Load identification method is investigated for its suitability for drag measurements on a model in impulse combustion facilities. A test system was designed to measure the drag force of a blunt cone model. Dynamic calibration was done to the system by sudden relief of a preload which excited the system. The dynamic parameters were estimated from the response of the balance, and the structural dynamic model of the system was obtained. A ramp-step function plus Fourier series were adopted to model the load history, and the force identification problem was transformed into estimation of parameters of the functions. A two-step solution skill was proposed, which estimated the parameters of the ramp-step function firstly, and then solved the Fourier coefficients by least square method. The number of the Fourier series was determined by forcing the theory response approximating the measured response at low frequency band. The method was firstly validated by numerical simulations. And then, two experiments were carried out in the impulse combustion tunnel. The drag forces of the cone model were identified respectively from the measured responses of the balance, and agreed well with the predictions of the CFD tool.
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References
[1] Sanderson S R, Simmons J M. Drag Balance for Hypervelocity Impulse Facilities[J]. AIAA JOURNAL. 1991, 29(12): 2185-2191.
[2] Tuttle S L, Mee D J, Simmons J M. Drag measurements at Mach 5 using a stress wave force balance[J]. Experiments in Fluids. 1995, 19: 336-341.
[3] Mee D J. Dynamic calibration of force balances for impulse hypersonic facilities[J]. Shock Waves. 2003(12): 443-455.
[4] Robinson M J, Hannemann K, Schramm J M. Design and implementation of an internal stress wave force balance in a shock tunnel[J]. CEAS Space Journal. 2011(1): 45-57.
[5] 乐嘉陵，刘伟雄，贺伟，等. 脉冲燃烧风洞及其在火箭和超燃发动机研究中的应用[J]. 实验流体力学. 2005, 19(1): 1-10.
LE Jia-ling, LIU Wei-xiong, HE Wei, et al. Impulse combustion wind tunnel and its application in rocket and scramjet research[J]. Journal of Experiments in Fluid Mechanics, 2005, 19(1): 1-10.
[6] 刘伟雄，谭宇，毛雄兵，等. 一种新运行方式脉冲燃烧风洞研制及初步应用[J]. 实验流体力学. 2007, 21(4): 59-64.
LIU Wei-xiong, TAN Yu, MAO Xiong-bing, et al. The development and preliminary application of a pulse combustion wind tunnel with new running way[J]. Journal of Experiments in Fluid Mechanics, 2007, 21(4): 59-64.
[7] 贺伟，童泽润，李宏斌. 单模块超燃发动机推力测量天平研制[J]. 航空动力学报. 2010, 25(10): 2285-2289.
HE Wei, TONG Ze-run, LI Hong-bin. Investigation of thrust balance for the single module scramjet[J]. Journal of Aerospace Power, 2010, 25(10): 2285-2289.
[8] 贺伟，于时恩，李宏斌. 高超声速一体化飞行器推阻特性测量研究[J]. 实验流体力学. 2010, 24(2): 65-68.
HE Wei, YU Shi-en, LI Hong-bin. Experimental investigation on thrust drag performance of hyper-sonic integrative vehicle[J]. Journal of Experiments in Fluid Mechanics, 2010, 24(2): 65-68.
[9] Thorby D. Structural Dynamics and Vibration in Practice: An Engineering Handbook[M]. Burlington: Elsevier Ltd, 2008: 53-55.
[10] 韩旭，刘杰，李伟杰，等. 时域内多源动态载荷的一种计算反求技术[J]. 力学学报. 2009, 41(4): 595-602.
HAN Xu, LIU Jie, LI Wei-jie, et al. A computational inverse technique for reconstruction of multisource loads in time domain[J]. Chinese Journal of theoretical and applied mechanics, 2009, 41(4): 595-602.
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