On calculating the radiated ballistic phonon power in phononic crystal membranes
On calculating the radiated ballistic phonon power in phononic crystal membranes
复制标题
声子晶体膜中辐射弹道声子功率的计算
DOI：
10.1063/1.4772517
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
I. Maasilta
中科院分区：
文献类型：
--
作者：
T. Puurtinen;I. Maasilta
声子晶体是周期性调制的结构，其中由于干涉或布拉格反射，声子谱（色散关系）被强烈地改变。在所有实际情况中，必须使用例如有限差分法或有限元法对所得的色散关系进行数值计算。我们表明，如果在计算声子群速度时直接使用有限元建模的结果，那么在计算热导率或辐射功率时很容易产生相当大的数值误差。我们在此引入一种本征频率面的排序算法来减少这种由k空间点离散化引起的误差。
Phononic crystals are periodically modified structures, where the phonon spectra (dispersion relations) are strongly modified due to interference, or Bragg reflections. In all practical cases, the resulting dispersion relations have to be calculated numerically, using for example the finite difference or the finite element method. We show that if one uses the results of finite element modeling directly in the calculation of phonon group velocities, a sizeable numerical error in the calculation of thermal conductance or radiated power can easily follow. We introduce here a sorting algorithm for the eigenfrequency surfaces to reduce this error, which arises from the discretization of the k-space points.