scholarly journals Wind speed-up in the Dover Straits with the Met Office New Dynamics Model

2003 ◽  
Vol 10 (3) ◽  
pp. 229-237 ◽  
Author(s):  
Rachel Anne Capon
Keyword(s):  
Wind Speed ◽  
Dynamics Model ◽  
Speed Up

scholarly journals 2.5D Flexible Wind Sensor Using Differential Plate Capacitors

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3101
Author(s):  
Yu Wan ◽  
Zhenxiang Yi
Keyword(s):  
Wind Speed ◽  
Wind Direction ◽  
Parallel Plate ◽  
Electrode Array ◽  
Copper Electrode ◽  
Windward Side ◽  
Leeward Side ◽  
Electrode Layer ◽  
Young’S Moduli ◽  
Speed Up

In this paper, a novel 2.5-dimensional (2.5D) flexible wind sensor is proposed based on four differential plate capacitors. This design consists of a windward pillar, two electrode layers, and a support layer, which are all made of polydimethylsiloxane (PDMS) with different Young’s moduli. A 2 mm × 2 mm copper electrode array is located on each electrode layer, forming four parallel plate capacitors as the sensitive elements. The wind in the xy-plane tilts the windward pillar, decreasing two capacitances on the windward side and increasing two capacitances on the leeward side. The wind in the z-axis depresses the windward pillar, resulting in an increase of all four capacitances. Experiments demonstrate that this sensor can measure the wind speed up to 23.9 m/s and the wind direction over the full 360° range of the xy-plane. The sensitivities of wind speed are close to 4 fF·m−1·s and 3 fF·m−1·s in the xy-plane and z-axis, respectively.

SIMPLE APPROXIMATIONS FOR WIND SPEED-UP OVER HILLS

1988 ◽  
pp. 117-127
Author(s):  
D.R. Lemelin ◽  
D. Surry ◽  
A.G. Davenport
Keyword(s):  
Wind Speed ◽  
Speed Up

Test and Analysis on the Thermal Environment of Island Subway Platform in Frosty Area

2013 ◽  
Vol 353-356 ◽  
pp. 3025-3028
Author(s):  
Pei Hong Zhang ◽  
Lei Xin Yu ◽  
Jian Wang
Keyword(s):  
Wind Speed ◽  
Thermal Environment ◽  
Field Measurements ◽  
Maximum Wind Speed ◽  
Subway Station ◽  
Test Results ◽  
Maximum Wind ◽  
Average Temperature ◽  
Speed Up ◽  
Full Height

in order to study the piston wind and its effect on the thermal environment and velocity field in island subway station platform with full-height non-enclosed screen doors, a number of field measurements were taken at the platform of century station of metro line 2 in Shenyang from Oct. 2012 to Mar. 2013. The test results show that the full-height non-enclosed screen doors enhances the heat transfer between the platform and the tunnel, the effect of piston wind increases the average temperature of platform by 0.7°C-1.4°C. Meanwhile, the full-height non-enclosed screen doors prevent the piston wind from entering into the platform effectively. The wind speed of the platform fluctuates between 0.25~0.52m/s when no train enters or leaves the platform, increasing slightly under the effect of the outdoor wind velocity. When one-way train goes into and out of the site, the maximum wind speed reaches up to 2.2m/s at the working area of platform. While, the wind speed of the stair section shows cyclical shocks between 1.2m/s ~ 1.7m/s with the amplitude attenuates gradually.The two-way train caused the the maximum wind speed up to 2m/s with the duration of 220s.

scholarly journals Surface flow modification of aerofoils for automotive racing car applications

2020 ◽  
Vol 34 (14n16) ◽  
pp. 2040096
Author(s):  
Richard Allarton ◽  
Jun Yao ◽  
Tyler Clifford ◽  
Benjamin Hitchborn ◽  
Liam J Parker ◽  
...  
Keyword(s):  
Wind Speed ◽  
Leading Edge ◽  
Surface Flow ◽  
Golf Ball ◽  
Flow Modification ◽  
Subsonic Wind Tunnel ◽  
Sport Industry ◽  
Speed Up ◽  
Computational Fluid Dynamics Cfd ◽  
Drag Ratio

An aerofoil commonly used in aerospace engineering to produce lift is also employed in the motor sport industry to produce downforce for improving traction during cornering. This paper investigates aerofoil surface modification through ‘golf ball dimpling’, used to reduce flow separation behind a golf ball. The studies of other researchers have shown that this type of design can have a positive effect on improving aerofoil performance. However, no optimization information of dimple sizing is given in literature. Therefore, three types of dimpling sized at 5, 10 and 15 mm are applied to the surface of a NACA 6615 wing at 25% chord length from the leading edge in this study using Computational Fluid Dynamics (CFD) as an initial design process. Then a physical model, made through 3D printing additive manufacturing (AM), is tested at angles of attack (AoA) ranging from [Formula: see text] to [Formula: see text] and wind speed up to 30 m/s in a subsonic wind tunnel. Experimental and CFD results show that the smallest dimple size provides the most significant increase on lift to drag ratio at high AoA above [Formula: see text]. This ratio increases further with the wind speed, indicating that a high AoA wing favors down force to improve drag reduction performance.

