1. What is a Prismatic Coefficient Calculator?

Definition: This calculator determines the prismatic coefficient, a dimensionless value that describes the fullness of a ship's hull form.

Purpose: It helps naval architects and marine engineers evaluate hull efficiency and resistance characteristics.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( C_p \) — Prismatic coefficient (dimensionless)
• \( V \) — Displaced volume (m³)
• \( A_m \) — Midship section area (m²)
• \( L \) — Length (m)

Explanation: The displaced volume is divided by the product of midship area and length to determine hull fullness.

3. Importance of Prismatic Coefficient

Details: The coefficient affects resistance, power requirements, and efficiency. Lower values indicate finer hulls with less resistance at high speeds.

4. Using the Calculator

Tips: Enter the displaced volume in m³, midship section area in m², and length in m. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical prismatic coefficient range?
A: Most ships range between 0.55 (fine hulls) to 0.85 (full hulls), with cargo ships typically 0.70-0.78.

Q2: How does prismatic coefficient affect performance?
A: Lower coefficients generally mean less resistance at high speeds but more at low speeds. Higher coefficients are better for slow, full-bodied ships.

Q3: What length measurement should be used?
A: Use the length between perpendiculars (LBP) or waterline length (LWL), but be consistent in your calculations.

Q4: How do I find the displaced volume?
A: This can be calculated from hydrostatic data or by multiplying the mass of displaced water by its density.

Q5: What's the relationship with block coefficient?
A: Prismatic coefficient equals block coefficient divided by midship section coefficient (C_p = C_b/C_m).