用Navier-Stokes方程数值模拟弹丸绕流流场

Numerical Simulations of Projectile Flow with Navier—Stokes Equations

随着计算流体力学和计算机技术的发展,流场数值预测技术已被应用于弹丸绕流流场,特别是底部流场的数值模拟研究.目前,在这类研究中,广泛采用薄层方程组和近似因子分解技术.由于薄层假设不适用于底部流动;因而给底部流场的计算造成较大误差,而近似因子分解误差的引入亦在很大程序上限制了大时间步长求解,降低了计算效率.针对这种情况,本文从全Navier—Stokes方程组出发,采用八十年代中期发展起来的Mac Cormack显隐格式,计算了一种弹形的绕流流场,并对计算结果进行了分析和讨论.

With the development of computational fluid dynamics and computer technology,numerical Navier—Stokes simulations have been applied to investigations of flowfield overprojectile surface,especially base region.In recent years a considerable research effort hasbeen focused on the solutions of thin—layer Navier—Stokes equations with the Beam—Warm-ing fully implicit.approximately factored finite difference scheme.The thin—layer approx-imation,however,is not suitable to the base flow,and computations with large time step arerestricted due to the approximate factorization.In view of this situation,the fully Navier—Stokes equations was solved using the 1985 MacCormack explicit—implicit finite differencealgorithm in the present paper,and numerical results were discussed.