Research on the Dynamic Model and the Characteristics of Brown Rice Humidifier Ventilation Countercurrent Moisture Conditioning

2013 ◽  
Vol 373-375 ◽  
pp. 2156-2160
Author(s):  
Song Hua Yang ◽  
Yan Zhong Men
Keyword(s):  
Surface Roughness ◽  
Energy Consumption ◽  
Wind Speed ◽  
Moisture Content ◽  
Thin Layer ◽  
Air Temperature ◽  
Brown Rice ◽  
Simulation Method ◽  
Heat Consumption ◽  
Dynamics Model

The safety storage of rice or brown rice moisture content is below 14% ,hardness and brittleness is larger to low moisture content of brown rice, the crack in the manufacturing process of milling rice and broken rice rate is higher, milling processing energy consumption to increase, and the rice surface roughness is low .In this paper, using mathematical simulation method based on the theory of the humidifying, thin layer of humidifying dynamics model is established, and brown rice humidification conditioning properties are studied. Results show that the unit heat consumption is reduced with the increase of air temperature,humidifying rate increases, the bread machine temperature linearly increases; With the increase of wind speed, unit heat consumption increases, humidifying rate increased.

scholarly journals Modeling Turbulent Flow in an Urban Central Business District

2007 ◽  
Vol 46 (12) ◽  
pp. 2147-2164 ◽  
Author(s):  
Donald A. Burrows ◽  
Eric A. Hendricks ◽  
Steve R. Diehl ◽  
Robert Keith
Keyword(s):  
Wind Speed ◽  
Central Business District ◽  
Oklahoma City ◽  
Dynamics Model ◽  
Near Surface ◽  
Computational Fluid Dynamics Model ◽  
Sonic Anemometers ◽  
Turbulent Airflow ◽  
Joint Urban 2003 Experiment ◽  
Business District

Abstract The Realistic Urban Spread and Transport of Intrusive Contaminants (RUSTIC) model has been developed as a simplified computational fluid dynamics model with a k–ω turbulence model to be used to provide moderately fast simulations of turbulent airflow in an urban environment. RUSTIC simulations were compared with wind tunnel measurements to refine and “calibrate” the parameters for the k–ω model. RUSTIC simulations were then run and compared with data from five different periods during the Joint Urban 2003 experiment. Predictions from RUSTIC were compared with data from 33 near-surface sonic anemometers as well as 8 sonic anemometers on a 90-m tower and a sodar wind profiler located in the Oklahoma City, Oklahoma, central business district. The data were subdivided into daytime and nighttime datasets and then the daytime data were further subdivided into exposed and sheltered sonic anemometers. While there was little difference between day and night for wind speed and direction comparisons, there was considerable difference for the turbulence kinetic energy (TKE) comparisons. In the nighttime cases, RUSTIC overpredicted the TKE but without any correlation between model and observations. On the other hand, for the daytime cases, RUSTIC underpredicted the TKE values and correlated well with the observations. RUSTIC predicted both winds and TKE much better for the exposed sonic anemometers than for the sheltered ones. For the 90-m tower location downwind of the central business district, RUSTIC predicted the vertical profile of wind speed and direction very closely but underestimated the TKE.

scholarly journals Wind Speed Effects on the Quantity of Xanthomonas citri subsp. citri Dispersed Downwind from Canopies of Grapefruit Trees Infected with Citrus Canker

Plant Disease ◽  
2010 ◽  
Vol 94 (6) ◽  
pp. 725-736 ◽  
Author(s):  
C. H. Bock ◽  
J. H. Graham ◽  
T. R. Gottwald ◽  
A. Z. Cook ◽  
P. E. Parker
Keyword(s):  
Wind Speed ◽  
Ground Level ◽  
Citrus Canker ◽  
Disease Spread ◽  
Xanthomonas Citri ◽  
Wind Speeds ◽  
Speed Up ◽  
The Mean ◽  
Rain Events ◽  
The Relationship

