VALIDATION OF EQUATIONS LECKNER FOR CALCULATE THE EMISSIVITY OF GAS COMBUSTION MIXTURE OBTAINED FROM THE COMPARATION WITH THE METHOD OF HOTTEL AND THE APPLICATION ON AN INDUSTRIAL THREE BED REGENERATIVE CHAMBER COMBUSTION UNIT

This paper investigates the validity of the LECKNER to calculate the of mixture of gas combustion in by H. and R. J. Tucker method for enclosures with surfaces exposed to significant thermal radiation. The analysis is focused on a specific combustion chamber in a three-bed regenerative oxidizer and calculates the coefficient of absorption and the corresponding thermal irradiation flux exchanges among the hot wall surfaces of the chamber. The temperature distribution and the initial composition of the gaseous mixture at the inlet plane were assumed known.

RESEARCH ON CHARACTERISTICS OF TURBO JET ENGINE COMBUSTION CHAMBER

The characteristics of the combustion chamber of turbo jet engine with various parameters are examined in this article. The scientific works of other authors analyzing operating parameters of the jet engines were reviewed. Their recommendations were considered. Computer simulations of the combustion chamber were performed using different combustion reactions. The exhaust gas temperature and its dependence on the combustion mixture were determined. A practical study was also carried out, during which the experimental exhaust gas temperature was measured, and the trends of temperature change were determined. After analyzing both theoretical and practical results, the conclusions are presented.

Study influence factors of the spraying process on the properties of electric arc spraying coatings

The paper considers possibilities to increase the wear resistance, corrosion resistance, and service life for parts machines and mechanisms via their hardening and renovating using electric arc coatings characterized by high density, adhesion strength, and micro hardness thanks to activation of the spraying process. Also, the possibility of controlling the properties of restored surfaces owing to choice of the related equipment with required structure and characteristics in order to prolong the service life of machinery parts is shown. The right choice of equipment for spraying makes it possible to increase the speed and temperature of the spraying gas and particles, reduce the droplet diameter, increase the density and reduce the oxidation of coatings. The influence of spray factors such as the flow rate and pressure of working gases, composition of combustion mixture, spraying distance, dispersion of the spray, properties of wire material, etc. on the properties of the coatings obtained has been investigated. The possibility of controlling the properties of surfaces owing to choice with required characteristics electric arc coatings is shown. The influence of spray factors such as the flow rate and pressure of working gases, composition of combustion mixture, spraying distance, dispersion of the spray, properties of wire material, etc. on the properties of the coatings obtained has been investigated. The use of coatings makes it possible to increase the wear and corrosion resistance of working surfaces of machine parts and mechanisms, in particular ship parts, and so to reduce the costs of alloyed steels and alloys. The coatings application is associated with implementation of a fundamentally new approach, according to which the strength and carrying capacity of a part is provided by its basic material, whereas the resistance to corrosion, wear, and other factors may be increased via using hardening protective coatings. There are many alternative methods for producing coatings, from which it is advisable to choose an optimal, easy to implement, and inexpensive one. Of the variety of methods for hardening coating deposition, the most common technologies used to restore and improve the performance properties of parts are gas-thermal spraying techniques, among which the cheapest and simplest method is electric arc spraying (EAS), whose current improvement is aimed at modifying and activating the spraying process. Such combined technologies do not require additional expensive equipment and operations, which predetermines a reduction in the cost of hardening processes.

Low-cost VO2(M1) thin films synthesized by ultrasonic nebulized spray pyrolysis of an aqueous combustion mixture for IR photodetection

We report detailed structural, electrical transport and IR photoresponse properties of large area VO2(M1) thin films deposited by a simple cost-effective two-step technique.

Vehicle SI Engine with MPI of Liquid State LPG

The first part of the article reviews the possible methods for LPG and air mixture forming (injection of gaseous or liquid state LPG) and their influence on the operating properties of an SI engine. The next chapter explains the processes that take place when liquid state LPG is injected into the air flow of an internal combustion engine intake manifold. A simplified calculation is used to show that the injection of liquid state LPG is associated with extreme low temperature of the LPG injected into intake manifold and with ice formation on the outlet nozzle. The article sets out the design of an end part injector (EPI) for liquid state LPG that reduces the risk of icing of the outlet nozzle. The results of experimental research indicate very good operational properties for a vehicle SI engine with the combustion mixture formed by the injection of liquid state LPG into the engine intake manifold. The calculation results are confirmed by recording plots of LPG pressure inside the end part of injector (EPI) and the temperature on the outlet nozzle (ON) of the LPG injector. Visual inspection of injection of liquid state LPG into the intake manifold clearly supports the performed measurements. The conclusions summarize the knowledge gained from the laboratory investigation of liquid state LPG injection into an engine intake manifold.