Naval Architecture & Ocean Engineering

# EN353: Resistance and Propulsion

## Catalog Description

### EN353: Resistance and Propulsion (3-2-4)

Topics include dimensional analysis, similitude, wave and viscous resistance of ships, ship-model testing techniques, full-scale performance prediction, momentum theory of propulsion devices, and propeller vibrations and design.

### Textbook

• Principles of Naval Architecture: Volume II (Lewis, 1988)
• Various supplemental materials, including a propeller selection notebook, ship series design data sheets, excerpts from The Speed and Power of Ships (Taylor, 1911), and laboratory handouts.

### Goals

1. Understand the parameters (water depth/viscosity and operational factors) that affect resistance. Understand and be able to describe the various components of resistance and their impact on overall ship resistance.
2. Understand the principles of estimating resistance based on series data and based on experimental testing. Be able to work through hand calculations to estimate horsepower using series data.
3. Understand propeller geometry, characteristics, and operation. Be able to carry out a propeller selection based on series data. Understand principles of torque and thrust with respect to propeller operation. Be able to understand and use an open-water propeller diagram.
4. Understand the phenomenon of cavitation, its detrimental effects, and causes of inception.  Be able to calculate cavitation number and quantify blade cavitation.
5. Understand propulsion train components and characteristics. Be able to carry out horsepower/resistance/efficiency calculations in a variety of scenarios.
6. Understand the operation of a foil, generation of lift, causes of stall, and the concept of circulation.

### Prerequisites

• EN247, Principles of Naval Architecture and Marine Engineering, OR
• EN245, Principles of Ocean Engineering Systems, AND
• EM316, Thermo-Fluid Sciences I, OR
• EM324, Fluid Dynamics

### Class Topics

1. Dimensional Analysis
2. Components of Ship Resistance and EHP Testing
3. Viscous Resistance
4. Wavemaking Resistance
5. Air Resistance
6. Submarine Resistance
7. Appendage Resistance
8. Shallow Water Effects
9. Design Using Series Data
10. Propulsion Train Components and Efficiency
11. Propeller Selection and Matching
12. Cavitation
13. Foil Theory
14. Planing Hulls

### Computer Usage

The students are required to make extensive use of the capabilities of their spreadsheet program for this course. The students are required to develop spreadsheets for performing resistance and propulsion calculations. The students are also encouraged to use their spreadsheet program in the design of a propeller so that they can perform some optimization of their design.

### Laboratory Projects

1. Model Ballasting
2. Resistance of a Flat Plate
3. Boundary Layer Measurement
4. Model Scaling Effects on Resistance Prediction
5. Planing Hull Testing
6. Submarine Testing
7. Propeller Measurement
8. Open-Water Propeller Efficiency
9. SHP Model Testing
10. Cavitation Effects on Propellers