The impact of ocean waves on spray stress and surface drag coefficient

2019 ◽  
Vol 29 (2) ◽  
pp. 523-535
Author(s):  
Zhanhong Wan ◽  
Luping Li ◽  
Zhigen Wu ◽  
Jiawang Chen ◽  
Xiuyang Lü
Keyword(s):  
Drag Coefficient ◽  
Momentum Flux ◽  
Sea Surface ◽  
Sea Spray ◽  
Wave Age ◽  
Surface Drag ◽  
Content Type ◽  
Flux Formula ◽  
Hurricane Prediction ◽  
Windsea Reynolds Number

Purpose The behaviors of sea surface drag coefficient should be well understood for an accurate hurricane prediction. The speed of wind has been applied to characterize the spray production; however, this could result in inaccurate spray productions compared to the experimental or field data if the influence of wave state is not considered. This paper aims to integrate a new sea spray generation function, described by windsea Reynolds number, into the spray momentum flux formula to calculate the spray momentum. Design/methodology/approach On the basis of this spray momentum, this study proposes the new formulas of spray stress and drag coefficient when the wind speed is high. Findings Results of the revised formulas show that wave status had significant effects on the spray stress and sea surface drag coefficient. Also, wave age was found to be an important parameter that affects the drag coefficient. The drag coefficient decreased with the increasing wave age. Comparison between this study’s theoretical and observation values of drag coefficient shows that the study results are close to the measured values. Research limitations/implications The research findings can enhance the understanding of the behaviors of sea surface drag for an accurate hurricane prediction. Originality/value A new sea spray generation function, described by windsea Reynolds number, is integrated into the spray momentum flux formula to calculate the spray momentum. On the basis of this spray momentum, this study proposes the new formulas of spray stress and drag coefficient when the wind speed is high.

scholarly journals Relationship between Sea Surface Drag Coefficient and Wave State

2021 ◽  
Vol 9 (11) ◽  
pp. 1248
Author(s):  
Jian Shi ◽  
Zhihao Feng ◽  
Yuan Sun ◽  
Xueyan Zhang ◽  
Wenjing Zhang ◽  
...  
Keyword(s):  
Drag Coefficient ◽  
Momentum Flux ◽  
Sea Surface ◽  
Sea Spray ◽  
Wave Age ◽  
High Wind ◽  
Surface Drag ◽  
Wave State ◽  
Wind Speeds ◽  
Strong Winds

The sea surface drag coefficient plays an important role in momentum transmission between the atmosphere and the ocean, which is affected by ocean waves. The total air–sea momentum flux consists of effective momentum flux and sea spray momentum flux. Sea spray momentum flux involves sea surface drag, which is largely affected by the ocean wave state. Under strong winds, the sea surface drag coefficient (CD) does not increase linearly with the increasing wind speed, namely, the increase of CD is inhibited by strong winds. In this study, a sea surface drag coefficient is constructed that can be applied to the calculation of the air–sea momentum flux under high wind speed. The sea surface drag coefficient also considers the influence of wave state and sea spray droplets generated by wave breaking. Specially, the wave-dependent sea spray generation function is employed to calculate sea spray momentum flux. This facilitates the analysis not only on the sensitivity of the sea spray momentum flux to wave age, but also on the effect of wave state on the effective CD (CD, eff) under strong winds. Our results indicate that wave age plays an important role in determining CD. When the wave age is >0.4, CD decreases with the wave age. However, when the wave age is ≤0.4, CD increases with the wave age at low and moderate wind speeds but tends to decrease with the wave age at high wind speeds.

scholarly journals Experimental Study of High Wind Sea Surface Drag Coefficient

2015 ◽  
Author(s):  
I.A. Repina ◽  
A.Yu. Artamonov ◽  
M.I. Varentsov ◽  
A.V. Kozyrev ◽  
◽  
...  
Keyword(s):  
Experimental Study ◽  
Drag Coefficient ◽  
Sea Surface ◽  
High Wind ◽  
Surface Drag ◽  
Wind Sea

scholarly journals On the Linear Parameterization of Drag Coefficient over Sea Surface

2004 ◽  
Vol 34 (12) ◽  
pp. 2847-2851 ◽  
Author(s):  
Changlong Guan ◽  
Lian Xie
Keyword(s):  
Wind Speed ◽  
Drag Coefficient ◽  
Linear Function ◽  
Sea Surface ◽  
Wave Steepness ◽  
Wave Age ◽  
Age Dependent ◽  
Logarithmic Law ◽  
Linear Parameterization ◽  
Charnock Relation

Abstract Combining the logarithmic law with the Charnock relation yields a drag coefficient that is a function of wind speed with the Charnock coefficient as a parameter. It is found that the function is nearly linear within the typically measured range of the drag coefficient. The slope of the linear function is dominated by the Charnock coefficient. When the Charnock relation is extended to a wave age–dependent function, the drag coefficient remains a near-linear function of wind speed after invoking the 3/2 power law. The slope of the linear function is dominated by wave steepness.

