Craft Air Cushion Research Articles

Hydrodynamics of new high-speed surface systems

Until recently, high-speed surface vessels consisted mainly of hydrogliders, airfoil boats, hydrofoil and air-cushion craft. Their hydrodynamic characteristics are well understood and the vessels involved have high speeds and excellent sailing qualities. In recent years, however, there has been some expansion of this group of vessels by means of high-speed surface objects on wheels (baggies) and tracks (snowmobiles), in some cases at speeds far exceeding those of hydrofoil and air-cushion craft. Information on the hydrodynamic characteristics of these vessels is not available in the literature. This prompts us to study their hydrodynamic parameters and to consider the practical use of these vessels. The report describes conditions for water rolling of wheeled and tracked systems with grousers, simulates this phenomenon, derives the dependence of draft and bearing capacity of wheeled systems on the Froude number, and presents the dependence of tracked traction on the dimensionless parameter equal to the ratio of absolute speeds of the lower part of a track and the above-water part of a model.

Maximum lift-drag ratio of air cushion craft

ABSTRACTThis paper develops a method to determine the lift-drag ratio of air cushion craft and specifically the maximum value of the lift-drag ratio, its associated design speed, and related performance and economic measures. The method works from well-established equations for drag and power for air cushion craft. Such values are required to determine the performance and economic efficiency of the craft in many modes of operation. The method covers both amphibious and non-amphibious craft of the types used in both military and commercial operation. A basis is developed for an optimisation procedure to design future craft for maximum efficiency.

Lift-curve slope for finite-aspect-ratio wings

References vis, D. R., Bartholomew. R. J., and Jones, J. C. ., Response of Cushion Vehicles to Random Seaways and the Inherent Distortion in Scale Models, Journal of Hydronautics, Vol. 8, July 1974, pp. 83-94. Richardson, J. R., A Scaling Technique for Hovercraft Models, Hovercraft Unit, National Physical Laboratory, G. B. Rept. 13, July 1970. Sullivan, P. A., Hinchey, M. J., Graham, T. A., Byrne, J. E., and Walsh, C., Investigations of the Dynamics of Large Cushions, Transportation Development Center, Transport Canada, Montreal, Quebec, TP-7560E, Aug. 1986. Mantle, P., Air Cushion Craft Development, U.S. Navy, David W. Taylor Naval Ship Research and Development Center, Bethesda, MD, Rept. DTNSRDC-80/012, Jan. 1980, pp. 61-65. Collar, A. R., The Expanding Domain of Aeroelasticity, Journal of the Royal Society, Vol. 50, Aug. 1946, pp. 616-636. Penaranda, F. E. and Freda, M. S., Aeronautical Facilities Catalogue, Vol. 1, Wind Tunnels, NASA RP-1132, Washington, D.C., Jan. 1985.

AIR CUSHION CRAFT

Naval Engineers JournalVolume 97, Issue 2 p. 259-316 AIR CUSHION CRAFT David Lavis, David Lavis David Lavis was educated in Exmouth and Exeter, Devon, England. He began his professional career in air cushion vehicles with Saunders-Roe on the Isle of Wight in 1959. Initially, as a student apprentice, Mr. Lavis worked on many aspects of air cushion vehicle research, design, and construction. In 1966, he received a master of science degree from Cranfield Institute of Technology. A year later he joined Bell Aerosystems, Buffalo, New York and was engaged in the early design work for the SES-100B and the AALC Jeff(B). Mr. Lavis then joined the Aerojet General Corporation (AGC) in Sacramento and in 1972, he was appointed manager of technology for the AGC, SES Division, who were at that time testing the SES-100A and conducting the early design work for the 2KSES and AALC Jeff(A). Mr. Lavis has continued to support the U.S. Navy advanced ship programs. In 1977, together with Mr. E.G.U. Band, he formed Band, Lavis & Associates, Inc. of Severna Park, Maryland, a company specializing in advanced marine technology.Search for more papers by this author David Lavis, David Lavis David Lavis was educated in Exmouth and Exeter, Devon, England. He began his professional career in air cushion vehicles with Saunders-Roe on the Isle of Wight in 1959. Initially, as a student apprentice, Mr. Lavis worked on many aspects of air cushion vehicle research, design, and construction. In 1966, he received a master of science degree from Cranfield Institute of Technology. A year later he joined Bell Aerosystems, Buffalo, New York and was engaged in the early design work for the SES-100B and the AALC Jeff(B). Mr. Lavis then joined the Aerojet General Corporation (AGC) in Sacramento and in 1972, he was appointed manager of technology for the AGC, SES Division, who were at that time testing the SES-100A and conducting the early design work for the 2KSES and AALC Jeff(A). Mr. Lavis has continued to support the U.S. Navy advanced ship programs. In 1977, together with Mr. E.G.U. Band, he formed Band, Lavis & Associates, Inc. of Severna Park, Maryland, a company specializing in advanced marine technology.Search for more papers by this author First published: February 1985 https://doi.org/10.1111/j.1559-3584.1985.tb03401.xCitations: 2 AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume97, Issue2February 1985Pages 259-316 RelatedInformation

A Study on Vibration of the Pneumatic Seal Structure of the Air Cushion Craft

A fundamental study on vibration characteristics of the air cushion craft was performed taking dynamic behavior of the pneumatic seal structure into consideration.A linearized mathematical model of the air cushion craft dynamics was derived. The effect of each parameter on the dynamic stability was obtained analytically and experimentally from the view point of negative resistance excitation system.The conclusions are as follows : 1) The dynamic stability of pneumatic seal structural vibration depends on the air transmission line characteristics and the seal configuration. The effects of these parameters on the stability criteria of the system are numerically examined.2) In the model test, the self excited vibration caused by the instability of the pneumatic seal system was observed in some range of the inlet area of fan and feedhole area in the air chamber.3) The calculated fundamental natural frequency for air cushion craft model agreed very well with model test results. The stable region varied in accordance with feedhole area in the model test, and a similar tendencies were also observed in the numerical analysis.A further study is necessary to discuss the difference between model test results and numerical analysis results.

BETWEEN THE BOOKENDS

Book reviewed in this article:BATTLESHIPS: United States Battleships in World War II, by Robert O. Dublin, Jr., William H. Garzke, Jr. & Robert F. SumrallShips and Naval Architecture, by R. Munro—SmithA Technical Summary of Air Cushion Craft Development, by Peter J. Mantle

Air cushion craft propulsion.

Air cushion craft propulsion.

III—The Rhyl–Hoylake Experiment

This paper has been written with the SRN-2 and VA-3 type of craft in mind; they are basically over water craft but with a capability of operating over land for the purpose of embarking or disembarking passengers and freight or of crossing mud flats or sandbanks. Immersed sidewall craft have not been considered since their problems are similar to those of high-speed launches. Overland air-cushion vehicles will, as Mr. Lamb has pointed out, most likely operate over prepared routes and therefore navigation should not present any problems.The main advantage offered by air-cushion craft is speed. The second advantage is its amphibious capability. Because of this an air-cushion craft can operate routes that are out of the question for any other kind of vehicle except perhaps a helicopter. An example of such a route is the proposed Rhyl–Hoylake ferry, which at low water is almost an overland route.