A fast ray casting method for sound refraction at shear layers

2016 ◽  
Author(s):  
Ennes Sarradj
Keyword(s):  
Shear Layers ◽  
Ray Casting ◽  
Casting Method

A fast ray casting method for sound refraction at shear layers

2017 ◽  
Vol 16 (1-2) ◽  
pp. 65-77 ◽  
Author(s):  
Ennes Sarradj
Keyword(s):  
Ray Tracing ◽  
Shear Layers ◽  
Computational Effort ◽  
Microphone Arrays ◽  
Wind Tunnels ◽  
Ray Casting ◽  
Casting Method ◽  
General Application ◽  
Interpolation Technique ◽  
Open Test

The application of microphone arrays for aeroacoustic measurements in wind tunnels with an open test section requires to consider the sound refraction at the shear layer. Several methods are available for this that are either applicable to special scenarios such as planar or cylindrical thin shear layers or that require considerable computational effort. The paper concerns a new method for general application—ray casting—that is based on a ray tracing method. Ray tracing is briefly revisited and it is shown that the computational effort becomes quite high especially for large mapping grids. The ray casting approach with its interpolation technique is introduced. A time reversal technique is the key to make this approach very efficient and fast. Finally, the approach is demonstrated using two example results from simulation and from a practical measurement.

Ray-casting method to assess the quality of segmented surfaces from 3D images

2017 ◽  
Author(s):  
J. P. D'Amato ◽  
M. Del Fresno ◽  
C. Garcia Bauza ◽  
M. Vénere
Keyword(s):  
Ray Casting ◽  
Casting Method ◽  
3D Images

Practical considerations for ray casting shear layer corrections

2021 ◽  
pp. 1475472X2110526
Author(s):  
Todd Schultz
Keyword(s):  
Shear Layer ◽  
Ray Tracing ◽  
Acoustic Waves ◽  
Phased Arrays ◽  
Acoustic Propagation ◽  
Wind Tunnels ◽  
Computational Time ◽  
Propagation Time ◽  
Ray Casting ◽  
Casting Method

Aircraft noise reduction technology development has been aided by the use of acoustic phased arrays to identify component-level locations of noise sources. Acoustic phased arrays are commonly used in both closed-wall and open-jet wind tunnels, thus requiring accurate acoustic propagation models to focus the array. In particular, open-jet wind tunnels have complex flow fields including a free shear layer that the acoustic waves must propagate through. A method using ray tracing is reviewed and an enhancement proposed to reduce the computational time for cases requiring a large number of rays. The proposed reduced ray casting method uses ray tracing to the extreme edges of the region of interest and limits all casted acoustic rays to within that region. The results showed that a hemispherical spiral discretization had lower error in the estimated acoustic propagation time than uniform angular discretization. The proposed reduced ray casting method showed similar accuracy as the original ray casting method but with improvement in the computational times when the number of cast rays was greater than 3200 as needed for modeling acoustic propagation in larger industrial sized open-jet wind tunnels.

An efficient Ray Casting method for terrain visualization

2011 ◽  
Author(s):  
Jianxin Luo ◽  
Bai Wang ◽  
Qin Feng ◽  
Guiqiang Ni ◽  
Guyu Hu ◽  
...  
Keyword(s):  
Ray Casting ◽  
Casting Method ◽  
Terrain Visualization
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