Skin friction measurements using oil film interferometry and Preston tube at subsonic/transonic regime
-
摘要: 在0.6m×0.6m亚跨超声速风洞中，采用油膜干涉测量技术（OFI）和Preston管方法开展了马赫数0.4~0.8下的平板模型表面摩擦应力测量实验研究。模型头部经过椭圆化处理，避免出现流动分离。实验发现：在亚跨声速条件下，两种方法的测量结果具有很好的一致性；油膜粘性对摩擦应力测量结果影响很小；当来流马赫数或总压发生变化时，摩擦应力系数随来流动压或马赫数与雷诺数的乘积（Ma·Re）的增大而减小。在Ma=0.4和0.6时，观测到一种类似斑纹的干涉图像，基于其特性分析，提出以此作为一种转捩判据的设想；在Ma=0.8时，未观察到类似斑纹，根据油膜图像和数值模拟结果判断，模型头部出现了分离泡，边界层由分离诱导转捩。Abstract: Measurements of skin friction on a flat plate model were conducted in the 0.6m×0.6m subsonic/transonic/supersonic wind tunnel. Oil film interferometry (OFI) and Preston tube technique were applied to obtain the skin friction data at Ma=0.4~0.8. In order to avoid flow separation, an elliptical leading edge was employed. Results indicate that the agreement between OFI and Preston tube is very well. Viscosity of oil film has little influence on the skin friction measurement. When the stream's Mach number or the total pressure changes, the skin friction coefficient decreases along with the increase of the dynamic pressure or the product of Mach number and Reynolds number (Ma·Re). A freckle-like interference pattern was observed at Ma=0.4 and 0.6, and an assumption based on the new pattern was proposed to determine the transition location. According to the oil motion and CFD results, a separation bubble rather than the new pattern appears at Ma=0.8, and it is responsible for the transition of boundary layer.
-
Key words:
- OFI /
- Preston tube /
- skin friction /
- transition /
- separation
-
图 5 常压和增压测量结果
Figure 5. Skin frictions measured under conventional and pressured conditions
图 6 摩擦应力系数与q和(Ma·Re)的关系
Figure 6. Relationship between skin friction coefficients and dynamic pressure and (Ma·Re) respectively
图 9 油膜随时间变化情况(红线表示再附位置)
Figure 9. Evolution of oil patch (red line denotes reattaching line)
表 1 实验状态参数
Table 1. Parameters of test conditions
Ma Cf(x=55mm) q/Pa Re(L=0.6m) Ma·Re 0.400 (Conventional) 0.0052 9 740 4.95×106 1.98×106 0.577 (Pressured) 0.0040 26 970 9.90×106 5.71×106 0.600 (Conventional) 0.0045 20 350 7.20×106 4.32×106 0.800 (Conventional) 0.0037 32 830 9.40×106 7.52×106 
下载: 导出CSV
表 2 斑纹图像位置(斑纹中心)
Table 2. Positions of freckle-like interference pattern
Ma Re(L=0.6m) x/mm 0.4 4.95×106 32~33 0.6 9.90×106 27~28
下载: 导出CSV
-
[1] Schrauf G. Status and perspectives of laminar flow[J]. The Aeronautical Journal, 2005, 109(1102):639-644. doi: 10.1017/S000192400000097X [2] Patel V C. Calibration of the Preston tube and limitations on its use in pressure gradients[J]. Journal of Fluid Mechanics, 1965, 23(1):185-208. doi: 10.1017/S0022112065001301 [3] Jerry M Allen. Evaluation of Preston tube calibration equations in supersonic flow[J]. AIAA Journal, 1973, 11(11):1461-1462. doi: 10.2514/3.50610 [4] Bechert D W. Calibration of Preston tubes[J]. AIAA Journal, 1996, 34(1):205-206. doi: 10.2514/3.13048 [5] KimK S, Lee Y, Settles G S. Laser interferometer/Preston tube skin-friction comparison in shock/boundary-layer interaction[J]. AIAA Journal, 1991, 29(6):1007-1009. doi: 10.2514/3.10695 [6] Kwak D Y, Yoshida K, Noguchi M, et al. Boundary layer transition measurement using Preston tube on NEXST-1 flight test[C]//Proc of 25th AIAA Applied Aerodynamics Conference. 