PSI - Issue 72

Emre Kara et al. / Procedia Structural Integrity 72 (2025) 85–90

89

Fig. 6. Step-by-step close-ups of the smoke wire visualization of the flow dynamics of FTV system based on Coanda effect: (a) First formation of the smoke, (b) burning oil on the wire, (c) adhesion behavior of smoke to a surface in the absence of thrust, (d) smoke after the EDF fan has been started, (e) orientation of smoke by Coanda effect after thrust has been applied and (f) full visualization of the Coanda effect. The results of the flow visualization are presented in Figure 6 that shows the formation of smoke. Shortly after their formation (Fig. 6a), the smoke follows the curved surface (Fig. 6b), even without any external thrust. Only a small portion moves in the opposite direction. It is also evident that the smoke lines initially choose the direction of the wire (Fig. 6c), following it before colliding with the surface and then proceeding along their own path along the surface. This can be explained by the absence of external forces acting on the smoke at that point. After the activation of the ESC fan, a clear change in direction of the lines that did not initially flow along the surface is observed (Fig. 6d). The thrust generated by the fan causes the smoke to move in the same direction as the airflow. As expected, the smoke lines precisely follow the direction of the curved surface, attributed to the Coanda effect. Figure 6e illustrates the orientation of smoke after thrust has been applied. Finally, Figure 6f shows the full visualization of the Coanda effect.