This paper presents a very effective interference technique for the sensing and researching of compressible fluid flow in a wind tunnel facility. The developed technique is very sensitive and accurate, yet easy to use under conditions typical for aerodynamic labs, and will be used for the nonintrusive investigation of flutter in blade cascades. The interferometer employs a high-speed camera, fiber optics, and available “of-the-shelf” optics and optomechanics. The construction of the interferometer together with the fiber optics ensures the high compactness and portability of the system. Moreover, single-shot quantitative data processing based on introducing a spatial carrier frequency and Fourier analysis allows for almost real-time quantitative processing. As a validation case, the interferometric system was successfully applied in the research of supersonic compressible fluid discharge from a narrow channel in a wind tunnel. Density distributions were quantitatively analyzed with the spatial resolution of about $50 \mathsf{\mu }\mathrm{m}$. The results of the measurement revealed important features of the flow pattern. Moreover, the measurement results were compared with Computational Fluid Dynamics (CFD) simulations with a good agreement.

Focus of this paper is aerodynamic investigation of tie-boss stabilization devices for extremely long rotor blades. This investigation covered measurements on multiple blade cascades and computational fluid dynamics (CFD) simulation of the flow past these cascades. Conclusions were drawn from results of the measurements and CFD and from the knowledge of prior investigation of the used blade cascade. Main focus of this paper is to describe influence of a tie-boss stabilization device on flow field in interblade channel. Tie-boss with more massive shape proved to cause lesser losses, while tie-boss with a tailored trailing edge showed lesser influence on flow turning.

Aerodynamic experimental measurements and numerical simulations carried out on a model of a high-pressure valve assembly used for a nozzle governing of a turbine with 135 MW output are described in this paper. Aim of the study is to investigate effects of control valve’s strainers on pressure losses and unsteadiness in the flow field thus its effect to undesirable flow fluctuations

A new design of an intercept valve assembly of the intermediate-pressure turbine part of greater power output is investigated in terms of pressure losses and flow fluctuations by using measurement on an experimental valve model. In addition, numerical simulations are used to further clarify measured phenomena. For such valve assemblies, it is important to exactly predict pressure

With the increasing share of renewable power resources turbomachines need to be operated under a wider range of operating conditions including highly off-design regimes. Under such regimes an undesirable phenomenon of blade flutter might occur and possibly destroy the machine. To prevent this, intensive research is conducted by research teams worldwide. Blade flutter research program at the Institute of Thermomechanics of the Czech academy of sciences (IT CAS) mainly aims to advance experimental techniques for investigation of sonic and transonic blade flutter. For this purpose, the new sophisticated test facility was designed and manufactured. As part of the design process, the CFD computations were conducted in order to investigate the flow field in the test facility. This paper presents results of these computations with detailed analysis of flow structures occurring during the air flow through the stationary blade cascade.