1. What is a Surface Drive Propeller Calculator?

Definition: This calculator estimates the torque generated by a surface drive propeller based on power input and rotational speed.

Purpose: It helps marine engineers, boat designers, and propeller manufacturers determine the torque characteristics of surface-piercing propellers.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( T \) — Torque (Newton-meters, Nm)
• \( P \) — Power (Watts, W)
• \( n \) — Rotational speed (revolutions per second, rev/s)
• \( \pi \) — Mathematical constant Pi (~3.1416)

Explanation: The power is divided by the product of 2π and rotational speed to calculate the torque output.

3. Importance of Torque Calculation

Details: Proper torque estimation ensures correct propeller sizing, shaft strength requirements, and optimal engine performance in marine applications.

4. Using the Calculator

Tips: Enter the power in Watts and rotational speed in revolutions per second (rev/s). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical power range for marine propellers?
A: Small boats might use 5-50 kW, while large vessels can require 500 kW to several MW.

Q2: How do I convert RPM to rev/s?
A: Divide RPM by 60 (e.g., 3000 RPM = 50 rev/s).

Q3: Does this account for propeller efficiency?
A: No, this calculates theoretical torque. Actual torque may differ due to efficiency losses.

Q4: What affects surface drive torque requirements?
A: Factors include propeller design, water conditions, boat hull shape, and operating speed.

Q5: How is this different for submerged propellers?
A: The basic torque formula is the same, but submerged props typically operate at different speeds and efficiencies.