Integrating the energy flux method of shallow‐water reverberation with physics‐based seabed scattering models.

2011 ◽  
Vol 129 (4) ◽  
pp. 2631-2631 ◽  
Author(s):  
Ji‐Xun Zhou ◽  
Xue‐Zhen Zhang ◽  
Lin Wan ◽  
Zhaohui Peng ◽  
Zhenglin Li ◽  
...  
Keyword(s):  
Shallow Water ◽  
Energy Flux ◽  
Flux Method

New energy flux method for inspection of contact layer reticles

2002 ◽  
Author(s):  
William W. Volk ◽  
Hector I. Garcia ◽  
Charika Becker ◽  
George Chen ◽  
Sterling G. Watson
Keyword(s):  
Energy Flux ◽  
Contact Layer ◽  
Flux Method ◽  
New Energy

scholarly journals Two methods for estimating limits to large-scale wind power generation

2015 ◽  
Vol 112 (36) ◽  
pp. 11169-11174 ◽  
Author(s):  
Lee M. Miller ◽  
Nathaniel A. Brunsell ◽  
David B. Mechem ◽  
Fabian Gans ◽  
Andrew J. Monaghan ◽  
...  
Keyword(s):  
Power Generation ◽  
Kinetic Energy ◽  
Wind Power ◽  
Energy Flux ◽  
Wind Turbines ◽  
Large Scale ◽  
Wind Farms ◽  
Wind Power Generation ◽  
Flux Method ◽  
Free Atmosphere

Wind turbines remove kinetic energy from the atmospheric flow, which reduces wind speeds and limits generation rates of large wind farms. These interactions can be approximated using a vertical kinetic energy (VKE) flux method, which predicts that the maximum power generation potential is 26% of the instantaneous downward transport of kinetic energy using the preturbine climatology. We compare the energy flux method to the Weather Research and Forecasting (WRF) regional atmospheric model equipped with a wind turbine parameterization over a 105 km2 region in the central United States. The WRF simulations yield a maximum generation of 1.1 We⋅m−2, whereas the VKE method predicts the time series while underestimating the maximum generation rate by about 50%. Because VKE derives the generation limit from the preturbine climatology, potential changes in the vertical kinetic energy flux from the free atmosphere are not considered. Such changes are important at night when WRF estimates are about twice the VKE value because wind turbines interact with the decoupled nocturnal low-level jet in this region. Daytime estimates agree better to 20% because the wind turbines induce comparatively small changes to the downward kinetic energy flux. This combination of downward transport limits and wind speed reductions explains why large-scale wind power generation in windy regions is limited to about 1 We⋅m−2, with VKE capturing this combination in a comparatively simple way.

scholarly journals The decay of cyclonic eddies by Rossby wave radiation

1998 ◽  
Vol 361 ◽  
pp. 237-252 ◽  
Author(s):  
N. ROBB McDONALD
Keyword(s):  
Shallow Water ◽  
Explicit Expression ◽  
Energy Flux ◽  
Rossby Wave ◽  
Potential Vorticity ◽  
Phase Speed ◽  
Wave Radiation ◽  
Conservation Of Energy ◽  
Radiation Induced ◽  
General Method

It is argued that because shallow water cyclones on a β-plane drift westward at a speed equal to an available Rossby wave phase speed, they must radiate energy and cannot, therefore, be steady. The form of the Rossby wave wake accompanying a quasi-steady cyclone is calculated and the energy flux in the radiated waves determined. Further, an explicit expression for the radiation-induced northward drift of the cyclone is obtained. A general method for determining the effects of the radiation on the radius and amplitude of the vortex based on conservation of energy and potential vorticity is given. An example calculation for a cyclone with a ‘top-hat’ profile is presented, demonstrating that the primary effect of the radiation is to decrease the radius of the vortex. The dimensional timescale associated with the decay of oceanic vortices is of the order of several months to a year.

A NEW ENERGY-FLUX MODEL OF WAVEGUIDE REVERBERATION BASED ON PERTURBATION THEORY

2010 ◽  
Vol 18 (03) ◽  
pp. 209-225 ◽  
Author(s):  
J. R. WU ◽  
E. C. SHANG ◽  
T. F. GAO
Keyword(s):  
Perturbation Theory ◽  
Shallow Water ◽  
Energy Flux ◽  
Environmental Parameters ◽  
Water Area ◽  
Full Wave ◽  
Shallow Water Area ◽  
New Energy ◽  
Flux Model ◽  
Filtering Approach

The modal shallow water reverberation theory and the energy-flux shallow water reverberation theory were combined to get a new energy-flux model of waveguide reverberation based on Perturbation theory. There are only three environmental parameters (P, Q, μ) in the new reverberation model. It has clear physical picture and it is satisfied the waveguide constraint without any adjustable parameters. The new energy-flux reverberation model was compared with the modal reverberation model (full-wave reverberation model). The results show that the new model can explain the shallow water reverberation in most cases. It is shown that the contributions of parameter P and Q are mutual compensated (coupled) for a fixed reverberation data, therefore it is hard to extract both of them simultaneously. Finally, parameters P and μ at different frequencies were extracted from the reverberation data of "Qingdao-2005 experiment" in Yellow sea shallow-water area where the parameter Q has been extracted from mode filtering approach previously.

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