Dependence of sea surface drag coefficient on wind-wave parameters

2011 ◽  
Vol 30 (2) ◽  
pp. 14-24 ◽  
Author(s):  
Jian Shi ◽  
Zhong Zhong ◽  
Ruijie Li ◽  
Yan Li ◽  
Wenyu Sha
Keyword(s):  
Drag Coefficient ◽  
Wind Wave ◽  
Sea Surface ◽  
Surface Drag ◽  
Wave Parameters

scholarly journals Experimental Study of High Wind Sea Surface Drag Coefficient

2015 ◽  
Author(s):  
I.A. Repina ◽  
A.Yu. Artamonov ◽  
M.I. Varentsov ◽  
A.V. Kozyrev ◽  
◽  
...  
Keyword(s):  
Experimental Study ◽  
Drag Coefficient ◽  
Sea Surface ◽  
High Wind ◽  
Surface Drag ◽  
Wind Sea

scholarly journals Parameterization of Sea Surface Drag Coefficient for All Wind Regimes Using 11 Aircraft Eddy-Covariance Measurement Databases

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1485
Author(s):  
Zhiqiu Gao ◽  
Shaohui Zhou ◽  
Jianbin Zhang ◽  
Zhihua Zeng ◽  
Xueyan Bi
Keyword(s):  
Wind Speed ◽  
Transfer Coefficient ◽  
Drag Coefficient ◽  
Sea Surface ◽  
Turbulent Heat Transfer ◽  
Horizontal Wind ◽  
Turbulent Heat ◽  
Mean Flow ◽  
Surface Drag ◽  
Horizontal Wind Speed

The drag coefficient is essential for calculating the aerodynamic friction between air and sea. In this study, we regress a set of relationships between the drag coefficient and the wind speed for different wind ranges using an observational dataset that consists of 5941 estimates of the mean flow and fluxes from 11 aircraft turbulent measurements over the sea surface. Results show that: (1) the drag coefficient is a power function of wind speed over smooth sea surface when it is no greater than 4.5 ms−1, and the drag coefficient decreases with the increase of wind speed; and (2) for rough sea surface, when the wind speed is greater than 4.5 ms−1 and less than or equal to 10.5 ms−1, the drag coefficient increases linearly with the increase of horizontal wind speed; when the wind speed is greater than 10.5 ms−1 and less than or equal to 33.5 ms−1, the drag coefficient changes parabolically with the increase of wind speed; when the wind speed is greater than 33.5 ms−1, the drag coefficient is constant. Additionally, regressed from drag coefficient, the saturated wind speed threshold is 23 ms−1. Parameterizations of turbulent heat transfer coefficient (Ch) and water vapor transfer coefficient (Ce) are also investigated.

Laboratory investigation of air-sea momentum transfer under severe wind conditions

2020 ◽  
Author(s):  
Maksim Vdovin ◽  
Georgy Baydakov ◽  
Daniil Sergeev ◽  
Yuliya Troitskaya
Keyword(s):  
Wind Speed ◽  
Data Processing ◽  
Drag Coefficient ◽  
Financial Support ◽  
Water Surface ◽  
Wind Wave ◽  
Aerodynamic Resistance ◽  
Sea Surface ◽  
Surface Drag ◽  
Wave Flume

<p>Wind-wave interaction at extreme wind speed is of special interest now in connection with the problem of explanation of the sea surface drag saturation at the wind speed exceeding 30 m/s. Now it is established that at hurricane wind speed the sea surface drag coefficient is significantly reduced in comparison with the parameterization obtained at moderate to strong wind conditions.</p><p>The subject of this work is investigation of aerodynamic resistance of the waved water surface under severe wind conditions (up to U10 ≈ 50 m/s). Laboratory experiments were carried out at the new high-speed wind-wave flume in the Large Thermally Stratified Tank (at the Institute of Applied Physics, Russia) built in 2019. The main difference between the new wind-wave flume and the old one is the absence of a pressure gradient along the main axis of the new flume. Aerodynamic resistance of the water surface was measured by the profile method with Pitot tube. A method for data processing taking into account the self-similarity of the air flow velocity profile in the aerodynamic tube was applied for retrieving wind friction velocity and surface drag coefficients. Simultaneously with the airflow velocity measurements, the wind-wave field parameters in the flume were investigated by system of wire gauges.</p><p>Analysis of the wind velocity profiles and wind-wave spectra showed tendency to decrease for surface drag coefficient for wind speed exceeding 25 m/s simultaneously with the mean square slope and significant wave height.</p><p><span>Acknowledgments</span> <br>This work was carried out with the financial support of the RFBR according to the research project 18-55-50005, 20-05-00322, 18-35-20068, 18-05-00265. Data processing was carried out with the financial support of Russian Science Foundation grant 19-17-00209.</p>

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