Beschleunigter Sinkprozess fester Partikel bei laminarer und turbulenter Umströmung

Separation of particles is often designed based on the terminal settling velocity as separation parameter. Until now, the particle state of motion is described by solving the force balance equation numerically, which is highly complex. In this work, algebraic equations are presented, which describe the temporal changes of the setting velocity and the displacement at sinking in laminar and turbulent flows around the particle. These equations solely depend upon particle size, density and shape and are independent of the initial velocity. Using the characteristic values, the time period where a sufficient convergence to the terminal sinking velocity is reached, can be clearly identified.     

Unterschiedliche Berechnungsmöglichkeiten von radialen Kreiselpumpen

Various Approaches to Calculations on Radial Centrifugal Pumps Computational fluid dynamics and present day computational hardware have attained a high level of sophistication. This paper reports numerical calculations on centrifugal pumps for steady state and transient conditions. Calculations carried out for one channel of the impeller and for the complete pump are presented. Flow between impeller and pump case was also considered. Very good agreement between simulations and experiments was obtained. The accuracy and the information content of the calculations rise with increasing complexity of the simulation.