Thesis (Nav. E. and S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2005. / Includes bibliographical references (p. 66-67). / In the naval architecture terminology, the term ACV (Air Cushion Vehicle) refers to this category of vehicles, in which a significant portion of the weight (or all the weight) is supported by forces arising from air pressures developed around the craft, as a result of which they hover in close proximity to the sea. Major types are hovercrafts and SES (Surface Effect Ships). A well-designed Air Cushion Vehicle (ACV) is superior to a conventional ship, because it has less drag and requires less horsepower to operate at the same speed. An ACV is much more fuel-efficient than a ship with similar capacity or size. Rising fuel prices and shortages will make ACVs a desirable form of transportation in the future. In order to cover this future trend in marine transportation, a MathCAD model for the estimation of the main characteristics of Air Cushion Vehicles in the preliminary design stage is being developed. This model is based on a statistical analysis of the various parameters of existing crafts. For this reason, a statistical database has been created using publicly available information. A regression analysis has been performed using the data collected and the trend lines for every case have been derived. / (cont.) For the validation of the code, LCAC (Landing Craft Air Cushion) is used as the reference vehicle. The values of LCAC design parameters that are known, are input in the code and crosschecked with the outputs. Iterative procedures have been applied to the code in order to correct the trend lines according to the reference model. The development of this MathCAD model is directly related to the lack of software dealing with the design of ACVs in the market. Conventional ship design tools are widespread and used even by students. On the other hand, ACV design programs are possessed by the companies that design this kind of crafts and are not widely available. In the following pages, together with the analysis of the model developed, the associated theory is presented so that the reader has a complete image of what an ACV is and how it works. Hence, this thesis is not a manual of a program, but a combination of theory and application intended to help the reader-user understand the design process of ACVs. / by Georgios Gougoulidis. / Nav.E.and S.M.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1992. / Includes bibliographical references (leaves 142-159). / by Christian Bliek. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1997. / Includes bibliographical references (p. 125-133). / by Scott Donald Black. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1999. / Includes bibliographical references (p. 111-113). / by Patricia A. Manning. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1999. / Includes bibliographical references (leaves 121-126) and index. / This thesis develops a method to analyze the maneuvering forces on surfaced and underwater vehicles with complex propulsors. The analysis method is developed for general propellers yet has unique applicability to model highly contracting stern flows associated with integrated propulsors. Integrated propulsors exhibit strong coupling of the various blade-rows and duct, if present, to the vehicle stern. The method developed herein provides a robust means to analyze propulsor-induced maneuvering forces including those arising from wake-adapted, multi-stage, ducted propulsors. The heart of the maneuvering force prediction is a three-dimensional, unsteady lifting-surface method developed as the first part of this thesis. The new method is designated PUF-14 for Propeller Unsteady Forces. The lifting-surface method uses many advanced techniques. One significant advance is the use of a wake-adapted lattice to model the flow through the propulsor. In related research, a 2-D Kutta condition has been augmented using Lagrangian interpolation to dramatically reduce the required computational time to model a 2-D gust. The second thrust of this thesis couples the unsteady lifting-surface method with a three-dimensional, time-average Reynolds-Averaged Na vier-Stokes flow solver. Rotating a propeller through a spatially-varying flow field causes temporally-varying forces on the propeller. From the converged-coupled solution, the maneuvering and blade rate forces can be estimated. This thesis explores the relationship of time-varying and time-average forces in the flow solver and potential-flow domains. Similarly, it explores the relationship of the effective inflow in the two domains. Finally, this thesis details the synergistic means to correctly couple the potential-flow method to a viscous solver. Verification and validation of the method have been done on a variety of geometries and vehicles. Preliminary results show good correlation with experiment. The results strongly suggest this maneuvering force prediction method has great potential for the modern propulsor designer. / by Christopher L. Warren. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1998. / Includes bibliographical references (p. 143-150) and index. / by Mark W. Thomas. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1994. / Includes bibliographical references. / by Qing Zhou. / Ph.D.

Massachusetts Institute of Technology. Dept. of Ocean Engineering. Thesis. 1971. Sc.D. / MICROFICHE COPY ALSO AVAILABLE IN BARKER ENGINEERING LIBRARY. / Vita. / Bibliography: leaves 572-593. / Sc.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1996. / Includes bibliographical references (leaves 137-141). / by Rama Rao V.N. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1994. / Includes bibliographical references (leaves 208-222). / by Gökhan Gk̈tuğ. / Ph.D.