Jets, Props and Air Cushions: Propulsion Technology and Surface Effect Ships

1968 ◽  
Author(s):  
Alfred Skolnick ◽  
Z. G. Wachnik
Keyword(s):  
High Speed ◽  
Surface Effect ◽  
Broad Scope ◽  
The Status ◽  
Air Cushion

Following a brief review of the background and formulation of the jointly sponsored Navy/Commerce Department’s Surface Effect Ships (SES) Program, the paper offers a broad scope presentation on propulsion for SES, e.g., waterjets, supercavitating propellers, and lift fans. The problems associated with establishing the feasibility of successful designs and construction of such ships are considered, the status of development assessed and the efforts still remaining accordingly” defined. The paper deals primarily with the propulsion considerations of high speed ships using the air cushion principle in combination with vestigial rigid sidewall design.

Full-scale Performance of the SES Motion Control System

2015 ◽  
Author(s):  
Øyvind F. Auestad ◽  
J. William McFann ◽  
Jan T. Gravdahl
Keyword(s):  
Control System ◽  
Motion Control ◽  
High Speed ◽  
Wind Farm ◽  
Surface Effect ◽  
Vertical Plane ◽  
Full Scale ◽  
Offshore Wind ◽  
Motion Control System ◽  
Air Cushion

The pressurized air cushion on a Surface Effect Ship (SES) can lift up to 80% of total vessel mass. The SES Motion Control System (SES-MCS) controls the vent valves which again controls the air cushion pressure, assuming lift fan air flow is pressurizing the air cushion. By controlling the air cushion pressure one can significantly counteract vertical sea wave disturbances, ensure high passenger comfort and reduce sea-sickness. The case studied in this work is the Umoe Mandal Wave Craft prototype, ’Umoe Ventus’, which is a high-speed offshore wind-farm service vessel specially designed for control in the vertical plane. The SES-MCS can adjust the draft from 1m to 3.2m in less time than the wave period. The SES-MCS can reduce motions significantly in order to perform Operation and Maintenance (O&M) in high seas. The craft is the fastest wind-farm service vessel of its size with high comfort in all relevant sea states. The performance of the SES-MCS is demonstrated through full-scale sea trials.

Multihull and Surface-Effect Ship Configuration Design: A Framework for Powering Minimization

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Ronald W. Yeung ◽  
Hui Wan
Keyword(s):  
High Speed ◽  
Surface Effect ◽  
Early Stage ◽  
Base Line ◽  
Total Displacement ◽  
Surface Effect Ship ◽  
Linearized Theory ◽  
Air Cushion ◽  
New Formula ◽  
Analytical Expressions

The powering issue of a high-speed marine vehicle with multihulls and air-cushion support is addressed, since there is an often need to quickly evaluate the effects of several configuration parameters in the early stage of the design. For component hulls with given geometry, the parameters considered include the relative locations of individual hulls and the relative volumetric ratios. Within the realm of linearized theory, an interference-resistance expression for hull-to-hull interaction is first reviewed, and then a new formula for hull-and-pressure distribution interference is derived. Each of these analytical expressions is expressed in terms of the Fourier signatures or Kochin functions of the interacting component hulls, with the separation, stagger, and speed as explicit parameters. Based on this framework, an example is given for assessing the powering performance of a catamaran (dihull) as opposed to a tetrahull system. Also examined is the wave resistance of a surface-effect ship of varying cushion support in comparison with that of a base line catamaran, subject to the constraint of constant total displacement.

scholarly journals Influence of Spatially Varying Flow on the Dynamic Response of a Waterjet inside an SES

2014 ◽  
Vol 2014 ◽  
pp. 1-18 ◽  
Author(s):  
Michael R. Motley ◽  
Brant R. Savander ◽  
Yin L. Young
Keyword(s):  
High Speed ◽  
Surface Effect ◽  
Three Dimensional ◽  
System A ◽  
Air Cushion ◽  
Hydroelastic Response ◽  
Spatially Varying ◽  
Blade Loads ◽  
High Thrust ◽  
Flow Nonuniformity

Surface Effect Ships (SES) are a promising fuel-efficient ship technology that typically carry most of their weight on an air cushion. To accommodate its shallow draft and slender side hulls and to absorb the high thrust and power required for high-speed applications, waterjets are typically used as the primary propulsion system. A waterjet typically has a flush mounted inlet and operates under complex three-dimensional flow conditions that result in highly nonuniform flows. The objectives of this work are to quantify the flow nonuniformity and the influence of unsteady cavitation on the response of an SES-waterjet system and to investigate the effect of flow nonuniformity and cavitation on the dynamic hydroelastic response of the rotor and stator blades. The results showed that as the flow advances through the pump, the ingested boundary layer from the bottom of the side hulls becomes increasingly nonuniform, particularly between the rotor and stator. The flow nonuniformity was shown to result in hydrodynamic load fluctuations and high side forces on the rotor and stator blades. The unbalanced blade loads lead to the generation of net upward forces on the pump casing and shaft. Flow nonuniformity also leads to unsteady cavitation and unsteady blade stresses and deformations.

