Flutter methodology using reduced order aeroelastic model
Prasad, Chandra Shekhar; Pešek, Luděk; Šnábl, Pavel
2021 - anglický The present research project is focused on development of fast and efficient numerical method based on reduced order aeroelastic method (ROAM) for modeling and analysis of \nclassical flutter in the low pressure (LP) stage steam turbine blade. Stability diagram such as aerodynamic damping (AD) of aeroelasticity of cascade of 3D turbine blades used as a prime \ncharacterization factor. In the calculation of the S-curve/AD, the problem of classical flutter formation associated with running waves is considered here. Running waves is simulated by \nthe inter-blade phase shift of the blades in the cascade. Panel method based boundary element flow solver is employed for calculation of unsteady aerodynamic forces. This method is good \ncompromise of speed and accuracy for the estimation of the stability of the blades on a classical flutter. One way loose coupling technique between PM based flow solver and the structural \nmodel. For the structural part modal model synthesis (MMS) method is adopted in the ROAM solver. MMS is adopted to further reduced the computational cost. The ROAM simulated AD \nand pressure distribution over blade is compared high fidelity CFD data on real blade geometry provided by Doosan Skoda Power s.r.o. Furthermore, the ROAM results are also compared \nwith experimentally obtained results on two different linear cascade. The ROAM model shows good agreement with linear cascade results, however, there is noticeable discrepancy with real blade CFD results. Klíčová slova: reduced order model (ROM); classical flutter; steam turbine blade; panel method Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Flutter methodology using reduced order aeroelastic model

The present research project is focused on development of fast and efficient numerical method based on reduced order aeroelastic method (ROAM) for modeling and analysis of \nclassical ...

Prasad, Chandra Shekhar; Pešek, Luděk; Šnábl, Pavel
Ústav termomechaniky, 2021

Paleomagnetic research of fill at T1 north portal (Rhinoceros site) – 2TDK Slovenia. Final Report
Bosák, Pavel; Zupan Hajna, N.; Kdýr, Šimon; Pruner, Petr; Švara, A.
2020 - anglický Klíčová slova: karst sediments; paleomagnetism; magnetostratigraphy; railway construction; Classical Karst; Slovenia Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Paleomagnetic research of fill at T1 north portal (Rhinoceros site) – 2TDK Slovenia. Final Report

Bosák, Pavel; Zupan Hajna, N.; Kdýr, Šimon; Pruner, Petr; Švara, A.
Geologický ústav, 2020

Visual Images Segmentation based on Uniform Textures Extraction
Goltsev, A.; Gritsenko, V.; Húsek, Dušan
2020 - anglický A new effective procedure for partial texture segmentation of visual images is proposed. The procedure segments any input image into a number of non-overlapping homogeneous ne-grained texture areas. The main advantages of the proposed procedure are as follows. It is completely unsupervised, that is, it processes the input image without any prior knowledge of either the type of textures or the number of texture segments in the image. In addition, the procedure segments arbitrary images of all types. This means that no changes to the procedure parameters are required to switch from one image type to another. Another major advantage of the procedure is that in most cases it extracts the uniform ne-grained texture segments present in the image, just as humans do. This result is supported by series of experiments that demonstrate the ability of the procedure to delineate uniform ne-grained texture segments over a wide range of images. At a minimum, image processing according to the proposed technique leads to a signficant reduction in the uncertainty of the internal structure of the analyzed image. Klíčová slova: Texture feature; Texture window; Homogeneous ne-grained texture segment; Texture segment extraction; Texture segmentation Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Visual Images Segmentation based on Uniform Textures Extraction

A new effective procedure for partial texture segmentation of visual images is proposed. The procedure segments any input image into a number of non-overlapping homogeneous ne-grained texture areas. ...

Goltsev, A.; Gritsenko, V.; Húsek, Dušan
Ústav informatiky, 2020

Measurements on TR-W-1 Cascade
Luxa, Martin; Šimurda, David
2020 - anglický The research report contains experimetal data from optical and pneumatic measurements on transonic profile cascade with linear part of suction side downstream the sonic line, which is intended for the rotor wheal of a last stage of steam turbine Klíčová slova: transonic flow; steam turbine; profile cascade Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Measurements on TR-W-1 Cascade

The research report contains experimetal data from optical and pneumatic measurements on transonic profile cascade with linear part of suction side downstream the sonic line, which is intended for the ...

