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Projects / Programmes source: ARIS

Numerical and experimental analysis of the unsteady phenomena in the reversible pump-turbine

Research activity

Code Science Field Subfield
2.13.00  Engineering sciences and technologies  Process engineering   

Code Science Field
T000  Technological sciences   
Keywords
pump-turbine, efficiency, numerical methods, cavitation, pressure pulsation, model test
Evaluation (rules)
source: COBISS
Researchers (7)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  05388  PhD Dragica Jošt  Process engineering  Researcher  2008 - 2011  127 
2.  05389  PhD Andrej Lipej  Process engineering  Researcher  2008 - 2011  160 
3.  22275  Peter Mežnar  Process engineering  Researcher  2008 - 2011  23 
4.  24331  PhD Jure Ravnik  Process engineering  Researcher  2008 - 2011  497 
5.  13470  PhD Niko Samec  Process engineering  Researcher  2008 - 2011  644 
6.  06428  PhD Leopold Škerget  Process engineering  Head  2008 - 2011  1,007 
7.  12653  PhD Zoran Žunič  Process engineering  Researcher  2008 - 2011  112 
Organisations (2)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0263  Scotta Turboinštitut Turbine machines, Ltd  Ljubljana  5051584000  234 
2.  0795  University ob Maribor, Faculty of mechanical engineering  Maribor  5089638010  24,091 
Abstract
The research project is aimed at the numerical analysis of unsteady phenomena in pump-turbine (PT). The main accent will be put on the interaction of the transient numerical flow analysis in the complete flow passage of the pump-turbine power plant (PTPP) using unsteady computational models and experimental results obtained with the model testing. The comparison of the numerical and experimental results enables the development of efficient tools, which can be easily used in the development of PT for any desired operating point. The results of the research will ensure the constitution of a data base for further development of one-stage pump-turbines for wide range of specific rotational speeds and heads. The optimization of the geometrical shape must correspond to both the hydraulic and the stress demands regarding the static and dynamic stresses. The guide vanes of the pump-turbine would be optimized having in mind the stresses on the basis of the greatest measured static and dynamic stresses on the model, which would ensure realization of a prototype with high capacity of the whole units.
Significance for science
Research work in the area of numerical analysis of non-stationary phenomena require very different spatial and temporal orders of magnitude. This means that we have a very fine computational grids and very small time steps. All this leads to very long computational times. Using multiprocessor supercomputers, computational times can be reduced, but in some cases, a single calculation requires several weeks or even months to achieve a good result. For the industry, time of development is crucial. It is necessary to develop effective methods to reduce the overall numerical procedure. To achieve these goals the optimization of parallel computation on a large number of processors has been investigated, allowing us to using the supercomputer with 2048 processors installed in Turboinstitute. For the development of the science is a very important study of different turbulence models for numerical simulation of non-stationary phenomena, especially in the pumping regime, where the effect occurs difuzorskega very much turbulence, flow and return odleplanj flows. We analyzed the results obtained with different dvoenačbenimi models using wall functions and the so-called low Reynolds models. In certain cases Large Eddy Symualtion (LES) turbulence model has been used, which has proved to be very accurate, but is currently too time consuming for routine work on industrial projects. In the last part of the project unsteady phenomena using SAS-SST (Scale Adaptive Simulation - Shear Stress Model) was analysed and we found out that the turbulence model is not so time consuming like LES model, but enable very good results in comparison with model test. Also the detailed analysis using cavitation model was performed, where the local pressure is near vapour pressure. Because the cavitation is in fact two phase flow and usually ansteady, the CPU time for such cases is also very long.
Significance for the country
In industry a lot of numerical analysis and computer modelling are used in the development process. Virtual prototyping can reduce expensive, time consuming and energetic wasteful experimental methods. In some areas the complete characteristics can be predicted before any part of the product is produced. Important area where CFD is used in the development process is energetic, especially renewable energy sources. In the following decades in this area will be invested several hundred billions of EUR and Slovene industry can participate in some percentage of this business. The success depends on the quality of the new developed products. Using up to date hardware and software our industry can be competitive in the global market. It means also opportunity to increase employment. Turboinštitut d.d. has the most powerful supercomputer in Slovenia and in the region (SE Europe). Cluster building block is IBM BladeCenter H. Each BladeCenter contains fourteen server blades, LAN and InfiniBand switches. Each blade is equipped wluster ith two quad-core Intel Xeon processors L5520 2.26GHz 8MB L2 1066MHz/60W and 16GB PC2-5300 CL5 ECC DDR2 RAM. The results of the project group are important for the further development of the knowledge in the area of development and production of thydraulic machines. Slovenian industry can offer hydraulic machines world-wide and with this product can compete with the companies around the world. This is one of the area where Slovene industry can offer high level final product and just a few countries in the world have such technology on the same lavel. This means also opportunity to increase employment in this industry.
Most important scientific results Annual report 2008, final report, complete report on dLib.si
Most important socioeconomically and culturally relevant results Annual report 2008, final report, complete report on dLib.si
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