New flexible skirt design for amphibious ACV

• Published in: Transactions of the Krylov State Research Centre
• Main Authors: Vladislav V. Klitschko, Tatyana A. Dyakova, Oleg A. Zaitsev, Sergey O. Rozhdestvensky, Dmitry V. Fomichev
• Format: Article in Journal/Newspaper
• Language: English; Russian
• Published: Krylov State Research Centre 2020
• Subjects: amphibious air-cushion vessel; lifting system; air cushion; flexible skirt; hydrodynamic characteristics; test rig; towing tests; Naval architecture. Shipbuilding. Marine engineering; VM1-989; Arctic
• Online Access: https://doi.org/10.24937/2542-2324-2020-1-391-85-94; https://doaj.org/article/8e718aa7e37e4bdda744c029d89c93d7

Object and purpose of research. This paper discusses a new flexible skirt design for amphibious air-cushion vessel (AACV) featuring air cushion segmentation as per T-scheme, removable elements of increased height with broken generatrix and internal diaphragm. The main purpose of this work is to determine maintenance, stability and hydrodynamic characteristics of the AACV model with the new skirt design offering higher amphibious and seakeeping performance parameters. Materials and methods. The characteristics of the new skirt designed as per shape calculation methods for flexible ACV skirts were determined experimentally: stability characteristics were determined for the conditions of solid surface and water on a special test rig, hydrodynamic characteristics were obtained from the towing tests of AACV model in a high-speed seakeeping basin in still water and regular head waves performed with standard test equipment. Main results. The study yielded restoring moment-versus- roll angle curves of the model, as well as the data on model trim (with the new skirt) over a solid surface and over water. These data helped to determine relative metacentric heights (transverse and longitudinal). The effect of longitudinal alignment on transverse stability was examined. The study has also identified hydrodynamic parameters that determine propulsion and seakeeping performance of AACV in still water and in regular head waves. These findings have been analysed and compared with the model test data for the ACV with the air cushion split as per the “cross” approach and conventional (open-type) removable skirt elements. Conclusion. The study showed that suggested skirt design ensures necessary stability, propulsion and seakeeping performance of AACVs in still water and in waves, as well as high amphibious capacity due to increased height of removable elements. This new design can be recommended as a basis for further development of ACVs operating in difficult conditions of the Arctic shelf.