Search results

The purpose of the paper is numerical simulation and experimental analysis of a cavitation operating regime in a centrifugal water pump. The main goal is to extend the mathematical model to be able to predict the phenomena where thermodynamic process is controlled by an hydrodynamic flow pattern.

The mathematical model is being extended and used for numerical simulation of an unstable operating regime in a water pump. Numerical simulation results were compared to thermal imaging system visualisation and flow variables measurements results.

The presented approach increases the system stability. The model can be used for simulation of system instabilities that involve not just the pump characteristics but those of the complete piping system. Modified turbulence model including compressibility effects lead to reliable simulation results of pump unsteady cavitation behaviour.

The research was limited to an homogenous cavitation transport model based on the additional transport equation approach. The validation results are connected to a single commercial radial water pump geometry and the numerical domain size is limited by computer capability.

The work extends the application of an homogenous cavitation model to the complicated flow regime using advanced turbulence modelling. The re‐entrant jet behaviour in a rotating pump is modelled successfully. The work adds the value of numerical simulation models to engineering problems in fluid machinery.

Aging of the oil wells leads to a decrease in reservoir pressure and also to an increase in the water, gas and abrasive particles content. Therefore, there is a need for the oil pumps exploitation characteristics improvements. This paper aims to generate a valuable numerical model which will provide a useful tool to study various cases.

Computational fluid dynamics (CFD) analysis of the generation of so-called coherent structures of eddies and turbulence in the peripheral area of the vortex rotor mounted at the back side of centrifugal rotor was undertaken. After detailed analysis of the influence of the used turbulence models on the results, a hybrid turbulent model Detached Eddies Simulation (DES) was chosen as the most suitable.

Numerical control volume method with unsteady solver and DES turbulence model was proven to be valuable tool for flow analysis in the centrifugal pumps. Having in mind that DES turbulence model consumes much less computational time than large eddies turbulence model, this is a very useful fact that resulted from this research.

The proven numerical model is robust and reliable enough to become a standard method in simulating flow and other physical phenomena occurring in centrifugal pumps and similar turbo machines. This makes it possible to easily research different factors that influence their performances.

Comprehensive experimental and CFD study was performed which made it possible to conduct detailed validation and verification of described CFD model.

This study aims to present the analysis of methods for cavitaion surge obstruction in water pump systems with particular focus on the two different inlet geometry configurations.

A cavitating flow field was simulated by RANS based computational fluid dynamics (CFD) program for different pump configurations operating in the unstable cavitation regime, inducing surging process. Numerical simulation results were compared to visualization and measurements results.

Presented results show that a hydro dynamically induced surging regime could be limited and further advantages regarding operating characteristics of radial pumps could be achieved with presented geometry modifications.

This study provides insight into complicated transient cavitation flow patterns in conventional centrifugal pumps and introduces effective geometry optimization ideas useful to researchers and engineers in the area of fluid dynamics and hydromachinery.