[目的]高分辨率激波捕捉格式对含激波流场的数值模拟具有重要意义,其不但可以降低网格的规模,而且能较好地分辨出流场中复杂的波系结构.[方法]通过在权函数公式中增加额外项的方式构造出WE-NO-N+3格式,并采用泰勒级数展开的方法对WENO-N3和WENO-N+3格式在极值点处的精度进行理论推导和精度数值测试.选用激波与熵波相互作用、双爆轰波碰撞、瑞利—泰勒不稳定性等问题验证改进格式WE-NO-N+3与WENO-JS3,WENO-Z3和WENO-N3格式的区别.最后,将改进格式WENO-N+3应用于内爆炸载荷的数值计算.[结果]研究表明,改进格式WENO-N+3相较其他格式耗散低,并且在相同的计算网格下能给出较高的冲击波峰值.[结论]该方法可用于内爆炸载荷的数值计算.%[Objectives] In this paper,an improved third-order WENO scheme named 'WENO-N+3' is constructed by adding a suitable term to the weights of the conventional WENO-N3 scheme.[Methods] The precision near the critical points of WENO-N3 and the WENO-N+3 schemes is derived using the Taylor expansion,and accuracy tests are also conducted. Shock-entropy wave interaction,interacting blast waves and Rayleigh-Taylor instability problems are selected in order to verify that the improved scheme WENO-N+3 has less dissipation than the conventional WENO-JS3,WENO-Z3 or WENO-N3 schemes,with high-resolution flow field structures. Finally,the proposed WENO-N+3 scheme is applied to simulations of explosion loads in a confined space.[Results] The simulation results indicate that the present scheme can provide a higher shockwave peak. [Conclusions] The findings of this paper can provide valuable references for research into the numerical calculation of internal explosion loads.
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