The epidemic of citrus canker (Xanthomonas citri subsp. citri) in Florida continues to expand since termination of the eradication program in 2006. Storms are known to be associated with disease spread, but little information exists on the interaction of fundamental physical and biological processes involved in dispersal of this bacterium. To investigate the role of wind speed in dispersal, wind/rain events were simulated using a fan to generate wind up to 19 m·s-1 and spray nozzles to simulate rain. Funnels at ground level and panels at 1.3 m height and distances up to 5 m downwind collected wind-driven splash. Greater wind speeds consistently dispersed more bacteria, measured by concentration (colony forming units [CFU] ml-1) or number sampled (bacteria flux density [BFD] = bacteria cm-2 min-1), from the canopy in the splash. The CFU ml-1 of X. citri subsp. citri collected by panels 1 m downwind at the highest wind speed was up to 41-fold greater than that collected at the lowest wind speed. BFD at the highest wind speed was up to 884-fold higher than that collected at the lowest wind speed. Both panels at distances >1 m and funnels at distances >0 m collected many-fold more X. citri subsp. citri at higher wind speeds compared to no wind (up to 1.4 × 103-fold greater CFU ml-1 and 1.8 × 105-fold the BFD). The resulting relationship between wind speed up to 19 m·s-1 and the mean CFU ml-1 collected by panel collectors downwind was linear and highly significant. Likewise, the mean CFU ml-1 collected from the funnel collectors had a linear relationship with wind speed. The relationship between wind speed and BFD collected by panels was generally similar to that described for CFU ml-1 of X. citri subsp. citri collected. However, BFD collected by funnels was too inconsistent to determine a meaningful relationship with increasing wind speed. The quantity of bacteria collected by panels declined with distance, and the relationship was described by an inverse power model (R2 = 0.94 to 1.00). At higher wind speeds, more bacteria were dispersed to all distances. Windborne inoculum in splash in subtropical wet environments is likely to be epidemiologically significant, as both rain intensity and high wind speed can interact to provide conditions conducive for dispersing large quantities of bacteria from canker-infected citrus trees. Disease and crop management aimed at reducing sources of inoculum and wind speeds in a grove should help minimize disease spread by windborne inoculum.

scholarly journals Study on the Influence of Slope on Pollutant Diffusion Characteristics during Tunnel Construction Period

2019 ◽  
Vol 118 ◽  
pp. 04005
Author(s):  
Zubin Ai ◽  
Zhongqiang Song ◽  
Fan Chen ◽  
Song Yang ◽  
Zhensheng Cao ◽  
...  
Keyword(s):  
Wind Speed ◽  
Traffic Safety ◽  
Reduction Rate ◽  
Tunnel Construction ◽  
Tunnel Length ◽  
Construction Period ◽  
Diffusion Characteristics ◽  
Speed Up ◽  
The Impact ◽  
Dust Reduction

. The relative elevation of the beginning and end of the Jianyuan Expressway exceed 1000m. In order to overcome the impact of the large slope on traffic safety, a spiral tunnel was designed in the middle of the expressway. The tunnel length is 3970m and the radius is 710~730m with its slope being up to 2.08%. The occurrence of large slope has a great impact on ventilation and smoke during tunnel construction, but little research has been done before. In this paper, numerical simulation and field test were used to study the effect of slope on the diffusion characteristics of pollutants. It was found that as the slope increased, the wind speed and CO dilution rate also increased. However, the dust dilution characteristics were different. Especially in the case of the downward tunnel, the effect of wind speed on the sedimentation rate of dust was minimal. Simply increasing the wind speed cannot speed up the dust reduction rate.

scholarly journals Effect of Wind Speed up by Seawall on a Wind Turbine

2013 ◽  
Vol 33 (3) ◽  
pp. 1-8 ◽  
Author(s):  
Young-Cheol Ha ◽  
Bong-Hee Lee ◽  
Hyun-Goo Kim
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Speed Up

A Discussion on recent research in air pollution - The distribution of surface concentrations of sulphur dioxide emitted from tall chimneys

1969 ◽  
Vol 265 (1161) ◽  
pp. 245-259 ◽  
Keyword(s):  
Wind Speed ◽  
Sulphur Dioxide ◽  
Concentration Distribution ◽  
Mean Values ◽  
Average Surface ◽  
Speed Up ◽  
Strong Winds ◽  
The Individual ◽  
Axial Concentration ◽  
Marked Dependence

The observed mean values of the maximum hourly average surface sulphur dioxide concentration from generating station plumes (stack height 100 m and above) exhibit a marked dependence on wind speed. At night the lowest concentrations occur in light winds, and the concentration increases almost linearly with wind speed up to speeds of 14 m s-1 at stack top. In the daytime the lowest concentrations occur at about 4 m s-1 with a secondary maximum in light winds. The distributions of the individual hourly average values in both light and strong winds are discussed and some practical methods for predicting these distributions are suggested. The variations with distance from the source of the axial concentration, crosswind standard deviation and the concentration integrated across wind are discussed in terms of departures from the isotropic gaussian concentration distribution.

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