scholarly journals Potential and challenges of wind measurements using met-masts in complex topography for bridge design: Part II – Spectral flow characteristics

2021 ◽  
Vol 211 ◽  
pp. 104585
Author(s):  
Zakari Midjiyawa ◽  
Etienne Cheynet ◽  
Joachim Reuder ◽  
Hálfdán Ágústsson ◽  
Trond Kvamsdal
Keyword(s):  
Flow Characteristics ◽  
Spectral Flow ◽  
Complex Topography ◽  
Bridge Design ◽  
Wind Measurements

scholarly journals Potential and challenges of wind measurements using met-masts in complex topography for bridge design: Part I – Integral flow characteristics

2021 ◽  
Vol 211 ◽  
pp. 104584
Author(s):  
Zakari Midjiyawa ◽  
Etienne Cheynet ◽  
Joachim Reuder ◽  
Hálfdán Ágústsson ◽  
Trond Kvamsdal
Keyword(s):  
Flow Characteristics ◽  
Complex Topography ◽  
Bridge Design ◽  
Wind Measurements

Analysis of Characteristics of Potential Mud-Rock Flow in Huyu Valley

2011 ◽  
Vol 295-297 ◽  
pp. 1777-1781
Author(s):  
Yi Qing Lv ◽  
Hong Fu Liu ◽  
Xue Qin Wen
Keyword(s):  
Debris Flow ◽  
Flow Characteristics ◽  
Natural Weathering ◽  
Geological Condition ◽  
Complex Topography ◽  
Human Engineering ◽  
Geological Processes

Taking potential debris flow in Huyu Valley as research object, the investigation of geological condition in Huyu Valley and different accompanied geological processes has been investigated such as complex topography, natural weathering and source of loose debris produced by the accumulation of human engineering activities, the role of uneven rainfall. With the analysis of potential debris flow characteristics of the Huyu Valley comprehensively, the results showes that the potential debris flow of the Huyu Valley already has satisfied conditions.

scholarly journals Local turbulent kinetic energy modelling based on Lagrangian stochastic approach in CFD and application to wind energy

2021 ◽  
Author(s):  
Kerlyns Martínez ◽  
Mireille Bossy ◽  
Jean-François Jabir
Keyword(s):  
Kinetic Energy ◽  
Wind Energy ◽  
Stochastic Model ◽  
Turbulent Kinetic Energy ◽  
Flow Characteristics ◽  
Direct Methods ◽  
Physical Parameters ◽  
Uncertainty Distribution ◽  
Deterministic Modelling ◽  
Wind Measurements

<p>In order to better integrate the underlying meteorological processes with the developing technologies within wind energy industry, acquiring relevant statistical information of air motion at a local place, and quantifying the subsequent uncertainty of involved parameters in the models, are fundamental tasks. Special emphasis should be made on the growing interest in energy production forecasting and modelling for wind energy developments that rises the issue of accounting for the uncertain nature of the local forecast. Taking this into consideration, we present the construction of an original stochastic model for the instantaneous turbulent kinetic energy at a given point of a flow, and we validate estimator methods on this model with observational data examples from annual historic of a 10 Hz anemometer wind measurements. <br>More precisely, starting from the viewpoint of Lagrangian modelling of the wind in the boundary layer, we establish a mathematical link between 3D+time computational fluid dynamics (CDF) models for turbulent near-wall flows and stochastic time series models by deriving a family of mean-field dynamics featuring the square norm of the turbulent velocity. Then, by approximating at equilibrium the characteristic nonlinear terms of the dynamics, we recover the so called Cox-Ingersoll-Ross stochastic model, which was previously suggested in the literature for modelling wind speed. Remarkably, our stochastic model for the instantaneous turbulent kinetic energy is parametrised by physical constants in CFD, which provides a more direct link between the stochastic nature of the underlying processes and the classical physics behind these phenomena. Nevertheless, these physical parameters may vary with the flow characteristics and situations, so we consider it relevant to adjust their values while constructing the forecasts. Such tuning of the physical parameters was previously proposed in the literature from a deterministic modelling context with RANS equations. We then propose a two-step procedure for the calibration of the parameters: a training stage where we construct a priori distribution for the parameter vector using direct methods and wind measurements, and a stage of refinement of the uncertainty distribution using Bayesian inference combined with Markov Chain Monte Carlo sample techniques. In particular, we show the accuracy of the calibration method and the performance of the calibrated model in predicting the wind distribution through the quantification of uncertainty.</p>

Acoustic Damping Analysis of Bias Flow Liners Based on Spectral Flow Characteristics

2013 ◽  
Author(s):  
Anita Schulz ◽  
Daniel Haufe ◽  
Andreas Fischer ◽  
Jürgen Czarske ◽  
Friedrich Bake ◽  
...  
Keyword(s):  
Flow Characteristics ◽  
Spectral Flow ◽  
Acoustic Damping ◽  
Bias Flow

Effect of hydrodynamic impact and cavitation on oil flow characteristics

2019 ◽  
pp. 46-50
Author(s):  
V.N. Petrov ◽  
◽  
F.M. Galimov ◽  
L.A. Akhmetzyanova ◽  
S.V. Petrov ◽  
...  
Keyword(s):  
Flow Characteristics ◽  
Hydrodynamic Impact ◽  
Oil Flow
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