The jet fuels anti-wear properties indicator

There are three main fuel brands for jet engines of civil aviation used: domestic TS-1 and RT and foreign, produced in relatively small volumes in Russia, JET A-1 (JET A-1). Since the end of the 2000s, foreign manufacturers have made claims to the quality of the mass-used domestic fuel brand TS-1, and these claims have not been specified. However, the service life of a number of foreign engines operating on TS-1 fuel has been reduced by 50%. This circumstance can be caused by both subjective reasons – commercial and political interests of equipment manufacturers, and the objective ones. The main objective reason may be that recently several Russian plants producing TS-1 fuel have begun to produce composite propellant under the same name, where products of secondary oil refining processes are added to the straight-run fractions. These fuels meet the requirements of the standard (GOST 10227-86), which does not contain an indicator that characterizes the anti-wear properties of jet fuels. In the standard for JET A-1 fuel, anti-wear properties are normalized, and they are also normalized in the standard for domestic fuels for supersonic aviation. The article presents comparative tests of anti-wear properties of samples of jet fuels used in the civil aviation. The article substantiates the relevance of the anti-wear properties indicator in the standard for domestic brands of jet fuels for subsonic aircraft introduction, as well as the comparative analysis of the anti-wear properties of fuels produced by various Russian oil refineries. Indicators and methods for assessing the anti-wear properties of aviation fuels can be different. As such an indicator, it is proposed to use the anti-wear properties indicator calculated after testing fuel samples on a four-ball friction machine.

The Relation between Burning Time and Burning Energy of HTPB - Based Composite Propellant

This paper represented a result of several visions of chemical phenomenon and several extractions and extrapolations of experimental works which included a relationship between energy related to a chemical process and the relevant time which is required to achieve this process, but it must be taken into account that those mentioned experimental works hadn’t aimed substantially to study and state this relationship neither implicitly nor explicitly, but the results of those works have been exploited for another field after being compared with the relevant thermodynamic calculations. The selected case study for this paper was the relation between the burning time of Hydroxyl terminated poly butadiene propellant ( HTPB) and the caloric value of this material. The results reflected some relationship between the burning time and the change of the system energy during the burning process.

Improvement of Composite Propellants Energy Using Explosive Materials

Composite propellants are energetic materials have ability to ignite, burn fast and cause several simultaneous exothermic chemical reactions which produce huge amounts of gases under high pressures and temperatures which can spread spontaneously. 1n the present study, the explosive material hexogen (Cyclo tri-methylene tri-nitramine) was used to improve the performance properties of composite propellants, especially the specific impulse. For several formulations of hexogen at different added percentages, the specific impulse was calculated using thermodynamic calculations program of composite propellants. The results given were compared with those formulations not including hexogen. It was seen that; hexogen caused a significant positive effect in the specific impulse. Accordingly, the energy of composite propellant was improved positively in the samples containing hexogen till 40% of the oxidizer ratio. Also, it was noticed that the specific impulse began to decrease gradually for the oxidizers containing more than 40% of hexogen which caused in a decreasing of composite propellant energy. Finally, it was concluded that, the use of some amount of explosive materials like hexogen can improve composite propellants energy successfully.