Research On Technology Of Amphibious Gun With Retractable Hydrofoils

Amphibious gun,the military equipment for land warfare,over-water navigation and shooting combat,is the main firepower assault force and an important part of amphibious combat,playing an irreplaceable role of the army in amphibious operations.The improvement of the rapidity of over-water navigation has also become the main factor of influencing amphibious gun battlefield viability and one of the key indicators to measure its performance.Hence,it is significant to investigate technology of speed increasing and resistance reduction and improve the speed and stability of amphibious gun during over-water navigation.In this paper,based on the structural characteristics of amphibious gun,the technical approach that retractable hydrofoils were installed to increase the speed by resistance reduction and increase the stability of amphibious gun was proposed,and scheme of the retractable hydrofoils was designed.And the characteristics of the hydrofoil and the effect of the resistance reduction of amphibious gun were simulated by the fluid analysis software.The main content of this paper are as follows:(1)Combined with the structural characteristics of the traditional amphibious gun,the scheme was proposed to install retractable hydrofoils,matching with the structure of amphibious gun on the body of amphibious gun,and meanwhile hydrofoils were designed.The whole and partial three-dimensional modeling of the amphibious gun with retractable hydrofoils was established by Solid works.The resistance of amphibious guns before and after the installation of retractable hydrofoils was analyzed respectively.The results show that rapidity of amphibious gun during over-water navigation is less affected by retractable hydrofoils installation.(2)The body was lifted out of water as much as possible by hydrodynamic lift generated from fluid movement of hydrofoils,so that fluid resistance rapidly decreased to increase speed.The flow field of amphibious gun and hydrofoil was meshed by Workbench,and then fluent fluid simulation was carried out.The variation of draft,pressure and velocity distribution,lift and resistance of amphibious gun before and after the installation of hydrofoils were analyzed under different speeds during over-water navigation.The results show that with the increase of the velocity,the lift of the amphibious gun increases rapidly,the draft and resistance decreases gradually,and the lift-drag ratio increases,which fully achieves the purpose of increasing speed by resistance reduction.(3)In order to ensure the on-land navigation and combat of amphibious gun not to be influenced by the installation of the hydrofoils,a practical retractable hydrofoil device and corresponding driving system were designed in this paper,so amphibious gun can be completely stowed during the on-land navigation and shooting,and can be fully lowered and extended during over-water navigation and combat to increase speed and improve stability.Three-dimensional entity models of retractable device and relating specimens were established,and meantime dynamic simulation was carried out with ADAMS software.