传统金属加工制造测压风洞模型存在难度大、周期长、成本高的问题,利用光固化快速成型技术,可以实现测压风洞模型气动外形-内部孔道的一体化成型制造。设计制作了不同孔径、长度的孔道结构模型,对孔道成型质量和孔道结构参数之间以及孔道半径与设计半径之间的关系进行了研究,并对孔道的气密性以及通气性进行了验证。研究得出了可成型的测压模型孔道结构包括孔径、流道长度以及成型方向3个参数的设计原则以确保孔道成型后能够导通。另外,建立了不同孔径大小的设计补偿原则以减小快速成型制造误差。研究表明,测压孔道气密性、通气性均良好,基于光固化快速成型的一体化测压模型制造技术满足风洞试验要求,可以替代传统模型的测压金属管应用于实际风洞测压试验。
In order to overcome the difficulties with machining the internal channels of a wind tunnel aircraft model for pressure measurements, this paper proposes the use of stereolithography to realize the integrated forming of aerodynamic configurations and internal channels. A series of micro-channels with different diameters and lengths are fabricated, and their forming qualities are examined with an optical microscope system. The diameters of cross-sections are also measured to conform with the radius compensation principle concerning the parameters such as diameter, length and prototyping direction. Air tightness and air permeability of the micro-channels is verified by means of a special test device. Therefore, the channels based on stereolithography meet the requirements of wind tunnel test and they are able to replace the metal tubes.
[1] Springer A, Cooper K. Comparing the aerodynamic characteristics of wind tunnel models produced by rapid prototyping and conventional methods. AIAA-1997-2222, 1997.
[2] Buck G M. Rapid model fabrication and testing for aerospace vehicles. AIAA-2000-0826, 2000.
[3] Aghanajafi S, Adelnia R, Daneshmand S. Production of wind tunnel testing models with use of rapid prototyping methods[J]. WSEAS Transactions on Circuits and Systems, 2006, 5(4): 555-561.
[4] Wohlers T. Rapid prototyping and manufacturing state of the industry. Annual Worldwide Progress Report, Wohlers Associate, Fort Collins, Co., 2006.
[5] Chuk R N, Thomson V J. A comparison of rapid prototyping techniques used for wind tunnel model fabrication[J]. Rapid Prototyping Journal, 1998, 4(4): 185-196.
[6] Azarov Y A, Vermel V D, Kornushenko A V, et al. Experience in laser stereolithography and its application in manufacturing wind-tunnel aerodynamic models of various purposes//Proceedings of the Seventh International Conference on Laser and Laser-Information Technologies. 2002, 4644: 433-440.
[7] Hague R, Mansour S, Saleh N. Material and design considerations for rapid manufacturing[J]. International Journal of Production Research, 2004, 42(22): 4691-4708.
[8] Damljanovic D, Vitic A, Vukovic D. Testing of AGARD-B calibration model in the T-38 transonic windtunnel[J]. Scientific-Technical Review, 2006, 4(2): 52-62.
[9] Quincieu J, Robinson C, Stucker B, et al. Case study: selective laser sintering of the USUSat II small satellite structure[J]. Assembly Automation, 2005, 25(4): 267-272.
[10] 李平, 谢艳, 杨奇磷. 2.4 m风洞大规模测压试验技术及应用[J]. 流体力学实验与测量, 2002, 16(2): 92-96. Li Ping, Xie Yan, Yang Qilin. Test technique and application of large-scale pressure measurement in the 2.4 m×2.4 m transonic wind tunnel[J]. Journal of Experiments in Fluid Mechanics, 2002, 16(2): 92-96. (in Chinese)
[11] 恽起麟. 风洞实验[M]. 北京: 国防工业出版社, 2000. Hui Qilin. Wind tunnel testing[M]. Beijing: National Defense Industry Press, 2000. (in Chinese)
[12] Richard R H, Cliford L R. Rapid prototype wind tunnel model and method of making same: US, 6796171B2 . 2004-09-28.
[13] Hildebrand R J, Eidson R C, Tyler C. Development of a low cost, rapid prototype, lambda wing-body wind-tunnel model. AIAA-2003-3818, 2003.
[14] Tyler C, Braisted W, Higgins J. Evaluation of rapid prototyping technologies for use in wind-tunnel model fabrication. AIAA-2004-6870, 2004.
[15] Heyes A L, Smith D A R. Rapid techniques for wind-tunnel model manufacture. Journal of Aircraft, 2004, 41(2): 413-415.
[16] Zhou Z H, Li D C, Zhang Z Y, et al. Design and fabrication of a hybrid surface-pressure airfoil model based on rapid prototyping [J]. Rapid Prototyping Journal, 2008, 14(1): 57-66.
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