Based On Boundary Element Method Underwater Projectile Fluid Dynamics Numerical Analysis

Based on the theory of potential flow, the potential flow fields of whole wet, partially-cavitation and super-cavitation for underwater bullets are solved with panel method by distributing sources on the surface of body and cavity. The causation, the start condition of the cavity phenomenon and its influence on the resistance of underwater bullets are analyzed. For partially-cavitation and super-cavitation, the pressure recovery model is applied to simulate wake region, the influence of parameter variation on pressure distribution is analyzed. For a typical bullet, the relationship between cavitation number and cavity length and the relationship between the cavitation number and separating angle is studied. The cavity surface in the present method is determined iteratively.the calculation result indicate that this method converges quickly. The pressure distribution was calculated numerically at cavitation and super cavitation condition; the results are compatible well with the experimental data. The drag coefficient of underwater bullets at partially cavitation and super cavitation is acquired under the condition of zero angles of attack. The results provide certain reference for shape design and trajectory design for underwater bullets.