flow regime in dam's bottom outlet is divided in pressurized flow and free surface flow by the gate located for discharge control. down stream tunnel involves high velocity multi component air –water flow studied by mathematical model. in this research work, we used finite volume mixture two phase flow model. because of high reynolds number, standard two equations k-e turbulence model was ...

This paper focuses on simulations of enclosed air pocket movements in conjunction with bottom outlet operations. The critical velocity of water for air pocket transport in pipe is the minimal flow velocity for the air pocket start to move downstream. A numerical model is developed to simulate the critical velocity of air pocket transport in pipe flow and to discuss the impacts of tunnel slope, ...

Using experimental models along with conducting numerical analysis have been widely used in performance recognition and optimization of hydraulic equipments. Numerical modeling has lower cost rather than experimental one; however practical tests are commonly used because of the hydraulic structure importance especially in dams. Meanwhile numerical methods could be used for future designs throug...

Four cyclone concentrators were designed and fabricated to compare their particle separation and concentration behavior, such as the major, minor, outlet, and wall deposition fractions. Two of the cyclone concentrators were the conventional type, with the minor flow tube connected to the particle outlet at the bottom of the cyclone. The others were modified cyclone concentrators with a gap betw...

Using bottom outlets for drain and regulation of water level in reservior has significant importance in performance mahagment of dam. Amount of service and emergency gates opening have important role in pressure, velocity and discharge coefficient variations and finally dam performance. In the present research, flow aeration between emergency and service gates was studied with different hydraul...

In this study, cooling of a hot obstacle in a rectangular cavity filled with water-CuO nanolfuid has been examined numerically. This cavity has an inlet and outlet and the cold nanofuid comes from the left side of the cavity and after cooling the hot obstacle, it goes out from the opposite site. All of the walls are insulated, and the SIMPLER algorithm has been employed for solving the governin...

Aerators are applied to provide air entrainment and cavitation erosion protections for high-speed flows. By traditional chute aerators in high-head bottom tunnels, it is difficult maintain effective aeration protection low-Froude-number small-slope conditions. The present study explores a wedge aerator design at the outlet, detailed experimental data on cavity entrained diffusion were obtained ...

Conventional arterial-line filters commonly use a large volume circular shaped housing, a wetted micropore screen, and a purge port to trap, separate, and remove gas bubbles from extracorporeal blood flow. Focusing on the bubble trapping function, this work attempts to explore how the filter housing shape and its resulting blood flow path affect the clinical application of arterial-line filters...