境界層の乱流遷移におけるトリッピングワイヤ効果とワイヤ後流の測定

概要

論文の詳細を見る
Experimental studies were performed to investigate the effect of a tripping wire on the boundary-layer transition over a 15 degree wedge in an external free stream. Turbulence measurements were carried out in the range from the wake of the wires to the laminar-turbulent transition region. The results indicated that the tripping wire becomes effctive at the wire Reynolds number R-k (=U_∞x_k/ν) larger than R_<k1> where R_<k1>=570 (z_k/k) -4.3×10^3, and that the transition Reynolds number R_t (=U_∞x_t/ν) at the most effective condition is given as the formula R_t =1.06 R_k+1.33×10^4, in which U_∞ denotes the free stream velocity, x_k and x_t the location of the wire and the transition point measured from the apex of the wedge, respectively, k the wire diameter andνthe kinematic viscosity of the fluid. The Reynolds number in the experiments ranged from U_∞x_k/ν=(0.09-2.0) ×10^5 and x_k/k=25 to 200.
1988-12-25