我觉得应该是比例系数。
原因：
1. 没有单位
2. 帮助文件中说：To define an orthotropic thermal conductivity, select Orthotropic from the Conductivity type drop-down list and specify the thermal Conductivity. To define the degree to which the orthotropic conductivity varies in each coordinate direction, specify a scaling factor for the conductivity in each of the X, Y, and Z coordinate directions.