The jacked rod is new kind of kinetic projectile with high length-to-diameter ratio that deal with the armor target in the battlefield. The Jacketed rod consists of a central high-density core surrounded by a low density jacket. Compared with ordinary long-rod penetrator, the aerodynamic characteristics of the jacketed rod are different because of the jacket structure. In this paper, the external flow field of the jacketed rod is simulated using the computational fluid dynamics software FLUENT. The aerodynamic shape of the jacket is changed to observe the flow field around the rod and obtain the corresponding aerodynamic parameters. The main consideration of the aerodynamic shape includes the shape of the front and rear ends, the recessed or convex groove of the ring groove and the disturbed flow between the annular teeth. By analyzing the variation of aerodynamic parameters, the influence law of jacket shape on aerodynamic characteristics are obtained. 1. The cone angle at the front end of the jacket greatly reduces the air resistance of the jacketed rod. 2. Though boat-tail angle has the optimal value to minimize air resistance, the effect of it on air resistance is negligible when the jacketed rod is during hypervelocity flight. 3. The jacket with the convex teeth causes an air resistance of 30 to 35% larger than that of the jacket with concave teeth. 4. The resistance caused by the disturbed flow between the annular teeth of the jacket accounts for approximately 25-27% of the total air resistance. Finally, the optimization opinion of the structure of the jacketed rod is proposed from the aerodynamic layout.
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