在相对旋转坐标系下采用Harten,Lax and van Leer contact(HLLC)格式离散对流项,自行开发了基于多块结构化网格的有限体积程序,实现了对叶轮机械内部流场的数值求解.分别对半开式径向叶轮、闭式后弯叶轮展开数值模拟,程序和商业软件计...在相对旋转坐标系下采用Harten,Lax and van Leer contact(HLLC)格式离散对流项,自行开发了基于多块结构化网格的有限体积程序,实现了对叶轮机械内部流场的数值求解.分别对半开式径向叶轮、闭式后弯叶轮展开数值模拟,程序和商业软件计算得到的不同叶高处表面压力数据,其相对差异不超过1%,验证了算法的正确性.针对湍流方程的扩散项,分别使用完全离散和略去交叉导数项离散,通过对湍流黏度等值线、气动轴向力和力矩的比较表明:在网格正交性较好的情况下,略去交叉导数项的离散对计算结果的影响小于1%,显著地减小湍流方程离散的计算量.展开更多
A hybrid numerical flux scheme is proposed by adapting the carbunclefree modified Harten-Lax-van Leer contact(HLLCM) scheme to smoothly revert to the Harten-Lax-van Leer contact(HLLC) scheme in regions of shear. This ...A hybrid numerical flux scheme is proposed by adapting the carbunclefree modified Harten-Lax-van Leer contact(HLLCM) scheme to smoothly revert to the Harten-Lax-van Leer contact(HLLC) scheme in regions of shear. This hybrid scheme, referred to as the HLLCT scheme, employs a novel, velocity-based shear sensor. In contrast to the non-local pressure-based shock sensors often used in carbuncle cures, the proposed shear sensor can be computed in a localized manner meaning that the HLLCT scheme can be easily introduced into existing codes without having to implement additional data structures. Through numerical experiments, it is shown that the HLLCT scheme is able to resolve shear layers accurately without succumbing to the shock instability.展开更多
文摘在相对旋转坐标系下采用Harten,Lax and van Leer contact(HLLC)格式离散对流项,自行开发了基于多块结构化网格的有限体积程序,实现了对叶轮机械内部流场的数值求解.分别对半开式径向叶轮、闭式后弯叶轮展开数值模拟,程序和商业软件计算得到的不同叶高处表面压力数据,其相对差异不超过1%,验证了算法的正确性.针对湍流方程的扩散项,分别使用完全离散和略去交叉导数项离散,通过对湍流黏度等值线、气动轴向力和力矩的比较表明:在网格正交性较好的情况下,略去交叉导数项的离散对计算结果的影响小于1%,显著地减小湍流方程离散的计算量.
基金the Singapore Ministry of Education AcRF Tier-2 Grant(No.MOE2014-T2-1-002)the Graduate Research Officer Scholarship from School of Mechanical and Aerospace Engineering,Nanyang Technological University,Singapore。
文摘A hybrid numerical flux scheme is proposed by adapting the carbunclefree modified Harten-Lax-van Leer contact(HLLCM) scheme to smoothly revert to the Harten-Lax-van Leer contact(HLLC) scheme in regions of shear. This hybrid scheme, referred to as the HLLCT scheme, employs a novel, velocity-based shear sensor. In contrast to the non-local pressure-based shock sensors often used in carbuncle cures, the proposed shear sensor can be computed in a localized manner meaning that the HLLCT scheme can be easily introduced into existing codes without having to implement additional data structures. Through numerical experiments, it is shown that the HLLCT scheme is able to resolve shear layers accurately without succumbing to the shock instability.
