Research on BER performance of the OAM-SK FSO communication system with wavefront phase correction by Shuang LI, Ping WANG, Tao LIU, Yuting PAN, Wei WANG

“…On the basis of Gerchberg-Saxton (GS) algorithm and angular-spectrum theory, an improved wavefront phase correction algorithm to the Laguerre-Gaussian (LG) beams was proposed for the orbital angular momentum-shift keying (OAM-SK) modulation-based free space optical (FSO) communication system under weak atmospheric turbulence.The light field distributions of the probe beam at transmitter and receiver were regarded as the input of the improved wavefront phase correction algorithm.And the correction phase mask was iteratively calculated to correct the distorted LG beams, thereby alleviating the inter-model crosstalk caused by atmospheric turbulence.Simulation results show that the improved wavefront phase correction algorithm is superior to the conditional GS algorithm.And with the increase of the refractive-index structure parameter, the bit error rate (BER) performance of the OAM-SK FSO communication system is significantly improved.…”
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Strongly Magnetized Accretion with Low Angular Momentum Produces a Weak Jet by Alisa Galishnikova, Alexander Philippov, Eliot Quataert, Koushik Chatterjee, Matthew Liska

“…Black hole-driven feedback in the form of magnetic eruptions and jets triggers magnetized turbulence in the surrounding medium. We find that when the Bondi radius exceeds a certain value relative to the black hole’s gravitational radius, this turbulence restricts the subsequent inflow of magnetic flux, strongly suppressing the strength of the jet. …”
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Numerical Simulation of Bubble Coalescence and Break-Up in Multinozzle Jet Ejector by Dhanesh Patel, Ashvinkumar Chaudhari, Arto Laari, Matti Heiliö, Jari Hämäläinen, Kishorilal Agrawal

“…The realizable k-ε turbulence model is used in CFD code in three-dimensional computational domains. …”
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CFD Analysis of the First-Stage Rotor and Stator in a Two-Stage Mixed Flow Pump by Steven M. Miner

“…The code solves the 3D Reynolds-averaged Navier-Stokes equations in rotating and stationary cylindrical coordinate systems for the rotor and stator, respectively. Turbulence effects are modeled using a standard k−ε turbulence model. …”
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Project sustainability in the conditions of digitalization by M. V. Lubenets, S. M. Sycheva

“…As a result of the research, a new approach has been developed to assess the sustainability of projects based on a strategic model that takes into account modern challenges of uncertainty and turbulence. The study prospects lie in practical use of developed integrated approach for models’ formation for the sustainable implementation of projects in various business areas.…”
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Research on the system error performance of coherent orthogonal frequency division multiplexing system with M-distribution in satellite-to-ground laser communication by Yi WANG, Yaping WANG

“…In order to alleviate the influence of atmospheric turbulence on the performance of satellite-to-ground laser communication system,based on the M-distribution atmospheric channel model,a multi-carrier coherent orthogonal frequency division multiplexing (OFDM) modulation system was proposed for uplink and downlink in the satellite-to-ground laser communication.The closed-form expression of bit error rate (BER) of coherent OFDM modulation system was derived.The relationship between the zenith angle,receiving aperture,signal-to-noise ratio (SNR),optimal beam divergence angle,and optimal transmission radius and the BER were studied under weak,and strong atmosphere turbulence,and compared with binary coherent differential phase shift keying (DPSK) modulation.Both the theory and the simulation results show that compared with coherent DPSK modulation,the bit error performance of the coherent OFDM modulation system in the satellite-to-ground laser communication system is better.…”
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Adaptive Fault-Tolerant Control for Flight Systems with Input Saturation and Model Mismatch by Man Wang, Jianying Yang, Nan Li

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Performance analysis of dual-hop PLC-FSO communication system by Shenghai CHEN, Xiaoqin YAN, Sai LI, Liang YANG

“…A dual-hop power line communication and free-space optical communication (PLC-FSO) system was proposed, where an amplify-and-forward (AF) relay was applied to help the signal transmission between the PLC link and the FSO link.More specifically, it was assumed that the PLC link was affected by both additive background noise and impulsive noise, and the channel fading followed log-normal distribution, while the fading induced by the atmospheric turbulence in the FSO link followed a Gamma-Gamma distribution, and the effect of pointing errors was also considered.Based on this model, closed-form expressions for the outage probability, bit error rate, and the channel capacity were derived.In addition, asymptotic analysis for the outage probability and BER, and upper bound expression for the channel capacity were presented.Finally, the accuracy of the analytical results was justified through Monte-Carlo simulations.The results show that the system outage probability decreases as the pointing error parameter increases and the smaller the PLC link impulse noise, the lower the bit error rate.The system capacity increases as the turbulence intensity decreases.…”
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Simulation Investigation on the Flow and Mixing in Ducts of the Rotary Energy Recovery Device by Kai Liu, Lixing Zheng

