飞机风洞试验模型的设计和加工是风洞试验的重要环节,对飞机研制的周期和成本具有重要的影响.为提高飞机研制的效率,基于3D打印技术提出了实用化飞机风洞模型的设计和制造方法.采用3D打印加工树脂气动外壳和机加工金属强化骨架的复合结构方案,设计并测试了某型号飞机的低速全机测力模型.提出了变角片和旋转轴-定位销两种舵面偏角方案,设计了内嵌金属套筒用以降低因装拆磨损带来的树脂精度损失.采用计算流体力学与计算结构力学(CFD/CSD)分析技术,对模型的设计进行了强度校核.加工装配的复合模型在FD-09低速风洞进行了吹风试验.试验结果显示:带舵面偏角的复合模型在迎角α=8°和风速V=70 m/s条件下安全,其气动数据与金属模型吻合良好,具有实用性.相比金属模型,树脂-金属复合模型的加工周期和成本大幅降低,可有效响应飞机设计工作者对模型快速设计和加工的需求,有助于提高飞机设计效率.
As keys for wind tunnel testing,design and fabrication of aircraft model are critical to the development cycle and cost of aircraft.To improve the efficiency of aircraft development,a practical method based on 3D printing technology to design and fabricate model is proposed in the paper.A full low-speed model of one real aircraft is designed and evaluated.The modelis in a plastic-metal hybrid structure,with the 3D printing-made plastic parts as its aerodynamic contour outside and machined metal parts as its backbone inside.V-shaped brackets and shaft-pin mechanisms are adopted to adjust deflection angles of control surfaces.As an attempt to eliminate the precision loss of plastic parts due to abrasion during assembly,metal bushes are custom-designed and inset into the plastic holes.Passing the strength/stiffness calibration based on computational fluid dynamic-computational structure dynamic (CFD/CSD) calculation,the assembled model is tested in the FD-09low-speed wind tunnel.The hybrid model can be used safely in the testing condition when the angle of attack is 8° and the wind speed is 70 m/s.The aerodynamic data from the hybrid model is in consistent well with those from the metal one,which indicates the practicability of the new method to design and fabricate aircraft models.Compared with the metal model,the time and cost concerning design and fabrication of the hybrid model is reduced remarkably,and it can meet the demand of aircraft engineers for the fast and low-cost models and could be promising to improve the development efficiency of aircraft.