Curved surface effect on high-speed droplet impingement

2020 ◽  
Vol 909 ◽  
Author(s):  
Wangxia Wu ◽  
Qingquan Liu ◽  
Bing Wang
Keyword(s):  
High Speed ◽  
Surface Effect ◽  
Curved Surface ◽  
Droplet Impingement

Abstract

scholarly journals A Hybrid Temporal-Spatio Forecasting Approach for Passenger Flow Status in Chinese High-Speed Railway Transport Hub

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Zhengyu Xie ◽  
Limin Jia ◽  
Yong Qin ◽  
Li Wang
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Distribution Center ◽  
Railway Transport ◽  
High Speed Railway ◽  
Safety Hazard ◽  
Passenger Flow ◽  
Potential Safety ◽  
Correlation Degree ◽  
The Status

With the rapid development of high-speed railway in China, high-speed railway transport hub (HRTH) has become the high-density distribution center of passenger flow. In order to accurately detect potential safety hazard hidden in passenger flow, it is necessary to forecast the status of passenger flow. In this paper, we proposed a hybrid temporal-spatio forecasting approach to obtain the passenger flow status in HRTH. The approach combined temporal forecasting based on radial basis function neural network (RBF NN) and spatio forecasting based on spatial correlation degree. Computational experiments on actual passenger flow status from a specific bottleneck position and its correlation points in HRTH showed that the proposed approach is effective to forecast the passenger flow status with high precision.

Optimum Structural Design of High-Speed Surface Effect Ships Built of Composite Materials

2003 ◽  
Vol 40 (01) ◽  
pp. 42-48
Author(s):  
Chang Doo Jang ◽  
Ho Kyung Kim ◽  
Ha Cheol Song
Keyword(s):  
Composite Materials ◽  
Computer Program ◽  
Structural Design ◽  
High Speed ◽  
Surface Effect ◽  
Minimum Weight ◽  
Original Design ◽  
Optimum Structural Design ◽  
Surface Effect Ship ◽  
Speed Performance

A surface effect ship is known to be comparable to a high-speed ship. For the structural design of surface effect ships, advanced design methods are needed which can reflect the various loading conditions different from those of conventional ships. Also, minimum weight design is essential because hull weight significantly affects the lift, thrust powering and high-speed performance. This paper presents the procedure of optimum structural design and a computer program to minimize the hull weight of surface effect ships built of composite materials. By using the developed computer program, the optimum structural designs for three types of surface effect ships—built of sandwich plate only, stiffened single skin plate only, and both plates—are carried out and the efficiency of each type is investigated in terms of weight. The computer program, developed herein, successfully reduced the hull weight of surface effect ships by 15–30% compared with the original design. Numerical results of optimum structural designs are presented and discussed.

Practical Evaluation of Steady Flow Resulting from a Free-Surface Pressure Patch

2009 ◽  
Vol 53 (03) ◽  
pp. 137-150
Author(s):  
Francis Noblesse ◽  
Gérard Delhommeau ◽  
Chi Yang
Keyword(s):  
Free Surface ◽  
Surface Pressure ◽  
High Speed ◽  
Surface Effect ◽  
Practical Method ◽  
Analytical Approximation ◽  
Surface Boundary ◽  
Steady Flows ◽  
Local Flow ◽  
The Green Function

The linearized potential flow resulting from a distribution of pressure that advances at constant speed along a straight path at the free surface of calm water, of effectively infinite depth and lateral extent, is considered. A practical method for evaluating the free-surface elevation caused by the moving free-surface pressure patch—which can be used to model steady flows of air-cushion vehicles, high-speed planing boats, surface-effect ships, and some types of hybrid ships—is given. The key ingredient of this method is a highly simplified analytical approximation to the local-flow component in the expression for the Green function associated with the classic Michell-Kelvin linearized free-surface boundary condition.

Discussion Notes for a Review of Progress in Design of Large SES

1975 ◽  
Vol 12 (03) ◽  
pp. 254-259
Author(s):  
W. F. Perkins
Keyword(s):  
High Speed ◽  
Surface Effect ◽  
Commercial Application ◽  
Considerable Effort ◽  
Technical Design ◽  
Design Problems ◽  
Technical Problems ◽  
The Past ◽  
Design Solutions ◽  
Near Term

These notes are prepared to highlight some of the points in a review of progress in the development of oceangoing surface effect ships over the past ten years. In 1965, considerable interest was generated with respect to the application of large—more than 4000-tons—SES in ocean commerce. Since that time, considerable effort has been devoted to addressing the technical design problems associated with such ships. Emphasis has shifted in the near term to a military ship of about 2000-tons gross weight. Nonetheless, many of the design solutions to technical problems at the 2000-ton size are applicable to any large, high-speed SES. Thus, progress and success in the Navy programs can lead eventually to commercial application of SES.

An Analysis of Heave Added Mass and Damping of a Surface-Effect Ship

1981 ◽  
Vol 25 (01) ◽  
pp. 44-61
Author(s):  
C. H. Kim ◽  
S. Tsakonas
Keyword(s):  
Free Surface ◽  
High Speed ◽  
Surface Effect ◽  
Practical Method ◽  
Added Mass ◽  
Damping Coefficients ◽  
Calm Water ◽  
Surface Effect Ship ◽  
Long Time ◽  
Computational Procedures

The analysis presents a practical method for evaluating the added-mass and damping coefficients of a heaving surface-effect ship in uniform translation. The theoretical added-mass and damping coefficients and the heave response show fair agreement with the corresponding experimental values. Comparisons of the coupled aero-hydrodynamic and uncoupled analytical results with the experimental data prove that the uncoupled theory, dominant for a long time, that neglects the free-surface effects is an oversimplified procedure. The analysis also provides means of estimating the wave elevation of the free surface, the escape area at the stern and the volume which are induced by a heaving surface-effect ship in uniform translation in otherwise calm water. Computational procedures have been programmed in the FORTRAN IV language and adapted to the PDP-10 high-speed digital computer.

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