In this research, a computer code is developed to predict the interior ballistic parameters (variation of pressure and temperature of propellant gases, location and velocity of projectile versus time) based on Baer & Frankle zero dimensional method. Nonlinear BURNING RATE equation has been used. Volume term in the equation of state has been modified considering co-volume of propellant and igniter gases and the overlap between projectile, cartridge and recoil. Results obtained from this method are improved by correcting heat loss relations and considering energy losses due to recoiling parts of the gun and projectile spin. The calculated results are in good agreement with experimental data as well as the data reported from other interior ballistic codes. Investigation was performed to reveal the effect of co-volume of propellant gases, engraving force and shot-start pressure on the breech pressure. Also effect of igniter properties on the temperature and pressure history of burnt gases has been studied.

The BURNING RATE of single base propellant can be increased if they are used or stored in warm climates area. The use of INHIBITORs in this type of propellants reduces the BURNING RATE and finally the pressure and muzzle RATE at high temperatures and improve the ballistic performance of propellant. Several INHIBITORs, e.g. camphor, dibutyl phthalate, cellulose or unsatuRATEd organic esters compounds, have been used but preferred INHIBITORs are thermoplastics cellulose containing repeated units of the anhydroglucose. In this study, 1.5, 3, 7, 10, 12% wt of cellulose acetate butyRATE (CAB) were deposited on the surface of single base propellant and then the ballistic performance (pressure and muzzle RATE) have been evaluated.

In this study, the combustion characteristics and BURNING RATE of RDX/AP/Al/HTPB composite solid propellant were studied experimentally. Five different RDX-based propellant compositions have been formulated and the BURNING RATE and calorimetric value were evaluated. The BURNING RATEs of RDX composite solid propellants increased with increasing RDX content. The data obtained from experimental tests indicates that increasing weight percentage of RDX in the formulation increases the pressure exponent and decreases the BURNING RATE constant. The mentioned parameters related to the propellant without RDX compared with other formulations including RDX. The results show that the BURNING RATE of the propellant without RDX at the constant pressure of 800Psi was 7.2 mm/s and as RDX content increased by 13.6%, the BURNING RATE decreased to 5.5 mm/s. The relationship between the BURNING RATE and RDX content was not linear. It was also found that the pressure exponent increased by increasing RDX content. As a result, the pressure exponent belonged to the based propellant was 0.22 that by increasing the percent of RDX to 13.6%, the pressure exponent increases up to 0.3.

This research is conducted to study acceleration effect on the BURNING RATE augmentation of an aluminized solid propellant based on HTPB as an effective factor determining combustion chamber pressure. A centrifugal experimental setup was designed to obtain a uniform acceleration field by rotating the test motor around its longitudinal axis. A cylindrical port propellant grain was used in the test motor which had an inner diameter of 30 mm, an outer diameter of 60 mm and a length of 52 mm, so acceleration vector was always perpendicular to inner BURNING surface of propellant. Inner radius of tube was small, so the magnitude of acceleration increased as the grain burned back. The pressure of combustion chamber was changed from 30 bar 80 bar by changing the nozzle throat and the magnitude of acceleration changed from 2g to 60g by changing the rotational speed of solid rocket motor. Pressure of combustion chamber was measured. An analytical 0D code was used to compute BURNING RATE augmentation of propellant in acceleration field. Nozzle throat diameter is another parameter controlling the pressure field of combustion chamber of solid rocket motor. Thermomechanical erosion of nozzle throat is significant in aluminized propellant, so erosion of graphite throat insert was measured and taken into account in 0D code. BURNING time of all tests was below 2 sec. due to small web of the grain. As investigated, at low acceleration level (below 5g), BURNING RATE of propellant is not sensitive to acceleration while in the condition in which acceleration changed from 30g to 60g, BURNING RATE augmentation ratio increased from 1 to 1. 5. The transient behavior of BURNING RATE augmentation in acceleration field was obvious in obtained results due to short burn time of SRM. At high acceleration level, inner cylindrical surface of INHIBITOR was coated with aluminum oxide particles.

The BURNING RATE plays animportant role in determining the performanceandballistic behavior of solid rocket propellant. In this paper, the effect of various factorson BURNING RATE, such as combustion chamber pressure, poropellant grain initial temperature, fuel/oxidizer ratio, composition of the components propellant, oxidizer particle size, motor rocket size, and grain size have been investigated. For this purpose, technologies, methods, and various laboratory equipment are used, the most important of which are the methods such as Crawford, Closed Vessel, Ultrasound Measurement, Microwave, X-Ray X-ray, Plasma Electrical Capacity Measurement, Optical Techniques, Audio Publishing Systems. All of these methods are used in leading countries to measurethe propellants BURNING RATE. Consequently, the appropriate method andequipmentconsidering general aspects (operational, economic, functional, safety, etc. ) can be selected, comparing the advantages and disadvantages of each above-mentioned technologies, equipment and methods forthedetermination ofthe BURNING RATE of solid propellants.

This paper is dealing with the development of a new version of an existing BURNING model for predicting the BURNING RATE of different pyrotechnic mixtures of magnesium and sodium nitRATE. Modifying some parts of the model including BURNING time of magnesium particles, thermo physical properties of combustion products, and the mixture density, the BURNING RATE has been predicted for different values of mixture composition and combustion pressure. Comparison of the predicted and available experimental values of the BURNING RATEs shows good agreements, especially in pressure dependency.