激光非均匀加热效应严重影响着激光能量的远距离传输。对于矩形平顶光束，在有轴向流存在的情况下，采用光束旋转的方式，借助商用的计算流体力学（CFD）软件Fluent，对激光在内通道中传输的气体热效应问题进行了仿真分析。仿真结果表明，激光束在横截面内的旋转，并不改变光场与气体耦合热效应到达稳态的时间。但是光束旋转效应使得光强非均匀分布带来的二阶像散项基本消失，光程差中只包含沿光轴方向对称的离焦项和球差项。而离焦项是便于校正的，因此光束旋转能够改善激光在内通道中的传输特性。

Heterogeneous heating of the laser beam is one of the most important effects on the beam propagating through the atmosphere. For the intensity distribution of the flat-topped rectangular beam, the rotary laser beam is adopted to weaken the thermal effects induced by the heterogeneous beam intensity distribution. Based on the computational fluid dynamics(CFD) software of Fluent, thermal effects of the beam in the line pipe with axial pipe flow are modeled. The results indicate that the second order astigmatism which is one of the greater components of optical path difference(OPD) induced by the heterogeneous beam intensity distribution is almost vanished because of the rotary laser beam, while the defocus and the spherical aberration which are the other greater components of the OPD are still exist. The effect of rotary laser beam does not affect the time of the thermal effects reaching the steady state. So the rotary beam effect can improve the beam propagating property.