1. What is the Lift Coefficient for Symmetrical Airfoil?

The Lift Coefficient (C_L) is a dimensionless coefficient that relates the lift generated by a lifting body to the fluid density around the body, the fluid velocity and an associated reference area. For symmetrical airfoils using thin airfoil theory, the lift coefficient is directly proportional to the angle of attack.

2. How Does the Calculator Work?

The calculator uses the thin airfoil theory formula:

Where:

• \( C_L \) — Lift Coefficient (dimensionless)
• \( \pi \) — Archimedes' constant (approximately 3.141592653589793)
• \( \alpha \) — Angle of Attack (radians)

Explanation: This formula is derived from thin airfoil theory and provides the theoretical lift coefficient for a symmetrical airfoil at small angles of attack.

3. Importance of Lift Coefficient Calculation

Details: Accurate lift coefficient calculation is crucial for aircraft design, performance prediction, and understanding aerodynamic behavior of airfoils.

4. Using the Calculator

Tips: Enter the angle of attack in radians. The angle must be a non-negative value. For degrees conversion, remember that 1 degree = π/180 radians.

5. Frequently Asked Questions (FAQ)

Q1: What is thin airfoil theory?
A: Thin airfoil theory is a mathematical model that provides a way to calculate the lift and moment coefficients for thin airfoils at small angles of attack.

Q2: Why is the formula specifically for symmetrical airfoils?
A: Symmetrical airfoils have identical upper and lower surfaces, resulting in zero lift at zero angle of attack, which simplifies the lift calculation to this linear relationship.

Q3: What are typical lift coefficient values?
A: For symmetrical airfoils, C_L typically ranges from 0 to about 1.2-1.5 before stall occurs at higher angles of attack.

Q4: What are the limitations of thin airfoil theory?
A: The theory assumes small angles of attack, inviscid flow, and thin airfoils. It becomes less accurate at higher angles of attack and for thicker airfoils.

Q5: How does this compare to real-world airfoil performance?
A: While thin airfoil theory provides a good theoretical foundation, real airfoils may have slightly different lift characteristics due to viscosity, thickness, and other real-world effects.