Three-parameter model of shear turbulence

1978 ◽  
Vol 13 (3) ◽  
pp. 350-360 ◽  
Author(s):  
V. G. Lushchik ◽  
A. A. Pavel'ev ◽  
A. E. Yakubenko
Keyword(s):  
Shear Turbulence

Examination of diffusion modeling using zero-mean-shear turbulence

AIAA Journal ◽  
1998 ◽  
Vol 36 ◽  
pp. 929-935
Author(s):  
A. G. Straatman ◽  
G. D. Stubley ◽  
G. D. Raithby
Keyword(s):  
Diffusion Modeling ◽  
Shear Turbulence

Contrasting dynamic characteristics of shear turbulence and Langmuir circulation in the surface mixed layer

2015 ◽  
Vol 34 (5) ◽  
pp. 1-11 ◽  
Author(s):  
Guojing Li ◽  
Dongxiao Wang ◽  
Ju Chen ◽  
Jinglong Yao ◽  
Lili Zeng ◽  
...  
Keyword(s):  
Mixed Layer ◽  
Dynamic Characteristics ◽  
Surface Mixed Layer ◽  
Langmuir Circulation ◽  
Shear Turbulence

Transverse Distribution of the Streamwise Velocity for the Open-channel Flow With Floating Vegetated Islands

2021 ◽  
Author(s):  
Xuecheng Fu ◽  
Feifei Wang ◽  
Mengyang Liu ◽  
Wenxin Huai
Keyword(s):  
Channel Flow ◽  
Open Channel ◽  
Flow Characteristics ◽  
Open Channel Flow ◽  
Streamwise Velocity ◽  
Transport Efficiency ◽  
Transverse Distribution ◽  
Floating Vegetation ◽  
Shear Turbulence ◽  
Field Disturbance

Abstract Floating vegetation islands (FVIs) have been widely utilized in various river ecological restoration projects due to their ability to purify pollutants. FVIs float at the surface of shallow pools with their roots unanchored in the sediment. Biofilm formed by roots under islands filters nutrients and particles in the water flowing through it. Flow field disturbance will occur and transverse distribution of flow velocity will change due to the existence of FVIs. Transport efficiency of suspended solids, nutrients, and pollutants will also be altered. A modified analytical model that considers effects of boundary friction, drag force of vegetation, transverse shear turbulence, and secondary flow is established to predict transverse variation of depth-averaged streamwise velocity for the open-channel flow with FVIs using Shiono and Knight method. The simulation results with suitable boundary conditions successfully predicted lateral profile of the depth-averaged streamwise velocity compared with the experimental results of symmetrical and unsymmetrical arrangements of FVIs. Hence, the presented model can provide guidance for investigating flow characteristics of rivers with FVIs.

Effect of heat source on statistics and scaling in compressible homogeneous shear turbulence

2021 ◽  
Vol 33 (12) ◽  
pp. 125128
Author(s):  
Yuandong Chen ◽  
Xiaoning Wang ◽  
Zhou Jiang ◽  
Jianchun Wang
Keyword(s):  
Heat Source ◽  
Homogeneous Shear ◽  
Shear Turbulence

scholarly journals Impact of pitch angle fluctuations on airborne lidar forward sensing along the flight direction

2017 ◽  
Vol 10 (10) ◽  
pp. 3851-3864 ◽  
Author(s):  
Alexander Sergeevich Gurvich ◽  
Victor Alexeevich Kulikov
Keyword(s):  
Pitch Angle ◽  
Beam Steering ◽  
Airborne Lidar ◽  
Civil Aviation ◽  
Aerosol Layer ◽  
Flight Direction ◽  
Air Turbulence ◽  
Shear Turbulence ◽  
Geometrical Factors ◽  
Vertical Scales

Abstract. Airborne lidar forward sensing along the flight direction can serve for notification of clear air turbulence (CAT) and help to prevent injuries or fatal air accidents. The validation of this concept was presented in the framework of the DELICAT (DEmonstration of LIdar-based CAT detection) project. However, the strong variations in signal level, which were observed during the DELICAT measurements but not explained, sometimes indicated the need of a better understanding the observational errors due to geometrical factors. In this paper, we discuss possible error sources pertinent to this technique, related to fluctuations of the flight parameters, which may lead to strong signal variations caused by the random deviations of the sensing beam from the forward flight trajectory. We analyze the variations in backscattered lidar signal caused by fluctuations of the most important forward-sensing flight parameter, the pitch angle. The fluctuation values considered in the paper correspond to the error limits of the compensational gyro platform used in civil aviation. The part of the pitch angle fluctuations not compensated for by the beam-steering device in the presence of aerosol concentration variations can lead to noticeable signal variations that can be mistakenly attributed to wind shear, turbulence, or fast evolution of the aerosol layer. We formulate the criteria that allow the recognition of signal variations caused by pitch angle fluctuations. Influence of these fluctuations is shown to be stronger for aerosol variations on smaller vertical scales. An example of DELICAT observations indicating a noticeable pitch angle fluctuation impact is presented.

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