In the present study, flow visualizations and quantitative measurements around a NACA0012 airfoil are performed under air and CO
2 operation modes. A diaphragmless shock tube system is used for a high-subsonic airfoil testing. This system has the possibility of efficient aerodynamic experiments as an intermittent wind tunnel. A point diffraction interferometry (PDI) is used for a flow measurement technique. Moreover, the comparison with numerical results by the OpenFOAM is performed. The driver tube of this shock tube is the circular cross section with a diameter of 150mm. The driven tube is the rectangular cross section with a width of 60mm and a height of 150mm. The hot gas Mach number (uniform high-subsonic flow condition) is
M2 = 0.65. The angle of attack is α = 0° and 2°, and the range of the Reynolds number is
Re = 1.7–7.4 × 10
5. The results of the present study are as follows. In the present Reynolds numbers, if the shock wave does not generate, the shock tube airfoil flows of CO
2 mode showed almost the same trend as the case of air mode quantitatively. The difference of operation gas was confirmed when the shock wave generated on the airfoil surface. In the high-subsonic flow, the pressure coefficients
Cp by the PDI are in relatively agreement with the CFD results. The numerical results by the OpenFOAM give useful results for the comparison with aerodynamic data. Therefore, this shock tube system with a PDI measurement technique is considered as one of useful facilities for different operational modes.
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