Wind resistance calculation of large rotary mesh antenna and its influence on dynamic balance precision

大型回转网状天线风阻计算及其对动平衡影响研究

School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072, China

贺尔铭(1964-), 西北工业大学教授, 主要从事飞机结构动力学与振动控制研究。e-mail: heerming@nwpu.edu.cn

Received: 8 October 2020

Abstract

Due to the wind resistance which acts on the main reflector of large rotary mesh antenna, the correct balancing result of satellite antenna is difficult to be gotten in the ground dynamic balancing test. In order to solve this problem, the dynamic balance method of large rotary mesh antenna which is under the influence of wind resistance in both low pressure environment and standard atmospheric pressure environment on the ground is studied. Based on the theoretical analysis and the experimental data of two-dimensional flow around circular cylinder, a new method of the large rotary mesh antenna wind resistance calculation is proposed, according to the CFD analysis of the three dimensional flow field. Through the dynamic equivalent method, the distributed wind resistance acted on the main reflector of the mesh antenna in the rotating state is equivalent to the principal vector and principal moment of the action point in each quadrant, and then transformed into the eccentric mass on the distribution plane. It provides a feasible and innovative way to estimate the influence of wind resistance on the dynamic balance accuracy of large mesh antenna, so as to compensate the wind resistance effect. Combined with the ground dynamic balancing requirements of a certain type of satellite mesh antenna, the whole finite element model of the mesh antenna is established, the simulation of ground dynamic balancing test is carried out, and the influence of wind resistance on the ground dynamic balancing results of the antenna is analyzed in this study, which provides important data for compensating the influence of wind resistance and ensuring the on-orbit balancing accuracy of the antenna.

摘要

在地面动平衡配平试验中，由于大型回转网状天线主反射器受风阻的影响，卫星天线难以得到正确配平结果。为了解决这一问题，对大型回转网状天线在低压环境与地面标准大气压环境中风阻影响下的动平衡问题进行了研究。以理论分析及圆柱绕流二维试验数据为基础，提出了基于CFD三维流场分析的大型回转网状天线风阻计算方法，将回转状态下网状天线主反射器的分布风阻等效为作用点位于各象限的主矢、主矩，进而通过动力学等效法转化为配平面上的偏心质量，为估算风阻对大型网状天线动平衡精度的影响从而补偿风阻效应提供了一条可行的创新途径。结合某型星载网状天线地面动平衡需求，建立了网状天线的整体有限元模型，进行了地面动平衡配平试验仿真，分析了风阻对天线地面动平衡配平结果的影响，为补偿风阻影响、保证天线在轨配平精度提供了重要数据。