PSI - Issue 72

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

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75,000 (Özkan, 2016) and its cost-effectiveness (Lim, 2012). The visualization will be achieved by creating smoke lines in the flow field through the generation of smoke by the combustion of hydrocarbon-based machine oil (paraffinic oil is typically utilized) with the assistance of an electric current on a wire positioned in front of the EDF engines. The flow was instantaneously visualized with the aid of a digital camera (30 fps successive photo shooting, 60 fps video shooting). The diameter of the chromium nickel wire is recommended to be 0.2 mm in the literature (Hamakawa et al., 2008; Ezersky et al., 2010; Deb et al., 2020). 1.1. The objective and the experimental setup The objective of smoke wire flow visualization is to observe the behavior and trajectory of smoke lines (Figure 1). However, it would not be feasible without a specific thrust. For this experiment, an electric ducted fan (EDF) controlled by an electronics speed controller (ESC) was employed, directed at a specific distance from the air openings of the Coanda surfaces (Figure 2). The EDF was utilized in this experiment at a power level of 7% of the maximum thrust. The resulting thrust generated a notable movement of the smoke lines.

Fig. 1. Trajectory of smoke lines around a Coanda surface

Fig. 2. A snapshot of the experimental setup.