Naval Architecture

Professors Neilson, Onas, Gallagher and Royce

The fundamental laws of buoyancy, stability, and strength are fully considered, as these have universal application to all kinds of ships and floating structures. The study of naval architecture is begun in the Freshman year in order to familiarize the student as early as possible with ship and shipbuilding terms, technical facets of ship analysis and design, shipyard arrangements and general methods of ship construction. Major subjects covered are hydrostatics, stability, ship structure, ship dynamics, resistance, and propulsion. Knowledge gained is subsequently applied in the design courses.

Owing to the wide variety of types and sizes of ships in service at the present time, it is inevitable that a certain amount of specialization is necessary for their design and construction. It is the aim of the courses to cover the fundamentals of naval architecture in the time available, so that the specialized study of any one of a number of particular types or classes of ships may be left to the individual who, after graduation, is especially concerned with them.

Freshman Year

          INTRODUCTION TO NAVAL ARCHITECTURE (NA I)

This course presents an overall introduction to the marine industry.  The terminology and the technologies of naval architecture are presented.  Graphic techniques, which form the basis for the naval architect’s understanding of ship form and lines drawing, are introduced.  The broad spectrum of ship types – from sailing yachts and tugs to mammoth tankers and aircraft carriers, from submarines to air cushion vehicles – are described.  Basic principles of hull structure are introduced, and from this a consideration of how to build ships is presented. The final part of the course is a direct preparation for the first winter work period. Two hours of lecture and two hours of lab per week in the first semester.

Sophomore Year

          SHIP STATICS (NA II)

This introductory course in hydrostatics of ships covers buoyancy, weights, metacenters, and stability at small and large angles of heel and trim. Stability after damage, and hydrostatic considerations in drydocking and grounding are treated. In the project part of the course, curves of form are calculated for a small vessel with much of the work done on a computer. Cross curves of stability are also calculated for the same hull form. Two hours of class and two hours of lab per week in the first semester.

Junior Year

          SHIP RESISTANCE AND PROPULSION (NA III)

The components of a ship's resistance and the effects of important hull parameters are discussed as well as the special problems of bulbous bows and hull appendages. Full-scale prediction of ship resistance by means of model tests, standard series, and regression analyses are examined and criticized. Wake fraction, thrust deduction, and propulsive coefficient are presented.  Limited discussion of screw propellers and operating points are provided. Two hours per week of lecture and a two hour laboratory every week in the first semester.

              SHIP STRUCTURES (NA IV)

The course provides a thorough introduction to modern ship structure analysis and design.  The loading experienced by ship structures is outlined. The engineering properties of shipbuilding materials and typical ship structure arrangements are described.  Methods for the analysis and design of the hull girder, beams, girders, unstiffened and stiffened plate panels are introduced.  Failure due to yielding and buckling are considered.  The assessment of fatigue performance of welded connections is also described.  Both analytical and finite element methods for analysis are presented and applied to typical ship structure.   Two hours of class and two hours of laboratory per week in the second semester.

Senior Year

           SHIP DYNAMICS (NA V)

In the first part of this course, the student applies knowledge of rigid-body dynamics, vibrations, and hydrodynamics to the study of seakeeping, which addresses the ship’s response behavior in ocean waves. In the second part, the ship’s maneuvering theory in calm water is developed. The seakeeping part starts with wave statistics. The wave environment is described mathematically first using the regular wave theory and then is expanded to a stochastic or probabilistic description of the seaway using wave spectrums and scatter diagrams. The ship equations of motion are developed for seakeeping, and calculation of the wave excitation force, added mass and radiation damping are introduced, based on strip theory and velocity potential formulation. The response of a ship to ocean waves is treated, first to a single wave train and then to a wave spectrum using linear superposition principles.

Calculations are compared to scale model test results. The ship response in head seas is investigated experimentally using a Series 60 model in the Robinson Model Basin and compared with published seakeeping test results. Computational Fluid Dynamics (CFD) using the Rankine-Panel Method is introduced as the numerical tool to investigate the ship response in time domain and analyzed in the frequency domain. The numerical test results are validated against the seakeeping lab test data and published test results. Seakeeping criteria are discussed, including critical vessel responses such as roll, deck wetness, slamming, and impact loads.

The equations of motion for maneuvering are developed in the second part of the course. Analytical and experimental methods of determining maneuvering coefficients are presented. Controls-fixed stability is discussed in detail and calculation of stability index is carried-out. The theory of ship turning is presented with calculation of turning parameters, emphasizing the limitation of linear theory. An introduction to rudder design follows and methods to evaluate the rudder performance characteristics are introduced. Three hours of class per week in the first semester.

          PROPULSOR DESIGN (NA VI)

This course examines the theory and design of the screw propeller for ship propulsion and exposes students to introductory computational fluid dynamics.Lifting line and lifting surface representations are used to design blade sections of a propeller for a candidate vessel. Cavitation criteria are considered.

Other propulsors are discussed for comparison. The course also considers computational fluid dynamics from a potential and fully viscous point of view. Free surface problems for simplified hull forms are considered. Three hours per week in the second semester.

          MARINE TRANSPORTATION (NA VII)

This course gives an overview of marine transportation systems, including tankers, breakbulk, drybulk,  and container lines from a business standpoint.  The fundamentals of maritime economics and financial management are presented, including a fleet analysis based on the ship design project begun in the Ship Design I course.  Case studies and a research paper are used as the primary learning tools.  Management techniques and linear programming are included.  Three hours of class per week in the second semester.