Technology Reports of Kansai University (ISSN: 04532198) is a monthly peer-reviewed and open-access international Journal. It was first built in 1959 and officially in 1975 till now by kansai university, japan. The journal covers all sort of engineering topic, mathematics and physics. Technology Reports of Kansai University (TRKU) was closed access journal until 2017. After that TRKU became open access journal. TRKU is a scopus indexed journal and directly run by faculty of engineering, kansai university.
Technology Reports of Kansai University (ISSN: 04532198) is a peer-reviewed journal. The journal covers all sort of engineering topic as well as mathematics and physics. the journal's scopes are
in the following fields but not limited to:
The article deals with the internal ballistic of an air gun that utilizes the energy of compressed air to propel the projectile out of the barrel. In this study, a thermodynamic mathematical model describing the internal ballistic phenomena inside the working chambers of an airgun is developed. The core of this work is to derive a governing equation modeling the variation of gas temperature in a control volume including one or several incoming and outgoing mass airflow rates. A novel universal algorithm that allows to solve internal ballistics of all types of airguns is also developed and applied for the case of spring-piston airgun. To verify the mathematical model, the projectile muzzle velocity is measured using a Dopler radar system and compared to the theoretical result. The comparison reveals that the measured and calculated results of the projectile muzzle velocity are well agreed with the deviation less than 4%. Thus, the developed internal ballistic model of airguns and its solving algorithm can be used as a powerful tool to predict and improve the existing airguns performance or to design novel airgun systems.
In this work, modeling and determination of the stationary eccentricity and attitude angle for a short journal bearing with single external pressurization at an arbitrary point injection port are treated. As for hybrid journal bearing, both hydrodynamic and injection forces are simultaneously considered in the Reynolds Equation. Modeling of this point injection port is performed using a Dirac spatial delta function, which allows obtain pressure fields in closed analytical form. The pressure field given by analytical expression allows to determine, also in analytical form, the pressure force components, equilibrium eccentricity and attitude angle. A special case, when the applied load is collinear with the pressurized injection direction is analyzed, which corresponds to an injection port located at the upper part of the journal bearing. Tables relating eccentricity, attitude angle, external pressurization force and Sommerfeld number for the attained stationary position are given.
