Lower order tensors in non-K\"ahler geometry and non-K\"ahler geometric flow

In recent years, Streets and Tian introduced a series of curvature flows to study non-K"{a}hler geometry. In this paper, we study how to construct second order curvature flows in a uniform way, under some natural assumptions which holds in Streets and Tian’s works. As a result, by classifying the lower order tensors, we classify the second order curvature flows in almost Hermitian, almost K"{a}hler and Hermitian geometries in certain sense.