustion Mechanism of Double‐Base Propellants with lead burning rate catalysts

Lead-based compounds are the current industrystandard ballistic modifier for double-base propellants, but there is a pressing need for alternatives as incoming European legislation will soon ban their use. This review article introduces the main concepts and terminologies in the combustion chemistry of double-base propellants, and critically evaluates the four theories put forward in the literature to account for the ballistic modifier effect, namely (i) photochemical, (ii) chelating/complex, (iii) carbon soot, and (iv) free radical theories. We also review the literature on current trends in ballistic modifier research and note the emerging potential of oxide nanoparticles (in particular Bi 2 WO 6) and Cu/Bi encapsulated in carbon nanotubes as lead-free ballistic modifier additives.

true N O + 2 C_{s u r f a c e} \to C_{s u r f a c e} ((), N) + C_{s u r f a c e} ((), O)

true C_{s u r f a c e} ((), O) \to C O

true 2 C_{s u r f a c e} ((), N) \to 2 C_{s u r f a c e} + N_{2}

…”

Section: Combustion Reactions and The Five Combustion Zonessupporting

confidence: 84%

Section: Combustion Reactions and The Five Combustion Zonesmentioning

confidence: 99%

Section: Combustion Reactions and The Five Combustion Zonesmentioning

confidence: 99%

“…After the formation of carbon deposits, Youfang [36] postulated that PbO presents a secondary process in the combustion of carbon:

true P b O + C \to P b + C O

true P b O + C O \to P b + C O_{2}

…”

Section: Combustion Reactions and The Five Combustion Zonesmentioning

confidence: 99%

true C / N O > 1, s u p e r - r a t e b u r n i n g

true C / N O \approx 1, p l a t e a u e f f e c t

true C / N O < 1, m e s a e f f e c t

…”

Section: Combustion Reactions and The Five Combustion Zonesmentioning

confidence: 99%

See 3 more Smart Citations

A Review of the Catalytic Effects of Lead‐Based Ballistic Modifiers on the Combustion Chemistry of Double Base Propellants

Warren

Zi-Xuan

Pulham

et al. 2020

Influence of carbon on combustion characteristics of Magnesium‐Sodium Nitrate Propellant

Singh

Somayajulu

Rao

et al. 1991

Effect of addition of carbon in the form of graphite and carbolac on the combustion characteristics of Magnesium‐Sodium nitrate propellant has been studied. Results indicated that the burning rate of the propellant increased significantly by the addition of graphite upto 2%. Thermal decomposition studies revealed that the graphite particles in addition to its absorption of thermal energy being an inert material react with the decomposed products of the sodium nitrate just above the burning surface of the propellant for the exothermic heat release. This heat release which is high at low concentration of graphite is seen causing high burning rate. Any further increase in graphite concentration beyound 2% reduces the burning rate as the thermal energy absorption exceeds the heat release at the burning surface. When carbon in the form of carbolac was used in the composition reactive species diffuse out prior to the sample ignition without participating in the combustion thus reduces the burning rate. The heat of reaction data supported the suggested mechanism.

The energy and pressure exponent of composite modified double‐base propellant

Zhulin

Feng

Enpu

et al. 1992

Energiegehalt und Druckexponent bei modifizierten Komposit-Doublebase-TreibstoffenIn der vorliegenden Arbeit wird eine Analyse des Energiegehalts und des Druckexponentenverlaufs bei modifizierten Komposit-Doublebase-Treibstoffen (CMDB) beschrieben. Die Berechnung der Energie wurde durchgefiihrt mittels eines thermodynamischen Rechenprogramms. Die Abbrandgeschwindigkeiten der Treibstoffe wurden nach der Strand-Burner-Methode bestimmt. Bei den AP-haltigen Treibstoffen nimmt die Energie zu und der Druckexponent ab mit zunehmendem AP-Gehalt. Wenn Ammoniumperchlorat teilweise oder ganz ersetzt wird durch die Nitramine HMX oder RDX, dann wird der spezifische Impuls verbessert und der Druckexponent nimmt unweigerlich zu. Eine Mischung von Bleisalicylat oder Blei-ortho-aminobenzoat und Kupfer-2,4-oder 3,5-dihydroxybenzoat erzielt eine beachtliche Wirkung auf das Abbrandverhalten des CMDB-Treibstoffs. Es wurde beobachtet, dal3 der Druckexponent abnimmt von 0,66 auf 0,48 bei Zusatz von Blei-und Kupfersalzen mit 3,0% fur Komponente Al-A1, von 0,82 auf 0,60 bei Zusatz von 2,0% fur Komponente RDX-A1 und von 0,72 auf 0,54 bei Zusatz von 2,5% fur Komponente RDX-AP-Al.Contenu energetique e t exposant de pression de combustibles double-base composites modifies Dans la prtsente ttude, on dtcrit une analyse du contenu tnergttique et de variation de l'exposant de pression pour des combustibles double-base composites modifits (CMDB). Le calcul de l'tnergie a Ctk effectu6 au moyen d'un programme de calcul thermodynamique. Les vitesses de combustion des combustibles ont t t t dttemintes par la mtthode de Strand-Burner. Pour 1es combustibles a base de perchlorate d'ammonium (AP), l'tnergie augmente et l'exposant de pression diminue lorsque la teneur en AP augmente. Lorsque le perchlorate d'ammonium est partiellement ou complktement remplact par les nitramines HMX ou RDX, l'impulsion spkcifique Isp est alors amtli-orCe et l'exposant de pression augmente inevitablement. Un melange de salicylate de plomb ou d'ortho-aminobenzoate de plomb et de 2,4ou 3,5-dihydroxybenzoate de cuivre produit un effet remarquable sur le comportement de combustion du CMDB. On a observt que l'exposant de pression diminuait de 0,66 B 0,48 lors de l'addition de sels de plomb ou de cuivre B 3,0% pour les composants AP-A1, de 0,82 B 0,60 lors d'une addition 2. 2,0% pour les composants RDX-A1 et de 0,72 B 0,54 lors d'une addition B 2,5% pour les composants RDX-AP-Al. SummaryThe paper describes an analysis on the energy and pressure exponents of composite modified double-base (CMDB) propellants. The evaluation of the energy was conducted by means of a thermodynamical program. Propellant burning rates were determined by the strand burner method. In the AP-based composition, the energy is enhanced and the pressure exponent reduced with increasing AP content. When AP is partially or entirely replaced by the nitramines HMX or RDX, Isp is improved, and the pressure exponent is inevitably increased. A mixture of lead salicylate or lead o-amino benzoate and copper 2,4-or 3,S...