In this work a three-dimensional finite element study is carried out of pressurized piping tee (tee) intersections, with local area wall thinning (LTA). Two types of stress analysis are carried out, dealing respectively with the determination of the stress concentration factor (SCF), and of the plastic collapse load. Stress values determined for vessels with uniform thickness are compared with previously published work. An evaluation is then made of the effect on the SCF values of varying the size and shape of the LTA around the intersection. This is followed by a parametric study in which the SCF and the collapse load are computed for intersections with different depths of wall thinning. Finally, comments are made on the fatigue of tees with LTA having cyclical loading superimposed on the constant pressure loading.

Compression period in a diesel engine is generally seen as initial characteristics before injection into combustion chamber. A free-piston type rapid compression machine (RCM) has been designed simulate the combustion phenomena in order to observe the chemical and physical kinetics studies at elevated pressures and temperatures. Purpose of this study is to clarify the effects of wall cylinder temperature on air heat release, especially during compression period. This method can a light piston is pneumatically shot and gets hammered in stopper at compression end. Measurements were made on a light piston compress in a rapid compression machine (RCM) with intended to simulate the actual compression period related phenomena. During this phenomena, the ambient temperature influences from the cylinder wall temperature has appear beneficial for the biodiesel fuel premixing and achieving best mixture preparation There are three tests will used to investigate the effects of the variant temperature of wall cylinder during compression period. Results show high temperature on cylinder wall will be effects decrease during temperature drop after compression stroke. The new characteristics rapid compression machine (RCM) is to develop and analyse before combustion process. IntroductionIn recent year, the new alternative fuel must be created for accommodate the user requirements. Biodiesel is one development of alternative fuel on the future. The increase in oil prices in the world market, coupled with a reduced supply of fossil fuels are not renewable[1], has caused concern for the need for renewable energy sources to replace fossil fuels. Many methods will use for research to develop the properties and performances about the biodiesel. In modern technology, the rapid compression machine is an instrument designed to simulate a single small engine of an internal combustion engine [2][3][4][5]. For purpose of elementary study on diesel combustion, it is therefore advantageous to employ a single shot burning device compare to the ordinary engine. An alternative method is to be use which attains high pressure and temperature by compressing air using moving piston [6][7]. In the present study, the new design rapid compression machine is to develop to enable to investigation on basic aspects of the diesel combustion including compression period, ignition and mixture formation [8]. Basically, this machine can operate by bombing gas nitrogen consists of a long cylinder and a light free moving piston [9][10]. Piston is bombing to compress air in the cylinder and finally attaining in constant volume chamber.The different temperature of wall cylinder was investigated on air heat release to look pattern graph of pressure against time [11][12].

In this work, a probabilistic fracture mechanics analysis of multiple cracks in a cylindrical pressure vessel was conducted. The analysis was performed to predict service life of a pressure vessel with a certain level of reliability if the vessel has a multiple internal surface cracks that interact each other. The stress intensity factor of multiple cracks configuration was determined from the stress intensity factor of a single surface crack in a plate subjected to uni-axial load and the interaction factor between the cracks. In this work, the Swift’s crack link-up criterion was employed. These parameters together with several other stochastic parameters, i.e. initial crack size, Paris’s crack propagation constants and fracture toughness, were then used to calculate the probability of failure with a certain level of reliability. The failure probability was simulated using guided direct simulation, for cycle-by-cycle crack propagation, to find the expected service life and the mode of failure (leak or break). A case study of a high-pressure vessel having different initial crack sizes have been simulated and the service life with 99,99% reliability were determined.