Penyelidikan eksperimen pengukuran tekanan yang tidak stabil dari airfoil 2D NACA 0018 yang berosilasi dalam gerakan pitch dilakukan dengan menggunakan transduser tekanan pada terowong angin litar terbuka. Dalam kes kajian, ujian terowong angin dilakukan dalam rejim penerbangan rendah (𝑅𝑒 = 68474 dan 𝑅𝑒 = 136948) di pelbagai sudut serangan. Ujian statik dilakukan dan data diperolehi sebagai garis dasar untuk analisis lanjut. Tekanan permukaan atas permukaan atas dan atas lelayang airfoil diukur dan seterusnya digunakan untuk mengira pekali tekanan. Berkenaan dengan tujuan analisis, bagi ujian statik, graf pekali tekanan terhadap 𝑥 / 𝑐 sudut serangan 2 °, 12 ° dan 18 ° pada halaju aliran bebas 5 𝑚 / 𝑠 dan 10 𝑚 / 𝑠 telah diperiksa manakala untuk ujian dinamik, representasi 3D pengedaran tekanan dengan 𝑥 / 𝑐 dan masa untuk melonjakkan amplitud 5 ° -15 ° dan 10 ° -20 °, kekerapan pitch 3 𝐻𝑧 dan halaju aliran bebas 5 𝑚 / 𝑠 dan 10 𝑚 / 𝑠 telah diplot.
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An experimental investigation of the unsteady pressure measurement of a 2D NACA 0018 airfoil oscillating in pitch motion was performed by using pressure transducers at open-circuit wind tunnel. In the case of study, the wind tunnel testing was conducted in low flight regimes (𝑅𝑒 = 68474 and 𝑅𝑒 = 136948) at various angles of attack. Static test was performed and the data were obtained as baseline for further analysis. Surface pressure over the lower and upper surfaces of the airfoil was measured and was subsequently used to compute the pressure coefficient. With regard to analysis purpose, for static test, the graphs of pressure coefficient against 𝑥/𝑐 of 2°, 12° and 18° angle of attack at free-stream velocities of 5 𝑚/𝑠 and 10 𝑚/𝑠 were plotted whereas for dynamic test, the 3D representations of pressure distribution with 𝑥/𝑐 and time for pitching amplitude of 5°-15° and 10°-20°, pitching frequency of 3 𝐻𝑧 and free-stream velocities of 5 𝑚/𝑠 and 10 𝑚/𝑠 were plotted.
Unsteady pressure measurement of NACA 0018 undergoing pure pitching motion at different pitch amplitudes / Tong Chee Kent