No abstract

The blown down wind tunnel tube has been developed. It provides a high degree of air flow laminarization. The uniqueness of this design is the presence of a system of air vortices destruction. This system contains a complex of metal grids, honeycomb straightener and contraction nozzle. The combination of these elements allows for low turbulence level and promote the air flow relative to its axis. The complex of measuring equipment for the establishment of operational characteristics in the test section has been performed. A four-channel probe has been developed to analyze the total pressure and air flow velocity in the measuring tunnel area. The design of this probe makes possible to analyze the boundary layers of air flow in a wind tunnel. The corrective algorithm of recombination for the obtained data and software for their analysis is developed. A prerequisite for developing an algorithm for the recombination of the obtained data and their subsequent visualization is the idea of sectoral analysis and averaging of the data of common areas of the measuring area. Besides the developed algorithm, the correction function for leveling the aerodynamic resistance of the design of the four-channel probe was included. Whereas it approaches the nozzle of static pressure, there is a distortion of the real data distribution on each of the probe tube. To confirm the adequacy of the developed algorithm and the correct functioning of the software developed on its basis, a series of experimental studies was conducted, which were based on the measurement of total pressure when placing objects that create aerodynamic resistance in the measuring section. A profile analysis of the data allowed to visualize correctly the distribution of total pressure around the investigated bodies, even in the place of its sharp difference.

This work aimed to investigate the turbulence characteristics behind different parts of the wind turbine blade. Airfoils S807, S813, S817, and S803, which characterize the shape of the blade at different lengths, were selected for estimation. During the experiment, the chord-based Reynolds number was 2.6×105, while the angle of attack was zero. Measuring crosssections were placed behind the trailing edge at x·c-1≈0.2, 0.4 and 1.0. For the determination flow topology, we used a Hotwire anemometry with a split fiber probe 55R55 and a miniature X-wire probe 55P64. The obtained data allowed us to determine and compare the evolution of the wake behind different types of airfoils in streamwise and spanwise directions. Thus, the largest and smallest velocity deficit located behind S817 and S803 airfoils, respectively. This trend is also evident in the Normalized Reynolds shear stress distributions. Finally, we determined the spectrum and calculated the Integral length scale, the Taylor and Kolmogorov microscale of turbulent flow. According to the results, profile S817 contributes to the formation of a flow with a large scale of turbulence, while the S803 is contrary.

The airfoil NACA 64-618 is realized by using two levels of quality: first the theoretical profile is printed on a 3D printer in a direct, “naive” way, this geometry has been scanned by using 3D scanner and based on the deviations, a better model has been processed. The flow within the turbulent wake is measured by using Particle Image Velocimetry (PIV) technique at two velocities separated by one order of magnitude.

Across industries, the demand for the ability to analyze components in operation and make decisions on repair based on the data obtained is growing rapidly. There is the potential to ensure safer operations while saving the cost of unnecessary new parts. A quick and relatively inexpensive method is a 3D scanner - the device that can scan a real component and create an accurate 3D model. For stationary cases - inspecting parts or assemblies - these are already established methods. In contrast, measurement of vibrations and deformations in operation is still not widespread and for turbomachinery, it can be a new direction of development.