Luxa, Martin; Šimurda, David
Ústav termomechaniky, 2020

Measurements on TR-W-2 Cascade
Luxa, Martin; Šimurda, David
2020 - anglický The research report contains experimetal data from optical and pneumatic measurements on transonic profile cascade with non-linear part of suction side downstream the sonic line, which is intended for the rotor wheal of a last stage of steam turbine. Klíčová slova: transonic flow; steam turbine; profile cascade Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Measurements on TR-W-2 Cascade

The research report contains experimetal data from optical and pneumatic measurements on transonic profile cascade with non-linear part of suction side downstream the sonic line, which is intended for ...

Luxa, Martin; Šimurda, David
Ústav termomechaniky, 2020

Measurements on KR-D-3 Blade Cascade
Šimurda, David; Hála, Jindřich; Radnic, Tomáš
2020 - anglický This report contains result and evaluation of aerodynamic measurements conducted on a subsonic compressor blade cascade. Klíčová slova: compressor blade cascade; experiment; subsonic flow; transonic flow; AVDR Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Measurements on KR-D-3 Blade Cascade

This report contains result and evaluation of aerodynamic measurements conducted on a subsonic compressor blade cascade.

Šimurda, David; Hála, Jindřich; Radnic, Tomáš
Ústav termomechaniky, 2020

Region of interest tomography
Vopálenský, Michal; Kumpová, Ivana
2020 - anglický During standard tomographic process, the acquisition of tomographic data (projections) is performed with geometric adjustment of the tomographic assembly ensuring that the projection of the entire width of the examined object fits onto the detector during the full object rotation. Because of the limited width of the detector, this approach has a limited maximum achievable resolution for the given specimen diameter. It is possible to make higher magnification, but then the projections do not fit onto the detector, which causes certain problems during the reconstruction, but allows achieving of higher resolution in the always-visible region of the object (the region of interest). The research was focused on evaluation of ROI tomography approach on the TORATOM tomograph. Klíčová slova: X-ray computed tomography; resolution; Region-of-Interest tomography Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Region of interest tomography

During standard tomographic process, the acquisition of tomographic data (projections) is performed with geometric adjustment of the tomographic assembly ensuring that the projection of the entire ...

Vopálenský, Michal; Kumpová, Ivana
Ústav teoretické a aplikované mechaniky, 2020

Optical and Pneumatic Measurement on TR-U-10 Cascade
Luxa, Martin; Šimurda, David
2020 - anglický The report contains results and evaluation of conducted optical (interferometry and schlierren technique) and pneumatic measurements on the third variant of the new tip section, intended for long rotor blade. Klíčová slova: transonic flow; tip section; steam turbine Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Optical and Pneumatic Measurement on TR-U-10 Cascade

The report contains results and evaluation of conducted optical (interferometry and schlierren technique) and pneumatic measurements on the third variant of the new tip section, intended for long ...

Luxa, Martin; Šimurda, David
Ústav termomechaniky, 2020

Optical and Pneumatic Measurements on TR-U-9A Cascade
Luxa, Martin; Šimurda, David
2020 - anglický The report contains results and evaluation of conducted optical (interferometry and schlieren technique) and pneumatic measurements on the eroded variant of the new tip section, intended for long rotor blade. Klíčová slova: transonic flow; experimental aerodynamic; steam turbine Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Optical and Pneumatic Measurements on TR-U-9A Cascade

The report contains results and evaluation of conducted optical (interferometry and schlieren technique) and pneumatic measurements on the eroded variant of the new tip section, intended for long ...

Luxa, Martin; Šimurda, David
Ústav termomechaniky, 2020

Globalization of science: evidence from authors in academic journals by country of origin
Macháček, Vít
2020 - anglický Klíčová slova: globalization of science; academic journals Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR. Globalization of science: evidence from authors in academic journals by country of origin

Macháček, Vít
Národohospodářský ústav, 2020