scholarly journals Thermal satellite images and boundary layer structures in desert marginal areas

2001 ◽  
Vol 28 (15) ◽  
pp. 2943-2946 ◽  
Author(s):  
Janet E. Nichol ◽  
A. T. Grove
Keyword(s):  
Boundary Layer ◽  
Satellite Images ◽  
Marginal Areas ◽  
Layer Structures

Finescale Dual-Doppler Analysis of Hurricane Boundary Layer Structures in Hurricane Frances (2004) at Landfall

2014 ◽  
Vol 142 (5) ◽  
pp. 1874-1891 ◽  
Author(s):  
Karen A. Kosiba ◽  
Joshua Wurman
Keyword(s):  
Boundary Layer ◽  
Three Dimensional ◽  
Transient Nature ◽  
Layer Structures ◽  
Characteristic Wavelength ◽  
Doppler Data ◽  
Mean Wind Speed ◽  
Average Flux ◽  
Hurricane Boundary Layer ◽  
The Right

Abstract Two Doppler on Wheels (DOW) mobile radars collected fine-spatial-scale dual-Doppler data in the right-front quadrant and eye of Hurricane Frances (2004) as it made landfall near Stuart, Florida. A 5.7-km dual-Doppler baseline established a dual-Doppler domain south and east of Fort Pierce, Florida, encompassing a 5.5 km × 5.5 km horizontal area, with a grid spacing of 20 m, allowing for the resolution of subkilometer-scale horizontal structures and associated kinematics. Three-dimensional vector wind analyses of the boundary layer revealed the presence of linear coherent structures with a characteristic wavelength of 400–500 m near the surface that increased in size and became more cellular in shape with increasing height. Average horizontal perturbation winds were proportional to average total horizontal winds. Within the eye of the hurricane, the features lost linear coherency despite a high mean wind speed, possibly due to changes in stability. A slight decrease in the characteristic wavelength of boundary layer structures was documented as the winds cross the barrier islands east of Fort Pierce. Vertical flux of horizontal momentum caused by individual vortical structures was substantially higher than values employed in turbulence parameterization schemes, but the domain-wide average flux was substantially lower than that in individual structures, likely due to the transient nature of the most intense portions of the structures. Analysis of the turbulent kinetic energy (TKE) yielded values comparable to those reported in previous observational studies over the open ocean. However, there was substantial variability in TKE within the dual-Doppler domain, emphasizing the challenge in obtaining representative samples using non-3D measurements such as dropsondes.

Measurement of boundary layer structures in chocolate cooling process

2020 ◽  
Vol 2020 (0) ◽  
pp. OS05-12
Author(s):  
Kento YAMADA ◽  
Hyun Jin PARK ◽  
Yuji TASAKA ◽  
Yuichi MURAI
Keyword(s):  
Boundary Layer ◽  
Cooling Process ◽  
Layer Structures

scholarly journals Supercapillary Architecture‐Activated Two‐Phase Boundary Layer Structures for Highly Stable and Efficient Flow Boiling Heat Transfer

2019 ◽  
Vol 32 (2) ◽  
pp. 1905117 ◽  
Author(s):  
Wenming Li ◽  
Zuankai Wang ◽  
Fanghao Yang ◽  
Tamanna Alam ◽  
Mengnan Jiang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Phase Boundary ◽  
Boiling Heat Transfer ◽  
Flow Boiling ◽  
Two Phase ◽  
Layer Structures ◽  
Flow Boiling Heat Transfer

scholarly journals Observation of a Severe Wind Case Caused by Gust Front and Its Boundary Layer Structures Characteristics

2018 ◽  
Vol 53 ◽  
pp. 03010
Author(s):  
Changyi Xu ◽  
Yan Wang
Keyword(s):  
Boundary Layer ◽  
Doppler Radar ◽  
Main Body ◽  
Observation Data ◽  
High Wind ◽  
Layer Structures ◽  
Wind Profiler Radar ◽  
Outflow Boundary ◽  
Wind Intensity ◽  
Gust Front

Based on Doppler radar 3D-composited reflectivity, wind profiler radar, boundary layer Tianjin tower of 255m as well as intensified automatic surface observation data, the evolution of the boundary layer associated with two successive gust front processes in the evening of 10 June 2016 and the intensity of the related disastrous surface high wind were analyzed. The results shown as follows: (1) To the same storm cell, the wind intensity caused by the outflow boundary in the main body was stronger than the wind caused by the gust front. The intensity of the disastrous high wind was related to the maximum descending velocity in the boundary layer and the associated height. The stronger the maximum descending velocity and the lower the level, the stronger the disastrous high wind was. (2) The tower data indicated, as the approaching of the gust front, convergence fluctuations first emerged at low(20m) and middle(120m) levels of the tower, leading the emergence of disastrous high wind by 8 minutes. When the gust front passed over, the maximum variations of cooling and the wind velocity were in pace with each other.

Laminar and Transitional Boundary Layer Structures in Accelerating Flow With Heat Transfer

1986 ◽  
Vol 108 (1) ◽  
pp. 116-123 ◽  
Author(s):  
K. Rued ◽  
S. Wittig
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Gas Turbine ◽  
Turbine Blades ◽  
Pressure Gradients ◽  
Transfer Coefficients ◽  
Gas Turbine Blades ◽  
Heat Transfer Coefficients ◽  
Layer Structures ◽  
Flow Heat

The accurate prediction of heat transfer coefficients on cooled gas turbine blades requires consideration of various influence parameters. The present study continues previous work with special efforts to determine the separate effects of each of several parameters important in turbine flow. Heat transfer and boundary layer measurements were performed along a cooled flat plate with various freestream turbulence levels (Tu = 1.6−11 percent), pressure gradients (k = 0−6 × 10−6), and cooling intensities (Tw/T∞ = 1.0−0.53). Whereas the majority of previously available results were obtained from adiabatic or only slightly heated surfaces, the present study is directed mainly toward application on highly cooled surfaces as found in gas turbine engines.

scholarly journals ANÁLISE MULTITEMPORAL DO USO E COBERTURA DO MANANCIAL ALAGADOS E DE SEU ENTORNO NA REGIÃO DE PONTA GROSSA-PR

2013 ◽  
Vol 35 (1) ◽  
pp. 24
Author(s):  
Paulo Costa de Oliveira Filho ◽  
Charles Andrey da Silva ◽  
Kelly Geronazzo Martins
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Water Surface ◽  
Satellite Images ◽  
Agricultural Practices ◽  
Degradation Process ◽  
Image Method ◽  
Marginal Areas ◽  
High Sedimentation

This study aimed the multitemporal analysis of land use and coverage of the water supply, Alagados and its surroundings (1 km range) in Ponta Grossa city over ten years (from 2001 to 2011). Especially attention was laid on the marginal areas (100 m range) of the permanentpreservation areas (PPA). As the major water suply source of Ponta Grossa city, deterioration of water quality of Alagados is threatened bythe misuse and disorderly occupation of its surroundings .We used satellite images of medium spatial resolution (30 meters) and the objectoriented image method preceded by the image segmentation as the classification techniques. The results showed that there was a significantreduction in the surface of the water surface in 13.43% (88.15 ha) in the period 2001 to 2011, which shows a high sedimentation processoccurred in certain areas of the reservoir. Changes were also detected in the PPA range domain (100 meters) surrounding the reservoir,confirming a degradation process due mainly to the increase buildings occupations and agricultural practices.

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