ROCOM is a four-loop test facility for the investigation of coolant mixing in the primary circuit of pressurized water reactors. Recently, a new sensor was developed for an improved visualisation and quantification of the coolant mixing in the downcomer. This new sensor spans a dense measuring grid and covers nearly the whole downcomer. In the presented work, special emphasis was given to the c...

The unsteady aerodynamic behavior of a bird-damaged fan stage at the inlet of a highbypass turbofan engine is examined with a computational fluid dynamics (CFD) aerodynamic model suitable for use in an aeroelastic response calculation. ANSYS CFX, a commercially available CFD solver, is utilized to perform the steady-state and unsteady CFD calculations for the undamaged and damaged fan. The dama...

High-pressure air enters the air-turbine of the dental handpiece and strikes the blades to drive the impeller. The air-turbine has impeller and the air tube is connected to the air-turbine housing. The flowfield of the air-turbine were investigated for the optimum air-turbine design using ANSYS CFX. The objective of the research was to find an optimum design variables for the air-turbine to inc...

Flow fields and bubble size distribution are two critical issues in the determination of mass transfer and reaction rate in bubble columns. In this work the hydrodynamics of bubble driven flow was investigated in a laboratory scale cylindrical bubble column. The column was a semi batch reactor which was initially filled with tap water and only gas was evenly fed to the column from the bottom wi...

An external liquid circulation is introduced into a traditional internal loop reactor in order to improve liquid circulation and increase the interface between gas and liquid phases. The effects of superficial gas velocity and external liquid circulation velocity on local and overall gas holdups are explored experimentally and numerically in the loop section of a combined gas-liquid contactor, ...

In this paper a detailed model of a VVER1000 reactor pressure vessel (RPV) with the extension of simplified primary loops is presented (Loop model). The primary loop components like steam generators and pumps are modelled by the outer shapes and additional source terms for energy and momentum exchange. The RPV model part is tested without primary loops and compared with former results obtained ...

This paper investigates the influence of the propeller on the drag of twin self-propelled AUVs, firstly, to examine the fleet performance for various propulsive conditions of leading and following AUV and, secondly, to study the parametric influence of transverse separations and longitudinal offsets on the fleet’s drag. A series of CFD RANS-SST simulations have been performed at the Reynolds Nu...

Many flow regimes in Nuclear Reactor Safety (NRS) Research are characterized by multiphase flows, where one of the phases is continuous and the other phase consists of gas or vapor of the liquid phase. The validation of the CFD multiphase flow models against detailed experimental data for simplified flow configurations is a basic requirement for the accurate prediction of more complex flows, li...

In the present work are presented results from numerical simulations performed with the ANSYS-CFX code. It is studied a radial diffuser flow case, which is the main academic problem used to study the flow behavior on flat plate valves. The radial flow inside the diffuser has important behaviors such as the turbulence decay downstream and recirculation regions inside the valve flow channel due t...

Turbulence analysis of flow inside a hydrocyclone is carried out using commercially available CFD software ANSYS-CFX (release 11.0). Commercial CFD software(s) and their turbulence models have come a long way in accurately predicting the flow inside a hydrocyclone, both at the mean as well as at the turbulence level. Previous studies have shown, the more accurate the turbulence prediction is, t...