山区地形对大口径高精度射电望远镜台址风场调控影响的数值模拟研究

Research on Wind Flow Regulation Influenced by the Mountain Terrain at Large Aperture and High Precision Radio Telescope Site Based on Numerical Simulation

优化台址风环境对提高大口径、高精度射电望远镜在中高频段的有效观测时长具有重要意义。通过风障调控风场可以有效减小风荷载对望远镜的影响。风障的布局设计除了与风障高度、孔隙率等参量有关外,还要综合考虑台址地形对挡风效率的影响。以奇台射电望远镜(QiTai radio Telescope,QTT)台址为研究对象,开展不同地形对风场调控影响的数值模拟研究。仿真结果表明,无风障时望远镜区的风速大小主要与上下游边界地形的最高海拔有关;布设风障时,若望远镜区域为水平地形,风障遮蔽区降低风速的大小与上游入流风攻角以及下游地形的海拔高度有关;台址实际斜坡地形增加了流场的复杂程度,在进行风障风场仿真时,上游边界要尽量延伸到相对较高山体的外围。不同边界地形的仿真结果表明,望远镜区风速折减效率差值最大达到6%。该研究可以为望远镜台址风场调控仿真中的地形建模提供可靠的参考。

Optimizing the wind environment at the site is important to improve the effective observation time of large-aperture and high-precision radio telescopes in the middle and high frequency bands.Through wind barrier regulating wind flow that can effectively reduce the impact of wind load on the telescope,the layout design of wind barriers is not only related to the height,porosity and other parameters of wind barriers,but also consider the impact of the terrain on wind shield.However,there are few researches on this area.Taking the QiTai radio Telescope(QTT)site as the research object,the influence of different terrains on regulating wind flow is carried out based on numerical simulation.The simulation result shows that the wind speed at the telescope location without wind barriers is mainly related to the highest elevation of the upstream and downstream boundary terrain.Under the condition with wind barriers,if the telescope is located in horizontal terrain,the magnitude of reducing wind speed in the shelter area is related to the wind attack angle of the upstream incoming wind and the elevation of the downstream terrain.The actual slope terrain of the site increases the complexity of the wind flow,and when doing wind flow simulation for wind barriers,the upstream boundary should be extended to the outside of the relatively high mountain as far as possible.The simulation result of different boundary terrains show that the difference of reducing wind speed coefficient at telescope position reaches a maximum of 6%.This study can provide a reliable reference for terrain modeling of regulating wind flow simulation.