Application of Hartmann-Shack Wavefront Senor in Tomographic Reconstruction of Flow Field

摘要

Light waves passing through the turbulent flow are aberrated by refractive index fluctuations in the flow. Refractive index fluctuations arise from density fluctuations driven by temperature and pressure variations in turbulent flow. Hartmann-Shack wavefront sensor can directly sense these aberrations and also can reconstruct the 3-dimensional structure of the refractive index distribution in a turbulent flow field with tomographic reconstruction technique. A novel method for measuring the 3-dimensional structure of the refractive index distribution in a turbulent flow field combining Hartmann-Shack wavefront sensor with tomographic reconstruction is proposed in this paper. Hartmann-Shack wavefront sensor is used for measurement of an optical wave front after passing through a flow field and the refractive index distribution is reconstructed by computed tomography technique. The principle of the tomographic reconstruction of the flow field based on the Hartmann-Shack wavefront sensor is described briefly. The static symmetric and dynamic asymmetric experimental results are presented. The experimental results indicate that Hartmann-Shack wave-front sensor combining with tomographic reconstruction technique has a potential application for material and flow field investigation regions.