Numerical Prediction Ofair Entrainment in Pump Intakes
نویسنده
چکیده
Pump intake is designed to provide adequate water supply to pumps. It is essential to design the pump intake to provide fairly uniform and swirl free flow to pumps. However, it is not always possible due to site constraints. Investigation of pump intake is required prior to installing the pumps at site. There are two approaches (experimental and numerical) followed for such investigation. The present paper describes a case study wherein air entrainment (vortex with full air-core) was observed in experimental study at lowest water level (LWL) in the original geometry. The pump intake was modified with a goal to eliminate air entrainment. The experimental model was built with these modifications and the air entrainment was seen to be eliminated. The model was investigated using a numerical approach. A commercial code was used to carry out two-phase flow studies to capture air entrainment. The paper brings out results and observations from both numerical and experimental approaches.
منابع مشابه
Effect of impeller speed on properties of quiescent zone and entrainment in mechanical flotation cells
Flotation process in mechanical cells is carried out in highly turbulent conditions. In this work, the impact of impeller speed on four characteristics of the quiescent zone, i.e. zone height, turbulence, solid percentage, and gas holdup, and their relationship with the entrainment is investigated, and it is shown why at a higher impeller speed, entrainment is not significant. The height of the...
متن کاملOverview of Direct Numerical Simulation of Particle Entrainment in Turbulent Flows
An overview of removal and re-entrainment of particles in turbulent flows is presented. The procedure for the direct numerical simulation (DNS) of the Navier-Stokes equation via a pseudospectral method for simulating the instantaneous fluid velocity field is described. Particle removal mechanisms in turbulent flows in a duct are examined and effects of the near-wall coherent eddies on the parti...
متن کاملPerformance of a Two-stages Gas Gun: Experimental, Analytical and Numerical Analysis
Two stages gas guns are used for various purposes, particularly for mechanical characterization of materials at high rate of deformations. The performance of a two stages gas gun is studied in this work using the theory of the two-stage gas gun proposed by Rajesh, numerical simulation using combined Eulerian/ Lagrangian elements in Autodyna commercial code and experiment using a two stage gas g...
متن کاملA Closer Look at Boundary Layer Inversion in Large-Eddy Simulations and Bulk Models: Buoyancy-Driven Case
The inversion layer (IL) of a clear-sky, buoyancy-driven convective boundary layer is investigated using large-eddy simulations covering a wide range of convective Richardson numbers. A new model of the IL is suggested and tested. The model performs better than previous first-order models of the entrainment and provides physical insights into the main controls of the mixed-layer and IL growths....
متن کاملNumerical Study of the tongue geometry effects on the cavitation and performance of a centrifugal pump in off-design conditions
In this study, the effects of the volute tongue geometry variation on the head, efficiency, velocity distribution and cavitation structure of a centrifugal pump in the steady flow behavior under off-design conditions have been investigated. Numerical simulation modeling based on the turbulence model with a hybrid grid is used to simulate the flow within the modeled pump. The flow is simulated ...
متن کامل