Free Stream Velocity Given Strouhal Number Calculator

Formula Used:

\[ V_{\infty} = \frac{n \times D_{vortex}}{S} \]

Frequency of Vortex Shedding (n):

Diameter of Cylinder with Vortex (D_vortex):

Strouhal Number (S):

Freestream Velocity of Fluid (V_∞):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Free Stream Velocity Given Strouhal Number Calculator?

The Free Stream Velocity Given Strouhal Number Calculator estimates the freestream velocity of fluid based on vortex shedding frequency, cylinder diameter, and Strouhal number. It is commonly used in fluid dynamics to analyze oscillating flow patterns around cylindrical structures.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ V_{\infty} = \frac{n \times D_{vortex}}{S} \]

Where:

\( V_{\infty} \) — Freestream Velocity of Fluid (m/s)
\( n \) — Frequency of Vortex Shedding (Hz)
\( D_{vortex} \) — Diameter of Cylinder with Vortex (m)
\( S \) — Strouhal Number (dimensionless)

Explanation: The Strouhal number relates the vortex shedding frequency to the fluid velocity and cylinder diameter, providing a dimensionless parameter for characterizing oscillating flow mechanisms.

3. Importance of Free Stream Velocity Calculation

Details: Accurate calculation of freestream velocity is essential for understanding fluid-structure interactions, predicting vortex-induced vibrations, and designing structures that are resistant to flow-induced oscillations in various engineering applications.

4. Using the Calculator

Tips: Enter the frequency of vortex shedding in Hz, the diameter of the cylinder in meters, and the Strouhal number (dimensionless). All values must be positive and valid for accurate results.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range of Strouhal numbers for circular cylinders?
A: For circular cylinders in cross-flow, the Strouhal number typically ranges from 0.18 to 0.22 for Reynolds numbers between 300 and 10^5.

Q2: How does Reynolds number affect vortex shedding?
A: The Reynolds number influences the flow regime and vortex shedding characteristics. Different Reynolds number ranges produce different wake patterns and Strouhal numbers.

Q3: Can this calculator be used for non-cylindrical structures?
A: The formula is specifically derived for cylindrical structures. For other shapes, different relationships between vortex shedding frequency and flow velocity may apply.

Q4: What factors can affect the accuracy of this calculation?
A: Surface roughness, end conditions, turbulence intensity, and three-dimensional flow effects can all influence the accuracy of vortex shedding predictions.

Q5: How is vortex shedding frequency typically measured?
A: Vortex shedding frequency can be measured using various techniques including hot-wire anemometry, pressure transducers, flow visualization, or laser Doppler velocimetry.