Block error rate performance of subcarrier intensity modulation based optical wireless communication systems is analysed over Gamma–Gamma and lognormal atmospheric turbulence channels. The analysis is applicable to non-coherent binary modulations and coherent binary phase shift keying. The special cases of K-distributed strong turbulence channel and negative exponential turbulence channel are a...

Because of the multi-scale nature of hurricanes, the proposed large-eddy simulation work is also a challenging computational problem. A three-dimensional research cloud model (CM1) with horizontal grid stretching capability is used to conduct convergence test. The Weather Research and Forecasting (WRF) model is used as a weather-prediction model to examine the eddy-diffusion coefficients obtain...

Three series of experiments were conducted to study the effect of Reynolds number, near-wall perturbation and background turbulence on the characteristics of smooth open channel flows. Measurements were carried out using a laser Doppler anemometer. The variables of interest include the mean velocity, the turbulence intensity, probability density distribution and Gram-Charlier series coefficient...

Wen-Jei Yang Department of Mechanical Engineering and Applied Mechanics, The University of Michigan, Ann Arbor, Michigan 1 A n experimental study is performed to investigate the pressure drop distribution and turbulence intensity for airflow through a stack of parallel plates with periodic interruptions. The interrupted surfaces are constructed in an offset-strip f6rm and a perforated form. Hot...

We present a new model of turbulence spreading in magnetically confined plasma. A basic question in turbulence spreading is how to sustain finite amplitude fluctuations in a stable subcritical region, where linear dissipation of the turbulence is strong? The answer to this question relies on a consistent treatment of mesoscale temperature profile corrugation and microscale turbulence. We argue ...

Global gyrokinetic simulations have revealed an important nonlinear flow generation process due to the residual stress produced by electrostatic turbulence of ion temperature gradient ITG modes and trapped electron modes TEMs . In collisionless TEM CTEM turbulence, nonlinear residual stress generation by both the fluctuation intensity and the intensity gradient in the presence of broken symmetr...

We present the first evidence of the direct influence of gas turbulence on the shear instability of a planar air-water mixing layer. We show with two different experiments that increasing the level of velocity fluctuations in the gas phase continuously increases the frequency of the instability, up to a doubling of frequency for the largest turbulence intensity investigated. A modified spatiote...

Analytical formulas are derived for the average intensity, the root-mean-square (rms) angular width, and the M2-factor of Laguerre-Gaussian correlated Schell-model (LGCSM) beam propagating in non-Kolmogorov turbulence. The influence of the beam and turbulence parameters on the LGCSM beam is numerically calculated. It is shown that the quality of the LGCSM beam can be improved by choo...