Krystian Smołka

Experimental Research on Wet Steam Flow With Shock Wave

The article presents research on a wet steam transonic flow in a Laval half-nozzle with a shock wave. The motivation for this research was to investigate the shock wave/liquid phase interaction in the transonic wet steam flow. This phenomenon is responsible for the lack of good correspondence between experimental data and computational fluid dynamics results. For the tests, the geometry of the half-arc nozzle was used. The shock wave formation at the divergent section of the nozzle is caused by too high back-pressure. The observed instabilities in the flow are mainly initiated by the shock wave/liquid film (boundary layer) interaction. The numerical calculations were compared with experimental results with respect to the static pressure distribution along the nozzle.

Analysis of the steam condensing flow in a linear blade cascade

This study presents experimental and numerical testing of the steam condensing flow through a linear blade cascade made of blades of a 200 MW steam turbine last stage stator. The tests were carried out on an in-house laboratory stand and using an in-house numerical code modelling the water vapour flow with homo- and heterogeneous condensation. Additionally, this paper presents a comparison of calculations of a flow field modelled by means of a single-fluid model using both an in-house computational fluid dynamics code and the commercial Ansys CFX v16.2 software package. The aim of the research was to identify difficulties involved by comparing the numerical modelling results with the experimental data for a linear blade cascade. The experimental results, which are very well supplemented by those obtained from numerical computations, may be used to validate computational fluid dynamics codes.

Numerical analysis of the impact of pollutants on water vapour condensation in atmospheric air transonic flows

Abstract The paper presents a developed numerical tool in the form of a CFD code solving Reynolds-averaged Navier–Stokes equations for transonic flows of a compressible gas which is used to model the process of atmospheric air expansion in nozzles. The numerical model takes account of condensation of water vapour contained in atmospheric air. The paper presents results of numerical modelling of both homo- and heterogeneous condensation taking place as air expands in the nozzle and demonstrates the impact of the air relative humidity and pollutants on the condensation process.

Interphase processes analysis in moist air transonic flows in nozzles

During the flow of atmospheric air through convergent-divergent (CD) nozzles the water vapour contained in it can condense spontaneously. The resulting liquid phase may then undergo further phase transitions, e.g. evaporation on the shock waves arising in the nozzle divergent part. The subject of this paper is a numerical and experimental analysis of the process of atmospheric air water vapour condensation and an analysis of the resulting liquid phase evaporation on the shock wave. Calculations are performed using an in-house CFD code based on the solution of averaged Navier-Stokes equations supplemented with additional equations modelling the condensation process of water vapour contained in atmospheric air. Experiments are carried out using an in-house facility adapted for measurements of atmospheric air transonic flows.

Application of a single-fluid model for the steam condensing flow prediction

One of the results of many years of research conducted in the Institute of Power Engineering and Turbomachinery of the Silesian University of Technology are computational algorithms for modelling steam flows with a non-equilibrium condensation process. In parallel with theoretical and numerical research, works were also started on experimental testing of the steam condensing flow. This paper presents a comparison of calculations of a flow field modelled by means of a single-fluid model using both an in-house CFD code and the commercial Ansys CFX v16.2 software package. The calculation results are compared to inhouse experimental testing.

Experimental and numerical study on condensation in transonic steam flow

Abstract The present paper describes an experimental and numerical study of steam condensing flow in a linear cascade of turbine stator blades. The experimental research was performed on the facility of a small scale steam power plant located at Silesian University of Technology in Gliwice, Poland. The test rig of the facility allows us to perform the tests of steam transonic flows for the conditions corresponding to these which prevail in the low-pressure (LP) condensing steam turbine stages. The experimental data of steam condensing flow through the blade-to- blade stator channel were compared with numerical results obtained using the in-house CFD numerical code TraCoFlow. Obtained results confirmed a good quality of the performed experiment and numerical calculations.