Comparative analysis of numerical simulation techniques for incoherent imaging through atmospheric turbulence

2016 ◽  
Author(s):  
Svetlana L. Lachinova ◽  
Mikhail A. Vorontsov ◽  
Daniel A. LeMaster ◽  
Matthew E. Trippel
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Atmospheric Turbulence ◽  
Simulation Techniques ◽  
Incoherent Imaging

Comparative analysis of numerical simulation techniques for incoherent imaging of extended objects through atmospheric turbulence

2017 ◽  
Vol 56 (7) ◽  
pp. 071509 ◽  
Author(s):  
Svetlana L. Lachinova ◽  
Mikhail A. Vorontsov ◽  
Grigory A. Filimonov ◽  
Daniel A. LeMaster ◽  
Matthew E. Trippel
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Atmospheric Turbulence ◽  
Simulation Techniques ◽  
Incoherent Imaging

Simulation and Modeling of Turbulent Flows

1996 ◽  
Keyword(s):  
Numerical Simulation ◽  
Turbulent Flow ◽  
Turbulent Flows ◽  
Simulation And Modeling ◽  
Simulation Techniques ◽  
Rational Development ◽  
Group Methods ◽  
Turbulent Closure ◽  
The Subject ◽  
Renormalization Group Methods

This book provides students and researchers in fluid engineering with an up-to-date overview of turbulent flow research in the areas of simulation and modeling. A key element of the book is the systematic, rational development of turbulence closure models and related aspects of modern turbulent flow theory and prediction. Starting with a review of the spectral dynamics of homogenous and inhomogeneous turbulent flows, succeeding chapters deal with numerical simulation techniques, renormalization group methods and turbulent closure modeling. Each chapter is authored by recognized leaders in their respective fields, and each provides a thorough and cohesive treatment of the subject.

Numerical Simulation of Shock Wave in Air Based on FCT Method

2013 ◽  
Vol 397-400 ◽  
pp. 270-273
Author(s):  
Ying Li ◽  
Xiao Bin Li ◽  
Yu Wang ◽  
Wei Zhang
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Comparative Analysis ◽  
Numerical Method ◽  
Blast Wave ◽  
Empirical Formula ◽  
Godunov Method ◽  
Numerical Accuracy

Blast wave is numerical simulated based on FCT method. According to the comparative analysis, taking Henrych empirical formula as a standard, FCT method is more accuracy than Godunov method. Moreover, it has been found that the numerical accuracy is insufficient when the distance is small, it is necessary to develop and modify the numerical method continuously.

scholarly journals A method of generating a random optical field using the Karhunen-Loeve expansion to simulate atmospheric turbulence

2020 ◽  
Vol 44 (1) ◽  
pp. 53-59
Author(s):  
S.N. Khonina ◽  
S.G. Volotovskiy ◽  
M.S. Kirilenko
Keyword(s):  
Numerical Simulation ◽  
Correlation Function ◽  
Atmospheric Turbulence ◽  
Random Environment ◽  
Random Medium ◽  
Optical Field ◽  
Phase Singularity ◽  
Vortex Beams ◽  
Simulation Results ◽  
Random Field Generation

It is proposed to use the random field generation in the numerical simulation of the propagation of radiation through a random medium using method based on the Karhunen–Loeve expansion with various types of correlation operators to describe turbulence simulators. The properties of the calculated simulators of a random medium with a Gaussian correlation function were investigated in modeling the propagation of Laguerre-Gaussian vortex beams. The simulation results showed that an increase in the order of the optical vortex leads, as in the experiment, to lower stability of the phase singularity of the beams to random optical fluctuations. The similarity of the simulation results and the optical experiments indicates the promise of the proposed approach for the synthesis of random environment simulators.

Numerical Simulation on Deformation Features and Filling Efficiency of Channel Goaf Foundation

2013 ◽  
Vol 353-356 ◽  
pp. 3707-3712
Author(s):  
Zhi Dong Zhou ◽  
Hong Bo Zhang ◽  
Xiu Guang Song ◽  
Hong Ya Yue
Keyword(s):  
Numerical Simulation ◽  
Comparative Analysis ◽  
Comprehensive Analysis ◽  
Obvious Effect ◽  
Before And After ◽  
Check Gate ◽  
Deformation Features ◽  
Natural Foundation ◽  
The Stability

For analyzing and evaluating the deformation features of channel goaf foundation and its effect on superstructure, according to the foundation reinforcement engineering of Ji-Liang Channel Check Gate, the comparative analysis on the differential settlement between the unfavorable foundation and natural foundation was performed by numerical simulation with FLAC3D. The computer results showed that the present foundation had obvious effect on the stability and security of the superstructure, so the engineering treatment are needed. Based on technical-economic comprehensive analysis among three treatment methods for strengthening the channel golf foundation with different kinds of filling, the reasonable method is put forward in this paper. By comparing mechanical characteristic of flashboard in channel goaf before and after strengthening, we confirmed the foundation stability of channel goaf and the security of the ground building which can satisfy the long term usage requirements.

A Comparison of Self-Rectifying Turbines for OWC Based Wave Energy Power Extracting Device Using Numerical Simulation

2002 ◽  
Author(s):  
A. R. Ansari ◽  
H. B. Khaleeq ◽  
A. Thakker
Keyword(s):  
Numerical Simulation ◽  
Wave Energy ◽  
Sea Water ◽  
Time History ◽  
Flow Conditions ◽  
Wells Turbine ◽  
Impulse Turbine ◽  
Simulation Techniques ◽  
Simple Geometry ◽  
Wide Range

This paper presents a comparison of self-rectifying turbines for the Oscillating Water Column (OWC) based Wave Energy power extracting device using numerical simulation. The two most commonly used turbines for OWC based devices, the Impulse and the Wells turbines were evaluated under real sea simulated conditions. Assuming the quasi-steady condition, experimental data for both 0.6m turbines with 0.6 hub to tip ratio was used to predict their behavior under real sea conditions. The real sea water surface elevation time history data was used to simulate the flow conditions using standard numerical simulation techniques. A simple geometry of the OWC was considered for the simulation. The results show that the overall mean performance of an Impulse turbine is better than the Wells turbine under unsteady, irregular real sea conditions. The Impulse turbine was observed to be more stable over a wide range of flow conditions. This paper reports the comparison of performance characteristics of both these turbines under simulated real sea conditions.

scholarly journals The Error in Solar-Diameter Measurements Induced by Atmospheric Turbulence

2001 ◽  
Vol 24 (3) ◽  
pp. 230-230
Author(s):  
Lyes Lakhal
Keyword(s):  
Numerical Simulation ◽  
Atmospheric Turbulence ◽  
Atmospheric Effects ◽  
Diameter Measurement ◽  
Time Constants ◽  
Know How ◽  
Solar Diameter ◽  
Recorded Data ◽  
Good Agreement

Diameter measurements performed with the solar astrolabe are affected by atmospheric effects. In order to deduce significant astrophysical results, it is necessary to know how these effects contribute to the error of diameter measurement. For this purpose, a numerical simulation was developed leading to a law of error behaviour with observing conditions. In order to validate these results, recorded data obtained at the Calern observatory astrolabe (France) during the period 1996 – 1997 are used. A good agreement is observed with the simulation, which permit salso to give access to daily atmospheric time constants. (Co-author is A. Irbah, Algeria.)

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