GATE 2026 AE – Question 34
The vortex shedding frequency behind a landing gear model is found to be 50 Hz when tested in a wind tunnel operating at 5 m/s. If the actual landing gear size is 10 times that of the model, and it is designed to operate at 50 m/s, then the expected vortex shedding frequency behind it is ________ Hz (rounded off to the nearest integer).
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Correct answer: 50
Explanation
The Strouhal number $St = \frac{fL}{V}$ is the same for dynamically similar flows. Then $f_2 = f_1 \frac{L_1}{L_2}\frac{V_2}{V_1} = 50 \times \frac{1}{10} \times \frac{50}{5} = 50$ Hz.