低温风洞防护结构设计与强度校核

Design and Strength Check on Protective Structure in Cryogenic Wind Tunnel

防护结构作为低温风洞内绝热系统的一个重要的子系统,具有隔绝绝热单元与低温介质、降低冷量损耗、形成气流通道的作用。然而,其在风洞运行过程中不断承受着风洞运行的低温载荷和交变压力载荷,为此,重点开展防护结构设计和强度校核研究。首先,对防护结构进行总体设计,明确各部件尺寸和材料;然后,建立防护结构三维有限元模型,根据低温风洞运行的最恶劣工况对防护结构进行强度分析;最后,对防护结构进行低温环境下的交变压力冲击试验。结果表明,设计的防护结构满足风洞运行工况下的强度要求,但在支撑件附近存在冷量损耗。这对中国自主开展大型低温风洞的设计建设具有重要的借鉴意义。

Protective structure,acted as an important subsystem of internal insulation system in cryogenic wind tunnel,is in possession of such functions as isolating insulation unit from cryogenic media,reducing cold energy loss and forming the airflow channel.However,the protective structure is continuously subjected to the temperature load and alternating pressure load during the operation of wind tunnel.Thus,the design and strength check on protective structure were intensively investigated.Firstly,the protective structure was designed and the corresponding sizes and materials were determined.Then,according to the worst working condition of cryogenic wind tunnel,three dimensional finite element models of protective structure was built and the strength check was conducted.Finally,the alternating pressure impact test under cryogenic environment was carried out on protective structure.The obtained results show that the designed protective structure is conformed to the strength requirement of cryogenic wind tunnel in service,but the cold energy loss occurs nearby the support component,which can pay the way for building the large cryogenic wind tunnel of our country in the future.