Published data on flow field variation caused by various blade design patterns are scarce. Most designs exhibit significant flow separation and adverse pressure gradients effects that lower mixing efficiency. In view of the design potentials of the CFD methodology, the flow field variations caused by different blade designs could be classified in order to be able to predict the spread of the lo...

Based on the three-dimensional elliptic governing equations and the throttle model, an unsteady numerical simulation of rotating stall is undertaken in the case of G4-73 type centrifugal fan and the correctness of simulation results is verified by experiments. In this study a new rotating stall inception criterion is put forward, that the inlet flow or outlet back pressure fluctuations graduall...

The flow hydrodynamics in a low specific speed radial pump-turbine reduced scale model is experimentally investigated under off-design operating conditions in generating mode. Wall pressure measurements, in the stator, synchronized with high-speed flow visualizations in the vaneless space between the impeller and the guide vanes using air bubbles injection are performed. When starting from the ...

In this paper, extensive study of ring-opening polymerization ε-caprolactone (ε-CL) using lipase Novozym 435 as catalyst in flask level and reactor level were conducted. The polymerization rates increase with an increase in time up to 4 h after which there has been a steep decrease for all temperature from 50 to 100 °C in the flask level. The conclusion out of flask level and reactor level stud...

HeartWare is a third-generation continuous flow left ventricular assist device (LVAD) and generates centrifugal pattern of blood flow. In the perioperative setting, interrogating the HeartWare devices is very difficult due to the interference of the Doppler by the impeller frequency and generation of the waterfall artifact. We present a case where using color Doppler a view "inside" the impelle...

Abstract To improve the utilization rate of tidal current energy, Twin Half-rotating Impeller Tidal Turbine(THITT), a new type turbine was proposed based on half-rotating impeller(HRI) which lift-resistance compound impeller, and its virtual prototype established. By changing way impeller rotated, two kinds CFD models were established taken into Xflow to calculate. The differences in their velo...

the non-uniformity factor is used for correction of the formulas obtained from the one-dimentional fluid flow method in a centrifugal impeller pump. the variations of radial velocity at the outlet of five centrifugal impellers with the specific speed of about ns =50 are calculated at design point by using two-dimentional potentional flow method for an invisid fluid. on the other hand~ the varia...

The dissipation rate of turbulent kinetic energy () and shear rate (γ) are the key process parameters for mixing in surface aerators. At constant dynamic variables (rotational speed), both  and γ are greatly affected by the geometric parameters (impeller diameter, cross-sectional area of the tank, liquid height, rotor blade length and immersion height). By doing numerical computation by VISIM...

In this paper a rotational, radial-flux energy harvester incorporating a three-phase generation principle is presented for converting energy from water flow in domestic water pipelines. The energy harvester together with a power management circuit and energy storage is used to power a smart metering system installed underground making it independent from external power supplies or depleting bat...

This work aims to evaluate the efficiency of ultrasonic degassing when applied to the AlSi9Cu3 alloy when compared with other degassing techniques. The mechanism of aluminium degassing is discussed. A suitable ultrasonic degassing apparatus including a novel MMM (Multi-frequency Multimode Modulated) technology, able to supply up to 1.2 kW power under a frequency up to 25 kHz, was developed spec...