The Research Of Supercavitating Shape And Drag And Optimizing Cavitator Shape

The cavitation phenomenon has already experienced several generations' understanding and reaserching from it is discovered up to now.Until 1994 Russia manufactured the first supercavitating torpedo which speed can reach at 200kn successfully, this speed breaks the thinking of tradition that it only can up to 140kn underwater,exciting the fever of study the supercavitation in many countries.Uder such background,in this article studies in supercavitation and supercavitating drag; optimizes supercavitating torpedo shape and cavitator shape. The subject comes from the foundation research of important project. The main contributions are as follows:1. Refer to bore cavitation and developing cavitation ,as well as cavity profile exrired in the water tunnel,and analyzed the phenomenon of cavitation and cavity profile,four stages of cavitations are developed,which is easy for research and expression the concept of steady supercavity;2. From the potential flow theory, the approximation function on cavitator and cavitation number with the cavity profile is deduced and created according to the slender body theory. And analyse the main factor of influence on cavitation;3. Research on drag and reduction drag of supercavitation .Refer to result of experiment of foreigner scholar, summarized formula in laminar and turbulent flow of aixsymmetry slender body.Refer to foreigner scholars'result of research, discuss the tools of avoiding flow pattern separation;4. Using of steady cavitation princiole which foreigner scholars put forward to establish supercavitating model ,the make use of criterion formula to establish object function and optimize this fuction,and find the optimum shape of supercavitating torpedo;5. To analyse supercavitating flow, make use of free boundary value theory, transform this problem to equivalent optimized problem, then regard optimizing supercavitating flow as part optimizing and regard optimizing cavitator shape as main object of optimizing then optimize this double optimizing problem and find the optimum shape of cavitator.But because of variouse reasons, the information of cavitation research and supercavitating torpedo design is very limited in public literature. Especially in the domestic, this research is started, still be placed in to the comprehension and summaries of the foreigner literature.Therefore, this article on studies to the cavitation and supercavitating torpedo shape is very important for the oher research and the design of supercavitating torpedo shape.