Ballistic evaluationof LOVA propellant in high calibre gun

'This paper presents the data obrained on dynamic firing of a cellulose acetate binder-based low vulnerability ammunition (LOV A) propellant using 120 mm fin-stabilised armour piercing discarding sabot (FSAPDS) kinetic energyammunition. An optimised propellant composition formulated ~sing fine RDX as an energetic ingredient and a mixture of cellulose acetate and nitrocellulose as binder was qualified fit for firing in a high calibre gun by its successful static evaluation for absolute ballistics using high pressure closed vessel technique. Dynamic firing of the propellant processed in heptatubular geometry was undertaken to assess the propellant charge mass. This propellant achieved higher muzzle velocity as compared to the standard NQ/M119 triple-base propellant while meeting the non-vulnerability characteristics convincingly

Cellulose Acetate Binder-Based LOVA Gun Propellant for Tank Guns.

Cellulose acetate (CA) binder-based low vulnerability ammunition (LOYA) gun propellant formulations with varying percentages of fine RDX as energetic ingredient have been studied. RDX percentage varied from 76 to 80 in these formulations. An optimised composition with 78 per cent RDX was then studied exhaustively. Ballistic data determined by closed vessel (CV) evaluation and vulnerability aspects obtained by safety tests were then compared vis-a-vis the properties of standard triple base NQ composition. Theoretical prediction and CV test results indicated that the CA binder-based LOVA gun propellant Could satisfactorily meet the ballistic requirements for gun application

Role of Bimodal RDX in LOVA Gun Propellant Combustion

Present investigation reports the results of systematic studies on the use of bimodal RDX in low-vulnerability ammunition (LOVA) gun propellants. Several formulations based on bimodal RDX as oxidiser, cellulose acetate as binder, and diocty1 phthalate or triacetin as plasticizer were processed with different proportions of 5 micrometer and 20 micrometer particle size of RDX samples in the range 100:0 to 60:40 ratios. The effect of varying the proportion of fine RDX of the two particle sizes on propellant burning behaviour was found to be quite significant. The study concluded that by using bimodal RDX, it is possible to modify burning behaviour without sacrificing low-vulnerability aspects of LOVA propellants

Studies on Some Nitramine based Low Vulnerability Ammunition Propellants with Cellulose Acetate as a Binder

Several formulations of propellants based on RDX as an energetic solid ingredients and cellulose acetate (CA) as a binder were processed using either dioctyl pthalate(DOP) or tracetin(TA) as plastisizer and a small amount of nitrocellulose(NC). The Performance of these propellants was evaluated on the basis of closed vessel firing data. The vulnerability aspects of these formulations were compared with those of conventional picrite propellant, NQ on the basis of their ignition temperatures and sensitivity to friction and impact. Triacetin was found to be better plasticizer than DOP for CA binder. Some RDX/CA/TA/NC/-based propellants were found to have energy levels comparable with NQ propellant and had less sensitivity to heat, impact and friction, and therefore have the potential for being used as low-vulnerability ammunition propellants for gun applications

Studies on the Effects of RDX Particle Size on the Burning Rate of Gun Propellants

The ballistic properties of RDX-based propellants are highly dependent on the particle size of RDX used. The effect of RDX particle size on the burning rate and pressure exponent of the gun propellant was studied. Propellant formulation containing RDX to extent of 60 per cent in the composition was processed with varying particle size of RDX. Finished propellants in heptatubular and cord geometry were evaluated for ballistic aspects by closed vessel firing in a 700 cc vessel at a loading density of 0.18 g/cc. The data obtained clearly indicate that increase in particle size of RDX increases the burning rate as well as the pressure exponent

Process technology development for LOVA gun propellant

100-104"LOVA" gun propellants are formulated with the use of a suitable inert binder and a cyclic nitramine as the energetic ingredient. For the technology development of LOVA gun propellant a suitable manufacturing method was required to be developed. Manufacture of propellant formulation using cellulose acetate and RDX was tried by conventional solvent process by two different methods. In the first method the fine RDX was first desensitised by the plasticiser coating and the desensitised fine RDX was incorporated with the inert binder. In the second method a two stage process technology was adopted. In the first stage, the basic composition is prepared by wet mixing process and in the second stage the dry basic mix is solvent incorporated for extrusion into the required size and shape. The first method was termed as dry process and the second method as wet process. The comparative analysis of the ballistic aspects as determined by closed vessel firing indicated that the propellant batches made by the wet mix process gave consistent and reliable results, and has been adopted for the manufacture of 'LOVA' gun propellants

Thermal Stability and Shelf-life of High Energy Fuel for Torpedoes (Short Communication)

1,2-Dinitroxy propane-based liquid fuel is an advanced high energy fuel for torpedoes. The high energy fuel is used with an oxidiser, viz., hydroxyl ammonium perchlorate as a bi-propellant system for torpedo propulsion. Thermal stability of high energy fuel has been arrived at by differential thermal analysis and also by following the depletion in stabiliser content as well as increase in acidity with ageing. Rate constant for decomposition, activation energy for depletion of 2-nitro diphenylamine (2-NDPA) and shelf-life of high energy fuel have been determined. Due to the high vapour pressure of high energy fuel (because of 1,2-dinitroxy propane ), usual experimental set up could not be used and the sample was conditioned in sealed tubes. The shelf-life of high energy fuel is arrived at using Woolwich, Berthelot and Arrhenius equations and the results obtained are 100 years, 125 years and 276 years, respectively. Considering the safety aspect, the lowest value, viz., 100 years is recommended as safe life of high energy fuel. This work confirms the reported estimates of the good storage stability of high energy fuel