Flowfield around a blunt body at transonic speed is simulated numerically.It indicates that plentiful flowfield structures behind the blunt body determine base pressure distribution.Numerical simulation of free pitch oscillation shows that limited cycle oscillation is observed as a result of dynamic instability in transonic regime.During a free pitch oscillation,front part blunt body conducts work to the flow field which releases blunt body energy and inhibits swing.The rear part of the blunt body gains energy from the flow field which increases the blunt body energy and the motion is considered unstable.As energy of the front blunt body and the rear body is equal,the capsule falls into a limited cycle oscillation.

To design a high-order accurate shock capturing method for hyperbolic conservation laws,we introduce a new power limiter to obtain a second-order power NND scheme and a third order power WNND scheme based on modification of NND scheme and WNND scheme.By applying the limiter to first-order differences of the candidate stencils,the power NND scheme and the power WNND scheme reduce the smearing near discontinuities.The power NND scheme and the power WNND scheme show less dissipation and less spurious oscillations,and catch the discontinuities more accurately than NND scheme and WNND scheme.The results of power NND scheme are similar to those of WNND scheme,and even better in some examples.The simulation of forced oscillation of the NACA0012 airfoil by power WNND scheme is in good agreement with experiments.