An expression of arrival_angle fluctuation spectrum for the collimated light propagating through homogeneous turbulent media is developed, when the effects of filter of lens and the real fluctuation of velocity on measuring the spectrum of the arrival_angle fluctuation is taken into account.

The calculating results are that: high_frequency and low_frequency end of arrival_angle fluctuation spectrum will decay fast when the aperture of lens is small, but they will decay slowly when the aperture is large;

This model treats fluctuation of particle movement as a random Fourier series based on gas flow fluctuation spectrum and hence is known as the fluctuation-spectrum-random-trajetory(FSRT)model.

In this paper theoretical wall pressure fluctuation spectrum calculated by Rapid Distortion Theory was used to predict the effect of circular transducer size on the measured statistical properties of wall pressure fluctuation signals. It was found that the measured onedimensional spectrum has a significant decreaSe at hish wave numbers due to attenuation by the finite size of the transducer, and wall pressure fluctuahon intensity decreases with the increase of the transducer size.

EFFECT OF CIRCULAR TRANSDUCER SIZE ON WALL PRESSURE FLUCTUATION SIGNALEFFECTOFCIRCULARTRANSDUCERSIZEONWALLPRESSUREFLUCTUATION. .

In the same time the K e two equation model and the fluctuation spectrum random trajectory model(FSRT model) are used to stimulate the flow and heat transfer of gas phase and solid phase respectively.

Fatigue crack growth rate has been measured for the API 5L X52 steel and its welded joints using CT specimens. Based on the operational pressure fluctuation spectrum acquired at pump station discharges,service life of the pipeline is estimated.

用紧凑拉伸 ( CT)试件 ,测试了 API 5 L X5 2管材及焊管接头的疲劳裂纹扩展速率 ,根据泵站的载荷谱 ,估算了管线的服役寿命。

Fluctuation spectrum in an exactly solvable model with dissipation: A new model of the Flicker noise

General expressions have been derived for the phase fluctuation spectrum of a short-wave signal reflected at the ionospheric layer with an arbitrary regular permittivity profile and given spectrum of inhomogeneities.

Determination of frequency instability on the basis of the signal phase fluctuation spectrum

We also show how the fluctuation spectrum of two quantities such as the saturation and the reaction rate can be drastically different, the first being universal and the other sensitive to the geometry of the substrate.

The predictions for the one-electron density, the static structure factor, and the long-wavelength charge fluctuation spectrum are compared to the results of extensive molecular dynamics simulations.

The magnitude of temperature fluctuation spectrum ΦT(K0) or temperature structure coefficient G2T can be directly measured by acoustic radar. In atmosphere, the spectrum scale is very wide, so in atmospheric boundary layer the magnitude ΦT(K0) or G2T measured by acoustic radar is a random variable obeying the logarithmic normal distribution.We analysed the frequency spectra of ΦT(K0) and found that in the frequency range of 10-3-3 × 10-3 c/s there is a maximum value vange of energy. Between the maximum...

The magnitude of temperature fluctuation spectrum ΦT(K0) or temperature structure coefficient G2T can be directly measured by acoustic radar. In atmosphere, the spectrum scale is very wide, so in atmospheric boundary layer the magnitude ΦT(K0) or G2T measured by acoustic radar is a random variable obeying the logarithmic normal distribution.We analysed the frequency spectra of ΦT(K0) and found that in the frequency range of 10-3-3 × 10-3 c/s there is a maximum value vange of energy. Between the maximum value range and high-frequency range exists a sharp transitional band of energy. At past years some meteorologists usually considered that there is a gap in the meso-scale range of spectra. In this articale, it is shown that at meso-scale range, whenever in stable or unstable conditions there is a cyclic activity of time scale from several minites to more ten minites and it makes a great contribution to the energy. This phenomena may be of importance for the theoritical research of the atmospheric turbulence. Since in the atmosphere the spectral range is very wide, we must select correctly the length of mean time in the measurement of meteorological elements or other physical parameters to obtain their stable means.

The spectrum width of photocurrent of LDA includes several different kinds of Doppler ambiguity broadening. The velocity fluctuation spectrum of turbulent flow can not be obtained from the photocurrent spectrum with broadening, unless all the Doppler ambiguity broadening can be determined or estimated. The mutualbeating contributions from two scattering particles play an important role in spectrum broadening, which varies with the spatial coherence condition. The broadening from mutual-beating...

The spectrum width of photocurrent of LDA includes several different kinds of Doppler ambiguity broadening. The velocity fluctuation spectrum of turbulent flow can not be obtained from the photocurrent spectrum with broadening, unless all the Doppler ambiguity broadening can be determined or estimated. The mutualbeating contributions from two scattering particles play an important role in spectrum broadening, which varies with the spatial coherence condition. The broadening from mutual-beating is called coherence broadening △Vcoh. If the particle pairs are situated in the "coherence volume", the mutual-beating will give a beat frequency in the output of the photodetector. The lasting time of the mutual-beating is called the effective-transit time of the scattering particle pairs, △teff, which is corresponding to the coherence broadening. The mutual-beating contributions and the relationship between the mutual-beating and the detection mode can be shown by a special optical system with a threedimentional scattering model composed of two fwo-dimentional models. They are varied with the expansion and the construction of the coherence volume. The experimental results show that the coherence broadening reaches its minimum value when the coherence volume and the illuminated volume are of the same magnitude.

A numerical treatment for determining the particle velocity and trajectory in a two-phase flows (the Fluctuation-Spectrum-Random-Trajectory Model ) is described herein and this model is proposed to account for the turbulent diffusion of the particles. It is tested for the flow of a turbulent axisymmetric gaseous jet ladn with spherical solid particles of non-uniform size and the predictions are compared with the data of Levy et al. The predictions of both phase velocity and gas-phase flucfuation...

A numerical treatment for determining the particle velocity and trajectory in a two-phase flows (the Fluctuation-Spectrum-Random-Trajectory Model ) is described herein and this model is proposed to account for the turbulent diffusion of the particles. It is tested for the flow of a turbulent axisymmetric gaseous jet ladn with spherical solid particles of non-uniform size and the predictions are compared with the data of Levy et al. The predictions of both phase velocity and gas-phase flucfuation velocity and experimental data is good agreement.