2007. [7] DriverD M, Drake A. Skin friction measurements using oil film interferometry in the 11' transonic wind tunnel at NASA Ames[C]//Proc of 42nd AIAA Aerospace Sciences Meeting and Exhibit. 2004. [8] Ehrmann R S, Lichtwardt J A, Paciano E N, et al. Global skin friction measurements on a circulation control airliner in the NFAC[C]//Proc of 51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition. 2013. [9] Schülein E. Optical skin friction measurements in short-duration facilities[C]//Proc of 24th AIAA Aerodynamic Measurement Technology and Ground Testing Conference, Portland. 2004. [10] Garrison T J, Ackman M. Development of a global interferometer skin-friction meter[J]. AIAA Journal, 1998, 36(1):62-68. doi: 10.2514/2.352 [11] 代成果, 张长丰, 黄飓, 等.高超声速表面摩擦应力油膜干涉测量技术研究[J].实验流体力学, 2012, 26(2):68-71, 85. http://www.syltlx.com/CN/abstract/abstract10563.shtmlDai C G, Zhang C F, Huang J. et al. Hypersonic skin friction stress measurements using oil film interferometry technique[J]. Journal of Experiments in Fluid Mechanics, 2012, 26(2):68-71, 85. http://www.syltlx.com/CN/abstract/abstract10563.shtml [12] 刘志勇, 张长丰, 代成果.表面摩擦应力油膜干涉测量技术在Ma=8的应用[J].实验流体力学, 2015, 29(6):74-78. http://www.syltlx.com/CN/abstract/abstract10893.shtmlLiu Z Y, Zhang C F, Dai C G. Application of oil film interfero-metry technique at Ma=8[J]. Journal of Experiments in Fluid Mechanics, 2015, 29(6):74-78. http://www.syltlx.com/CN/abstract/abstract10893.shtml [13] 丁超, 史志伟, 玉曜瑜.基于油膜干涉法的表面摩擦应力测量技术研究[J].实验力学, 2011, 26(6):707-714. http://d.old.wanfangdata.com.cn/Periodical/sylx201106011Ding C, Shi Z W, Yu Y Y. Study of skin friction stress mea-surement technique based on oil film interferometry[J]. Journal of Experimental in Fluid Mechanics, 2011, 26(6):707-714. http://d.old.wanfangdata.com.cn/Periodical/sylx201106011 [14] 耿子海, 史志伟, 金启刚.油膜干涉测量翼型壁面摩阻低速风洞试验技术[J].空气动力学学报, 2016, 34(1):80-85. http://d.old.wanfangdata.com.cn/Periodical/kqdlxxb201601014Geng Z H, Shi Z W, Jin Q G. Invetigation of skin-friction measurements using oil-film interferometry on airfoil wall in low speed wind tunnel[J]. Acta Aerodynamica Sinica, 2016, 34(1):80-85. http://d.old.wanfangdata.com.cn/Periodical/kqdlxxb201601014 [15] Bhatia D, Yang G J, Sun J, et al. Effects of different geometries on boundary layer transition[C]//Proc of 54th AIAA Aerospace Sciences Meeting. 2016. [16] Squire L C. The motion of a thin oil sheet under the steady boundary layer on a body[J]. Journal of Fluid Mechanics, 1961, 11:161-179. doi: 10.1017/S0022112061000445 [17] Fenter F W, Stalmach C J Jr. The measurement of local turbulent skin friction at supersonic speeds by means of surface impact pressure probes[R]. Defense Research Laboratory Report, No. 392, CM-878, 1957. [18] Naughton J W. Multiple-image oil film interferometry[C]//Proc of 46th AIAA Aerospace Sciences Meeting and Exhibit. 2008. [19] Naughton J W, Liu T. Photogrammetry in oil-film interferometry[J]. AIAA Journal, 2007, 45(7):1620-1629. doi: 10.2514/1.24634 -
点击查看大图
图(10) / 表(2)
计量
- 文章访问数: 234
- HTML全文浏览量: 109
- PDF下载量: 14
- 被引次数: 0