“…It was found that vortices significantly affected the mixing performance, and the detached vortex could lead to high turbulence and mixing in the duct. Suppressing the vortex shedding may reduce the flow turbulence and gain a lower volumetric mixing rate.…”
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Dynamic processes during accretion into a black hole by G. S. Bisonvatyi-kogan

“…Sources of turbulence in the accretion disc are discussed, including nonlinear hydrodynamic turbulence, convection and magnetic filed role. …”
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Numerical Simulations of the Flame of a Single Coaxial Injector by Victor P. Zhukov, Markus Feil

“…In the first test case, the two-dimensional axisymmetric simulations are performed using the shear-stress turbulence (SST) model. Due to the dominant flow unsteadiness in the second test case, the turbulence is modeled using transient SAS (Scale-Adaptive Simulation) model. …”
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Vertical Shear Instability in Thermally Stratified Protoplanetary Disks. II. Hydrodynamic Simulations and Observability by Han-Gyeol Yun, Woong-Tae Kim, Jaehan Bae, Cheongho Han

“…The saturated turbulence is more pronounced near the disk surfaces than at the midplane. …”
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Recent Studies in Turbine Blade Cooling by Je-Chin Han

“…For internal cooling, this presentation focuses on the effect of rotation on rotor blade coolant passage heat transfer with rib turbulators and impinging jets. The computational flow and heat transfer results are also presented and compared to experimental data using the RANS method with various turbulence models such as k-ε, and second-moment closure models. …”
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Multi-GPU Development of a Neural Networks Based Reconstructor for Adaptive Optics by Carlos González-Gutiérrez, María Luisa Sánchez-Rodríguez, José Luis Calvo-Rolle, Francisco Javier de Cos Juez

“…Aberrations introduced by the atmospheric turbulence in large telescopes are compensated using adaptive optics systems, where the use of deformable mirrors and multiple sensors relies on complex control systems. …”
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Design considerations for wavefront sensing with self-referencing interferometers in adaptive optics systems by MacGillivray Alexander C., Hristovski Ilija R., Jenne Matthias F., Reeves Andrew P., Mata Calvo Ramon, Holzman Jonathan F.

“…The SRI is developed to aid adaptive optics (AO) control, via deformable mirrors, in correcting wavefront error from atmospheric turbulence in (laser-based) free-space optical communication links. …”
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Prediction of Pollutant Emissions from Bluff-Body Stabilised Nonpremixed Flames by Nelu Munteanu, Shokri M. Amzaini

“…The reason for these discrepancies is that the flamelet model is not adequate to capture the finite-rate chemistry effects and shear turbulence specifically, for species with a slow time scale such as nitrogen oxides.…”
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Effect of Pitch Angle on Structural and Aerodynamic Characteristics of Vertical-Axis Wind Turbines (VAWTs) Using Leading-Edge Protuberance Blades by Karthikvel Elangovan, S. Nadaraja Pillai

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A Comparative CFD Study on Simulating Flameless Oxy-Fuel Combustion in a Pilot-Scale Furnace by Mersedeh Ghadamgahi, Patrik Ölund, Tomas Ekman, Nils Andersson, Pär Jönsson

“…A three-dimensional CFD model was developed and the validity of using different submodels describing turbulence and chemical reactions was evaluated. The standard k-ε model was compared with the realizable k-ε model for turbulence, while Probability Density Function (PDF) with either chemical equilibrium or the Steady Laminar Flamelet Model (SLFM) was evaluated for combustion. …”
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Using Flow 3D Simulation, Multiple Nonlinear Regression Approach, and Artificial Neural Network Approach Approaches to Study the Behavior of Vertical Drop Structures by Shaikhli Hasan Al, Mohammed Sarah Hashim, Al-Khafaji Zainab

“…Key flow parameters, such as downstream depth, pool depth, and energy loss, were calculated and validated against experimental data. Various turbulence models and grid configurations were assessed. …”
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Numerical analysis of collision mechanism that causes particle tribocharging in dry powder inhaler by Ryosuke Mitani, Muhammad Aiman bin Mohd Nor, Takuto Iinuma, Tatsuhiro Mori, Tomoaki Okuda

“…These results suggest that optimum turbulence kinetic energy is necessary to reduce particle aggregation and improve the delivery efficiency of DPIs to the human lungs. …”
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