Precision Circular Cylinder Model (D = 25 mm)
Rigid, polished brass cylinder spanning the entire wind tunnel test section width.
Aerospace & Aeronautical Engineering / Cylinder Vortex Shedding
FREE TO EXPLORELABORATORY 10 · AEROSPACE & AERONAUTICAL ENGINEERING
Crossflow Around a Circular Cylinder and von Kármán Vortex Shedding
Measure the vortex shedding frequency f_s behind a circular cylinder across flow velocities to determine the non-dimensional Strouhal number St. Explore interactive wind tunnel simulation, flight dynamics, and aerospace engineering telemetry.
AERODYNAMICS · PROPULSION · FLIGHT DYNAMICS
Your virtual aerospace engineering laboratory.
SHEDDING FREQUENCY F_S—
FLIGHT & TEST CELL TELEMETRY
Ready to sample with V_inf/D = 200.0 s^-1.
Adjust V_inf/D, then execute aerospace trial.
Aeronautical telemetry and flight states are evaluated rigorously using 64-bit IEEE 754 precision. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity aerodynamic modeling.
Aeronautical assumptions and boundary condition limits
Strouhal number invariance (St approx 0.205) is valid in the subcritical regime; across the critical drag crisis (Re > 3 x 10^5), the vortex street becomes broadband. Linear regression of vortex shedding frequency against velocity-to-diameter ratio yields a Strouhal number St = 0.2050 with R^2 > 0.999999.
Aeronautical apparatus & wind tunnel sensors.
Single-Sensor Constant Temperature Hot-Wire Probe
Tungsten wire sensor (5 micrometer diameter) placed 2.5 D downstream and 1.0 D offset in the shear layer.
CTA Hot-Wire Anemometer Bridge Chassis
High-frequency feedback bridge operating at 100 kHz frequency response for velocity fluctuation tracking.
Digital FFT Spectrum Analyzer
Computes real-time power spectral density (PSD) to detect dominant vortex shedding peak frequency f_s.
Subsonic Wind Tunnel Test Section
Provides smooth airspeed from V_inf = 3.75 m/s to 15.0 m/s with turbulence intensity Tu < 0.1%.
Pitot-Static Speed Monitor
Measures free-stream airspeed V_inf with 0.05 m/s resolution.
FOLLOW THE METHOD
A reason behind every step.
Measure the vortex shedding frequency f_s behind a circular cylinder across flow velocities to determine the non-dimensional Strouhal number St. Standardized parameter settings: 150.0, 200.0, 300.0, 400.0, 500.0, 600.0 s^-1.
01
Cylinder Alignment and Hot-Wire Setup
Mount the D = 25 mm cylinder horizontally and position the hot-wire sensor at x/D = 2.5, y/D = 1.0 in the active vortex shedding path.
02
Hot-Wire Sensor Calibration
Execute in-situ King's Law velocity calibration of the hot-wire anemometer against reference Pitot-static airspeeds.
03
Baseline Shedding Frequency Measurement
Set wind tunnel speed to establish V_inf / D = 150 s^-1 (V_inf = 3.75 m/s), acquire velocity time series, and compute FFT spectrum.
04
Velocity-to-Diameter Stepping
Step the velocity through V_inf / D = 200, 300, 400, 500, and 600 s^-1 (corresponding to V_inf up to 15.0 m/s).
05
Peak Spectral Frequency Extraction
Identify the sharp primary spectral peak f_s on the power spectrum for each airspeed setting, recording peak frequency in Hz.
06
Strouhal Number Linear Regression
Plot shedding frequency f_s versus V_inf / D, perform linear regression to determine slope St, and verify subcritical Strouhal invariance.
YOUR NOTEBOOK · 0 OBSERVATIONS
Turn measurements into aerodynamic insight.
Points are your recorded observations. The solid regression line validates Cylinder Vortex Shedding mathematical scaling.
LINEAR REGRESSION FIT · y = mx + b
f_s = St \cdot \left(\frac{V_\infty}{D}\right) \implies f_s = m \cdot \left(\frac{V_\infty}{D}\right) + b
| # | Velocity to Diameter Ratio (s^-1) | Shedding Frequency f_s (Hz) | Velocity-to-Diameter Ratio V_inf / D (s^-1) | Vortex Shedding Frequency f_s (Hz) | Remove |
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