A reconstruction algorithm of temperature field taking into account the bending of sound wave paths

When a sound wave passes through a non-uniform temperature field,the sound wave path will bend due to refraction.In order to improve the reconstruction accuracy of un-uniform temperature fields by acoustic Computer Tomography,a reconstruction algorithm considering the bending of sound wave paths is proposed.First,obtain a reconstruction temperature field by the least-squares method without considering the bending of sound wave paths.Second,find the eigenrays between the sound transmitters/receivers in the reconstruction field by using the triangular forward deployment method for sound ray tracing and shooting-interpolation method for evaluating the emergent angle of eigenrays.Third,establish the relationship between the acoustic travel-times over the eigenrays and the temperature distribution.Last,reaHze the reconstruction of temperature field by the least-squares method with considering the bending of sound wave paths.The reconstruction results of single-peak and double-peak model temperature fields show that the method used for finding eigenrays is simple in calculation and fast in execution;the reconstruction accuracy can be improved obviously by considering the bending of sound wave paths.Thus the reconstruction algorithm proposed is more appropriate for reconstruction of actual temperature fields.