Specifics of application of videogrammetric system Vic-3D in aerodynamic experiment

The main objective of this work was testing a possibility of application of commercial videogrammetric system Vic-3D for measuring position and deformation of the aircraft model and its elements in an industrial the TsAGI transonic wind tunnel T-128. The object of research was a model of passenger aircraft with a wingspan of 2010 mm, fixed on the rear sting. The Vic-3D system used for measuring the position and deformation of the aircraft model was applied for the runs with and without flow at the pitch angles range from − 3 to +12 degrees. Model was tested in wind tunnel up to Mach number M = 0.853. An algorithm of working with the Vic-3D system was described in the article, some specifics of obtained results were underlined. An additional program to derive bend and twist deformations of a wing was developed. Results of an experiment were given, errors and inaccuracy were analyzed. Recommendations for using the system Vic-3D in an aerodynamic experiment were given.

Numerical Simulation of Disturbance Evolution in the Supersonic Boundary Layer over an Expansion Corner

Abstract— The linear and nonlinear stages of disturbance development in the supersonic boundary layer over a 10° expansion corner is investigated numerically within the framework of Navier—Stokes equations for Mach number 3. The effect of sudden flow expansion on the disturbance evolution is analyzed. The flow stabilization effect observable in the aerodynamic experiment is also discussed.

Experimental Evaluation for The Feasibility of Test Chamber in The Open-Loop Wind Tunnel

The test chamber in an open-loop wind tunnel is a critical part for aerodynamic experiment. The study aims to assess the feasibility of the new design of test chamber for open–loop wind tunnel by studying the fluid characteristic and the average pressure in the test chamber. The study is done by a series experimental test for the test chamber. From experimental test, the downstream velocity in the test chamber is increased from 8.9 m/s to 12.72 m/s where the pressure gradient is ranging from 6.19 to 8.398 atm with the overall turbulence intensity for the test chamber is 0.749%. According to the results, the designed open-loop wind tunnel is acceptable to use for an aerodynamic test.

The influence of turbulence on the efficiency and reliability of combustion chamber of the gas turbine

The article presents the research results related to the influence of turbulence on the efficiency of the combustion chamber of gas turbine. An artificial increase in the intensity of turbulence is considered as a way to improve the formation of a fuel-air mixture. Turbulent flow is formed due to the installation of guide swirlers at the entrance to the device for creating a fuel-air mixture - a micro module. The angle of rotation of the swirler blades is selected. Theoretical research, mathematical software modeling, as well as an aerodynamic experiment have been carried out. As a result, design solutions are provided that significantly increase the efficiency and reliability of the gas turbine combustion chamber. In the course of the study, guide vanes were selected, and their design was established. The recommended swing angle of the swirler guide vanes is 40?. The recommended depth of the fuel injector inside the chamber is 1.0 gauge.

Investigation of the Secondary Crossflow at the Rectangular Exit of a Low-Speed Sectioned Contractive Wind Tunnel

The low-speed rectangular exit wind tunnel with sectioned contraction is widely used. The secondary flow vortices are found at contraction exit, which would lead to the non-uniform boundary layer and influence the aerodynamic experiment accuracy. In this paper, experimental and numerical approaches are adopted so as to clarify reasons for the formation of the secondary crossflow occurring at contraction exit and take measures to control it. The conclusions can be gotten as: the secondary crossflow is formed and developed in the second (rectangular-to-rectangular) contraction, and the first (circular-to-rectangular) contraction promote the secondary flow vortices to migrate to the middle of flow field to a certain extent; the formation of the secondary crossflow is related to the static pressure gradient in the contraction. Based on the mechanism analysis results, several methods aimed to control the secondary crossflow are proposed and verified, the results can be concluded as: in terms of the rectangular-to-rectangular contraction that contracts along one direction, it is difficult to effectively control the secondary crossflow just by optimizing contraction curves and contraction ratios, while adopting the boundary layer suction can significantly improve the boundary layer uniformity; if the rectangular-to-rectangular contraction contracts in two directions, such secondary crossflow can be well controlled.