Regularizing Shear Layer for Adaptive Optics Control Applications
نویسندگان
چکیده
This paper uses a discrete-vortex code to examine a shear layer’s response to forcing at its origin. The code and its thermodynamic overlay have been used in previous studies to predict the optically-aberrating characteristics of relatively-high-Mach-number, subsonic shear layers that can be classified as weakly compressible. The results reported in this study are again directed toward the shear layer’s optical characteristics; however, the intent was to use forcing to create periodic aberrating fields, referred to as “regularized” shear-layer aberrations. The study shows that the use of single-frequency forcing produces a regularized shear layer for distances preceding the point where the unforced shear layer’s natural frequency occurs. In the case of the forced shear layer, a greater thickness is produced closer to its point of origin until collapsing onto the unforced shear layer thickness past the point of regularization. The aberration periodicity is shown to have lower robustness toward the furthest downstream extent of regularization due to uncontrolled pairing. This region is made more regular by applying both fundamental and subharmonic forcing at the shear layer’s origin; however, such subharmonic forcing is sensitive to the phasing of the fundamental to that of the subharmonic.
منابع مشابه
Phase-Locked-Loop Adaptive-Optic Controller and Simulated Shear Layer Correction
An alternative adaptive-optic controller, using both flow control and a phase-lock-loop control strategy, has been designed to overcome bandwidth limitations inhibiting current adaptive-optic controllers. A discrete-vortex code and weakly compressible model were used to simulate high-speed shear layer adaptive-optic corrections based upon the proposed phase-lock-loop controller given a range of...
متن کاملPhotonic Materials and Devices
Our recent advances in solid-state optoelectronic materials and devices will be reviewed. In the area of glass optics, fabrication of novel microstructured and multi-core fibers and their use in realizing single mode lasers will be summarized. In organic and plastic optics, photorefractive polymers for 3D display applications and nonlinear optical polymers for high speed modulators in RF photon...
متن کاملAnalysis of the improvement in sky coverage for multiconjugate adaptive optics systems obtained using minimum variance split tomography.
The scientific utility of laser-guide-star-based multiconjugate adaptive optics systems depends upon high sky coverage. Previously we reported a high-fidelity sky coverage analysis of an ad hoc split tomography control algorithm and a postprocessing simulation technique. In this paper, we present the performance of a newer minimum variance split tomography algorithm, and we show that it brings ...
متن کاملApplications of higher order shear deformation theories on stress distribution in a five layer sandwich plate
In this paper, layerwise theory (LT) along with the first, second and third-order shear deformation theories (FSDT, SSDT and TSDT) are used to determine the stress distribution in a simply supported square sandwich plate subjected to a uniformly distributed load. Two functionally graded (FG) face sheets encapsulate an elastomeric core while two epoxy adhesive layers adhere the core to the face ...
متن کامل