The flow in centrifugal pumps is exceedingly complex, involving curvature, system rotation, separation, turbulence, and secondary flows. Moreover, the geometry is often asymmetric due to the volute shape. As a result, the relative motion between impeller and volute generates an unstableness which affects not only the overall pump performance, but is also responsible for pressure fluctuations, h...

The analysis of impeller shape performance was carried out with the SST (Shear-Stress Transport) model coupled with the streamline curvature turbulence model. This model combines the advantages from the κ−ε and κ−ω models, ensuring proper relation between turbulent stress and turbulent kinetic energy and allowing accurate and robust prediction of the impeller blade flow separation. The Multiple...

This work describes the potential consequences associated with operating a centrifugal compressor in overload. Nomenclature is offered to explain what is meant by overload operation, and methods that are used by original equipment manufacturers (OEMs) and end users to define overload limits are presented. The paper also describes the conditions that can lead to overload operation. Computational...

Turbulent kinetic energy and turbulent dissipation are important aspects of the flow field characteristics, which can affect wear loss in mixing equipment. In order to increase equipment process, a series fractal impellers were designed based on iteration method, effects dimension number iterations characteristics investigated. Firstly, distribution its uniformity studied. Then, rate studied in...

The absence of a systematic scale-up approach for biological conversion of cellulosic biomass to commodity products is a significant bottleneck to realizing the potential benefits offered by such conversion. Motivated by this, we undertook to develop a scale-up approach for conversion of waste paper sludge to ethanol. Physical properties of the system were measured and correlations were develop...

In this paper, we propose a dynamical model for pulsatile flow estimation of an iRBP. Noninvasive measurements of the motor power (V I) and pump impeller rotational speed (ω) were acquired from the pump controller and used together with blood hematocrit (HCT ) values as inputs to the model. A circulatory mock loop was operated with different aqueous glycerol solutions, mimicking different value...

In high-power impeller industries, valve-controlled liquid-filled hydrodynamic couplings are widely used in the soft startup of heavy-duty scraper conveyors for mining. However, water circulation speed internal flow fields is higher at lower ratios, making prone to severe cavitation, which further results performance degradation, noise, vibration, or even erosion failure. Meanwhile, because a c...

The effect of ultrasound on the pseudo-solubility of nitrogen in water and on gas-liquid mass transfer kinetics has been investigated in an autoclave reactor equipped with a gas induced impeller. In order to use organic liquids and to investigate the effect of pressure, gas-liquid mass transfer coefficient was calculated from the evolution of autoclave pressure during gas absorption to avoid an...

Vortices forming near the slag-steel interface in the mold can entrap inclusions and cause defects in continuous casting of steel slabs. Lab experiments employing a 1/3 rd scale water model were performed to quantify the effects of stopper rod asymmetry on vortex formation. Three stopperrod placements (aligned, front-misaligned and left-misaligned) were considered. Vortex formation was visualiz...