摘要
In this study, we experimentally investigate the effects of mainstream turbulence intensity (<em>T<sub>i</sub></em>) on a leading-edge separation bubble under low-Reynolds number (<em>Re<sub>c</sub></em>) conditions range of 2.0 × 10<sup>4</sup> to 6.0 × 10<sup>4</sup>. We used a flat plate to fix a separation point at the leading edge. Also, we visualized the behavior of the leading-edge separation bubble using the smoke wire technique and Particle Image Velocimetry (PIV) measurement. Furthermore, we measured the effect of <em style="white-space:normal;">T<sub>i</sub></em> on the turbulent transition process in the separated shear layer using a hot-wire anemometer. The results indicate that the bypass transition for large <em style="white-space:normal;">T<sub>i</sub></em> causes the turbulent transition, and so accelerates the reattachment of the separated shear layer. The results show that the bypass transition promotes the reattachment of the separated shear layer to maintain the leading-edge separation bubble on the upper surface even at high angles of attack, increasing the stall angle.
In this study, we experimentally investigate the effects of mainstream turbulence intensity (<em>T<sub>i</sub></em>) on a leading-edge separation bubble under low-Reynolds number (<em>Re<sub>c</sub></em>) conditions range of 2.0 × 10<sup>4</sup> to 6.0 × 10<sup>4</sup>. We used a flat plate to fix a separation point at the leading edge. Also, we visualized the behavior of the leading-edge separation bubble using the smoke wire technique and Particle Image Velocimetry (PIV) measurement. Furthermore, we measured the effect of <em style="white-space:normal;">T<sub>i</sub></em> on the turbulent transition process in the separated shear layer using a hot-wire anemometer. The results indicate that the bypass transition for large <em style="white-space:normal;">T<sub>i</sub></em> causes the turbulent transition, and so accelerates the reattachment of the separated shear layer. The results show that the bypass transition promotes the reattachment of the separated shear layer to maintain the leading-edge separation bubble on the upper surface even at high angles of attack, increasing the stall angle.
作者
Katsuya Kajiwara
Masayuki Anyoji
Katsuya Kajiwara;Masayuki Anyoji(Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Fukuoka, Japan)
