The aerodynamic performance of an airfoil of the shape NACA
4415 was investigated using CFD numerical analysis.
The study of the phenomenon of ship squat in vessels can be considered as one of the
most important topics in ships hydrodynamic science, because it is related to the marine
secure, especially now after the rapid increase in size of vessels and ope
ration speeds. In
literatures there are methods that are used to predict ship squat.
This research aims to develop a 3D Numerical Modeling to analyze the phenomenon
of ship squat of the ship in Canals using computational numerical method and proper
software, to extract the velocity and pressure fields of the flow around ship hull. The last
one affect directly this phenomenon.
To build a 3D model and to represent ship squat for viscous flow, simulation has
been developed using Gambit and Ansys Fluent programs.
ship squat has been integrating the motion of water level drop. The effect of vessel
speed and blockage factor Cb have been taken into account.
Results confirm the efficiency of the CFD for simulating ship squat. The comparison
with other experimental and computational methods show good accuracy.
It is a cross in the hydraulic systems with long pipes case modeling of the hardest and most important cases in search. Of the most important and is considered Query to achieve study the changing resistance model is used to describe the changing liqu
id flow in the tube. As described by knowing the nature of the shear stress to the pipe wall and also know the nature of the flow ( laminar or turbulent ). The results of simulations of hydraulice shock caused by the sadden move of the hydraulic control valve which studied in the following cases:
1- Hard to improve the discharge of the pump rate.
2- Improve the discharge of the pump variable rate finally; compare the results of computer simulations with experimental results.
We present in this paper a graphical study of regions of thermally deposited
ZnS thin films on glass by atomic force microscope (AFM). This study consists
of volume parameters and functional parameters of these films surfaces for the
object of inv
estigating the possibility to retain fluids by these films. For doing
so, we registered Abbott-Firestone curves that are based on height distribution
for these films, we measured volume and functional parameters in the whole
pores. Using the thresholding operator we followed parameters distribution in
depth of the surface. At the end we compared these parameters by the results of
another study based on slice selection at different levels.
إن بعض أجهزة قياس الغزارة التي تعتمد في عملها على قياس تواتر الدوامات التي تتشكل خلف حاجز
مغمور في السائل تكون كثيرة الدقة عندما يتم قياس تواترها عن طريق قياس عدد الدوامات التي تؤثر
في صفيحة مستوية متوضعة ضمن السياج المتشكل خلف الحاجز.
و بذلك نستط
يع اعتماد عدد ستروهال جديد ثابت مستقل ليس له علاقة بنسبة التضـايق
و لقـد درست الخصائص المميزة لهذا الجهاز في الحالتين: الجريان المستمر و الجريان غير المسـتمر و هـذا
الجهاز يستخدم كجهاز قياس عددي.
