During mold filling, molten metal can only advance as quickly as the AIR inside the cavity is expelled. In this work an analytical model describing AIR flow is developed based on a incompressible flow theory. AIR PRESSURE has serious effects upon the filling behaviour such as surface profile and filling time. In this work a new mathematical model is proposed for calculation the AIR PRESSURE during the mold filling. A single phase computational fluid dynamic code based on the SOLA-VOF algorithm used for prediction the fluid flow. AIR discharged through the vents is modelled by ideal gas assumption, conservation of mass equation and Bernoulli law. A new algorithm was developed to interpolates the AIR PRESSURE on the surface cell. The creation of AIR back PRESSURE was correlated with sizes of vents and pouring basin height. In order to verify the computational results a series of experimental test was conducted. Comparison between the experimental data and simulation results has shown a good agreement.

AIR pads are vastly applicable in ultra precision machines. Spindle and table are the two main components of these machines which get advantages of such systems. The performance and efficiency of AIR pads have big influence on the whole machine quality. Parameters affecting PRESSURE distribution of AIR tables may be considered as, 1) AIR compressing method, 2) AIR nozzle diameter, shape, and size, 3) number of AIR pads, and 4) AIR gap thickness. In this study, effects of AIR pad shape on PRESSURE distribution in AIR gap have been investigated using ANSYS. In this simulation, FOTRAN environment have been employed. Investigated shapes for AIR pads are triangle, rectangle, pentagon, hexagon, ellipse and circle. PRESSURE distribution-distance from orifice have been plotted for each AIR pad shape. The results indicate that the rectangle AIR pad has the best PRESSURE distribution.

‎AIR PRESSURE is an important measure for weather forecasting‎ , ‎and is also used in AIR transport‎ , ‎agriculture ‎, ‎NRM (Natural Resource Management)‎ , ‎astronomical observation‎, ‎geophysics‎, ‎geodesy ‎, ‎etc ‎. AIR PRESSURE is an important criterion for weather forecasting‎ , ‎and is also widely used in some branches of science ‎. ‎In this paper ‎, ‎we propose the " ARIMA model " for modeling AIR PRESSURE at the Isfahan AIRport meteorological station ‎.‎In the next step ‎, ‎the model assumptions will be examined ‎. ‎Finally ‎, ‎we will show how well the model describes the data . For convenience, all R code used in the paper is included at the end of the paper in the Appendix section.

Experimental and numerical investigation of multihole gasoline direct injection (GDI) sprays at high injection PRESSURE and temperature are performed. The primary objective of this study is to analyse the role of gas entrainment and spray plume interactions on the global spray parameters like spray tip penetration, spray angles and atomization. Three-hole 90° spray cone angle and six-hole 60° spray cone angle injectors are used for current work to examine the effect of the geometry of the injector on the spray interactions. The numerical results from Reynolds Average Navier Stokes (RANS) simulations show a reasonable comparison to experiments. The simulations provide further insight to the gas entrainment process highlights the fact that a stagnation plane is formed inside the spray cone which basically governs the semi collapse of spray that in turn affects the spray direction and cone angle.