What Is the Admiralty Coefficient Ship Propulsion Power Calculator?
The Admiralty coefficient is an empirical formula widely used in early ship design to estimate required engine power.
How Does the Admiralty Coefficient Ship Propulsion Power Calculator Work?
Models frictional drag proportional to wetted area (Delta^(2/3)) and power proportional to speed cubed (V^3).
Admiralty Coefficient Ship Propulsion Power Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
P = rac{Delta^{2/3} V^3}{C_{ ext{adm}}} quad [ ext{kW}], quad P_{ ext{hp}} = P imes 1.341
Admiralty formula for preliminary propulsion power sizing in displacement vessels.
How to Use the Admiralty Coefficient Ship Propulsion Power Calculator
- Input vessel displacement in metric tonnes, desired cruising speed in knots, and Admiralty coefficient.
Step-by-Step Example Calculation
Handysize Bulk Carrier Powering
Input Values:
displacementTonnes:30000
serviceSpeedKnots:17
admiraltyCoefficient:520
Worked Steps: Requires 9,114 kW (12,222 HP) of continuous shaft propulsion power.
Understanding Your Result
Provides required continuous rated shaft engine power in both kilowatts (kW) and brake horsepower (HP).
Factors That Affect the Result
- Higher speeds cause wave resistance to grow faster than V^3, reducing the effective Admiralty coefficient.
When Should You Use This Calculator?
- Preliminary main engine selection, ship concept trade-off studies, and fleet speed-fuel consumption benchmarking.
Assumptions & Limitations
- Valid for displacement vessels operating at moderate Froude numbers (Fn < 0.35).
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard preliminary naval architecture design estimation method.