In this study, the operating processes of a four-stroke diesel marine engine from intake valve closing (IVC) to exhaust opening (EVO) at numerous different charge air conditions were simulated with AVL FIRE code. The CFD models validated shop-test technical data. results showed that increasing pressure without cooling decreased actual amount supplied cylinder. As result, combustion process was ...

the usage of turbochargers in diesel engines has led to the downsizing of the motors as well as usage of the waste gates in turbochargers. any dimensional reduction in turbochargers and appurtenant leads to an enhancement on the performance of internal combustion engines and in environmental problems in terms of aerodynamic, thermodynamic and mechanical specifications for both engines and turbo...

To study the three-dimensional size, shape, and motion of the mitral leaflets and annulus, we surgically attached radiopaque markers to sites on the mitral annulus and leaflets in seven sheep. After 8 days of recovery, the animals were sedated, and three-dimensional marker positions were measured by computer analysis of biplane videofluorograms (60/s). We found that the oval mitral annulus beca...

A control-oriented two-zone charge mixing model is developed to simplify, but to describe mixing of fresh charge and residual gas during the intake stroke. Engine valve timing has a strong influence on the realization of stable homogeneous charge compression ignition (HCCI), since it affects turbulent flow that promotes mixing of fresh charge and residual gas. Controlled auto-ignition of a HCCI...

With great interest we read the article of Haj-Ali and Marom et al., presenting an extensive three-dimensional mathematical model of the aortic valve and root (Haj-Ali et al., 2012). The development of an accurate model of the aortic valve could provide insight in both the functioning of a healthy valve and several pathological processes involving the aortic valve. As the aortic valve interacts...

In conventional vapor compression systems, electronic expansion valves (EXVs) are used for refrigerant flow control. Subcooled refrigerant enters the expansion device and is expanded to the evaporation pressure while the valve opening is modified to achieve the desired mass flowrate. The relationship between the inlet and outlet conditions, the opening, and the mass flowrate has been extensivel...

Respiration in fishes involves buccal pumping, which is characterized by the generation of nearly continuous water flow over the gills because of the rhythmic expansion/compression of the pharyngeal cavity. This mechanism is achieved by the functions of the vascular, skeletal, and muscular systems. However, the process by which the embryo establishes the mechanism remains a mystery. Morphologic...

A model based control scheme is designed to regu late the cylinder air charge of a camless multicylinder engine for unthrottled operation The controller con sists of a feedforward and an adaptive feedback scheme based on a control oriented model of the breathing process of an engine equipped with electro hydraulic springless valve train The nonlinear control scheme is designed to achieve cylind...

Sixteen years after Laennec (1819) described the murmur of mitral stenosis, Bouillaud (1835) described a reduplication of the second sound in mitral stenosis. The familiar cadence in mitral stenosis, which results from the presence of this added sound, was likened by Durozier (1862) to the syllables ffou-ta-ta-rou. In 1872 Guttman suggested that this sound might be due not to asynchronism of pu...