| 曲培树,宋一中.应用非线性自适应迭代重建算法层析热流场[J].光电子激光,2014,(8):1641~1646 |
| 应用非线性自适应迭代重建算法层析热流场 |
| Diagnosing thermal flow field with non-linear auto-adjusting iterative reconstruction technique |
| 投稿时间：2014-02-15 |
| DOI： |
| 中文关键词: 非线性自适应迭代重建算法(NAIRT) 偏折层析 傅立叶变换 空间滤波 诊断热流场 |
| 英文关键词:non-linear auto-adjusting iterative reconstruction technique (NAIRT) deflecti on tomography Fourier transform spatial filtering diagnosing thermal flow fie ld |
| 基金项目: |
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| 摘要点击次数: 1654 |
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| 中文摘要: |
| 为了提高光学计算层析技术(OCT)对热流场的 诊断能力,采用非线性自适应 迭代重建算法(NAIRT)重建热流场的截面温度分布。应用准直激光束扫描 待测热流场,应用双光栅衍射获得莫尔条纹。为了获得层析投影数据,对莫尔条 纹进行了包括傅立叶变换、数字滤波、逆傅立叶变换、相位分 析和截面提取,最终获得扫描光线偏折角信息,即层析投影。应用NAIRT对偏折角 迭代重建热流场的折射率分布,应用G_D变换进一步转换为温度分布,从而 获得热流场的截面温度层析信息。结果表明,NAIRT不仅能精确重建实验热流场的截 面温度分布,还可以层析热流场的任意截面。所以,NAIRT能够有效诊断热流场。 |
| 英文摘要: |
| In order to improve the practicability using the optical computer tomo graphy (OCT) to diagnose thermal flow fields,non-linear auto-adjusting iterative reco nstruction technique (NAIRT) is proposed and applied to reconstr uct the temperature distribution on a cross section of a thermal flow field.The field is detected with a collimated laser beam.After passing through the field,the collimated la ser beam disturbed by the field is diffracted by two identical equi -spaced Ronchi gratings.The diffracted patterns were projected onto a screen,so we can get d eflected Moiré fringes.To obtain the phase shift data,the Moiré patterns are analyzed with a series of mathema tical transforms,including Fourier transformation,filtering,inverse Fourier transf ormation and reconstruction with the positive first order spectra,and so on.The phase shi ft data are transformed into deflected angles,namely,the optical projections.The refractive index distribution is reconstructed by NAIRT with the deflected angles,then is transformed into an air density distribution,and finally transformed into the temperature distribution. As a result, NAIRT could effectively reconstruct the temperature distribution on a cross sect ion of the field.With the same processing methods,NAIRT could effectively reconstruct arbit ary cross-sectional temperature distribution of the field.Therefore,NAIRT could ef fectively diagnose the field. |
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