This paper deals with active methods of flow control, especially synthetic jet flow control. A synthetic jet was used for flow control in the compressor blade cascade to reduce the vortex structure and reduce the value of the loss coefficients. The output slot of the synthetic jet actuator was situated on the side wall on the connecting line of the leading edges of the blades. The direction of the synthetic jet was perpendicular to the main flow. The synthetic jet excitation is more effective and more efficient than a steady blowing or suction, and its great advantage is zero mass flux supplied to, or taken from the main flow. A positive influence of the synthetic jet on the flow field was proved. The flow field was also visualized.

The paper deals with development and application the numerical model for solution of processes at combustion chamber of the thermal power plant boiler. Mathematical simulation is based on solution of physical and chemical processes occuring at burning pulverized coal in the furnace model. Three-dimensional flows, heat and mass transfer, chemical kinetics of the processes, effects of thermal radiation are considered. Obtained results give quantitative information on velocity distributions, temperature and concentration profiles of the components, the amount of combustion products including harmful substances. The numerical model becomes a tool for investigation and design of combustion chambers with high-efficiency and reliable operation of boiler at thermal power plants.

The paper deals with experimental and numerical study of flow structure in two-dimensional model of supersonic ejector. Schlieren pictures of flow structure were taken, static pressure distributions on side wall were measured and Fluent software to calculate the flow structure in supersonic ejector was used. For certain region of back pressure ratio Pb/P02 and stagnation pressure ratio of both streams P01/P02 the terminal shock wave is close to the trailing edge of the primary flow nozzle and a transonic instability occurs. The instability causes the movement of position of boundary layer separation, the structure of shock waves changes and all flow structure oscillates. The movie of these regimes during schlieren experiments was taken and relevant numerical modelling was performed.

Abstract.Complete description of all forces acting on a flying Beach Volleyball was made based on measurements in the wind tunnel. Forces (drag, lift and side force) were measured for different angle of attack  which varies from 0° to 47°. Velocity region was from 10 to 25 m/s and revolution region was from 0 to 12.5 rps. Moments (Roll, Yaw, Pitch) were detected. Results are described by means of non-dimensional numbers, such as Reynolds number Re, spin s, drag CD, lift CL and side force CS coefficients. Differences in results of CD, CL and CS were detected for various angle  and are further described in the article. Conclusions of the investigation can be utilized 1 st by ball producers for practical use in development, 2 nd for sport Methodist to build more exact methodology for Beach Volleyball, 3 rd in basic and applied aerodynamic research.

The paper deals with experimental and numerical results of investigation into supersonic and transonic flow past a two-dimensional model ejector. Results of optical measurements show a flow structure and flow parameter development in the entrance part of the mixing chamber of the ejector. Numerical results are obtained by means of both the straight solution of shock waves in supersonic flow field using classical relations of parameters of shock waves and the Fluent 6 program. Results of numerical solutions are compared with experimental pictures of flow fields. Flow structure development in the mixing chamber is analysed in detail.