ABSTRACT
In the early time of entering water, the head shape of structure will determine the load characteristics directly, so the structure can be simplified as slender body with the same aspect ratio and mass distribution. Tangent ogive structure has features of stable hydro-ballistic and small sailing resistance, and it is usually used as underwater weapon. A typical ogive structure shape is shown in Figure 1, which is described by apex angle α and scanning angle β. R1 is scanning radius, R0 is projectile radius, and β is the central angle corresponding to arc AB [5]. For tangent ogive structure, according
1 INTRODUCTION
Many processes, such as seaplane’s landing, spacecraft’s recycling and torpedo’s entry into the water, will face the problem of water-entry. Especially, spacecraft and torpedoes have a relatively large speed, which can produce huge impact load during the early time of entering water. The impact may cause structural damages, device failure, trajectory out of control and other issues. Analysis of the load distribution and flow field changes on the water-entry processes is the basis of shape optimization design and security assessment, also the core content of hydro-ballistic research.
