In this study,typhoon waves generated during three typhoons(Damrey(1210),Fung-wong(1416),and Chan-hom(1509))in the Yellow Sea and East China Sea were simulated in a simulating waves nearshore(SWAN)model,and the wind f...In this study,typhoon waves generated during three typhoons(Damrey(1210),Fung-wong(1416),and Chan-hom(1509))in the Yellow Sea and East China Sea were simulated in a simulating waves nearshore(SWAN)model,and the wind forcing was constructed by combining reanalyzed wind data with a Holland typhoon wind model.Various parameters,such as the Holland fitting parameter(B)and the maximum wind radius?,were investigated in sensitivity experiments in the Holland model that affect the wind field construction.Six different formulations were considered and the parameters determined by comparing the simulated wind results with in-situ wind measurements.The key factors affecting wave growth and dissipation processes from deep to shallow waters were studied,including wind input,whitecapping,and bottom friction.Comparison with in-situ wave measurements suggested that the KOMEN scheme(wind input exponential growth and whitecapping energy dissipation)and the JONSWAP scheme(dissipation of bottom friction)resulted in good reproduction of the significant wave height of typhoon waves.A preliminary analysis of the wave characteristics in terms of wind-sea and swell wave revealed that swell waves dominated with the distance of R to the eye of the typhoon,while wind-sea prevailed in the outer region up to six to eight times the R values despite a clear misalignment between wind and waves.The results support the hypothesis that nonlinear wave-wave interactions may play a key role in the formation of wave characteristics.展开更多
Investigated is the coupled response of a tension leg platform （TLP） for random waves. Inferred are the mass matrix, coupling stiffness matrix, damping matrix in the vibration differential equation and external load...Investigated is the coupled response of a tension leg platform （TLP） for random waves. Inferred are the mass matrix, coupling stiffness matrix, damping matrix in the vibration differential equation and external load of TLP in moving coordinating system. Infinitesimal method is applied to divide columns and pontoons into small parts. Time domain motion equation is solved by Runge-Kutta integration scheme. Jonswap spectrum is simulated in the random wave, current is simulated by linear interpolation, and NPD spectrum is applied as wind spectrum. The Monte Carlo method is used to simulate random waves and fluctuated wind. Coupling dynamic response, change of tendon tension and riser tension in different sea conditions are analyzed by power spectral density （PSD）. The influence of approach angle on dynamic response of TLP and tendon tension is compared.展开更多
The effects of waves on Surface Drag Coefficient （SDC） and surface mixing length were analyzed and discussed by carrying out three-dimensional current modeling for the Bohai Sea in the present work. A threedimension...The effects of waves on Surface Drag Coefficient （SDC） and surface mixing length were analyzed and discussed by carrying out three-dimensional current modeling for the Bohai Sea in the present work. A threedimensional coupled hydrodynamical-ecological model for regional and shelf seas （COHERENS） incorporating the influences of wave-current interactions was coupled with the third-generation wave model swan taking into account time-varying currents. The effects of waves on currents were included in the SDC, surface mixing length and bottom drag coefficient. Firstly, the formulations in Donelan were incorporated into the COHERENS to account for wave-dependent SDC. In order to compare simulation results for the wave-dependent SDC, the simulation for wind-dependent SDC was also carried out. Second, Wave-Induced Surface Mixing Length （described as WISML sometimes in this paper） was incorporated into the COHERENS. Four numerical experiments were conducted to discuss the effects of two kinds of wave processes. Generally, the values of time series of current velocity and water surface elevation given by the simulation with all of the three wave processes have a good agreement with observed data. The existence of WISML changes obviously current vertical profiles and the existence of the wave dependent SDC modifies the current field of both top and bottom layers with the wind-dependent SDC.展开更多
Due to the long-standing lack of understanding the role of wind waves on wind stress at moderate to high wind speeds,a high-frequency turbulence observation system is used in this study to obtain air-sea momentum flux...Due to the long-standing lack of understanding the role of wind waves on wind stress at moderate to high wind speeds,a high-frequency turbulence observation system is used in this study to obtain air-sea momentum flux data under pure wind wave conditions based on the tower-based marine meteorological observation platform in the southern Bohai Sea.Moreover,the modulation of wind waves on wind stress under wind speeds greater than 10 m s^(–1)is analyzed.The results indicated that the wind wave states caused by winds from the northwest and northeast are different under the influence of cold air,resulting in different wind stresses and drag coefficients.The wind stress increases with an increasing wind speed,reaching its maximum value when the northwest wind is nearly 20 m s^(–1),while the extreme value of the drag coefficient is basically the same when the northwest wind speed is the maximum and the northeast wind wave significant wave height is the maximum.The drag coefficient increases with an increasing wind speed within the range of 10–15 m s^(–1),reaching saturation at 15 m s^(–1).The critical wind speed is smaller than other observed results.Further analysis showed that wind-induced turbulent stress deviates from the observed values,and the degree of deviation depends on the wind speed and wave state,with a greater deviation caused by strong winds and waves.The wave-induced stress can correct the negative deviation between wind-induced turbulent stress and the observed value,and the drag coefficient calculated based on the modified wind stress tends to be close to the observed value overall.展开更多
Based on observations from buoys, it is found that the wave age is well correlated with the nondimensional wave height, and this correlation is best described by a 3/5-power law. This similarity law is valid in the ca...Based on observations from buoys, it is found that the wave age is well correlated with the nondimensional wave height, and this correlation is best described by a 3/5-power law. This similarity law is valid in the cases of wind waves as well as swells under natural sea states. On the basis of the 3/5-power law combined with the well-known 3/2-power law I it is shown that the wave-induced wind stress increases rapidly with wave age, indicating that the traditional observations or analytic techniques have only given the turbulent Reynolds stress induced by short wind waves, but excluded the long-wave-induced wind stress. The latter constitutes a small fraction to the total wind stress when the wave age is smaller than 1.0. The increase of sea-surface roughness with wave age can be attributed to wave breaking.展开更多
The article solves the problem of surface gravitational waves using the theory of tangential discontinuity between media: air-water. Using the improved equation of mass continuity and taking into account the atmospher...The article solves the problem of surface gravitational waves using the theory of tangential discontinuity between media: air-water. Using the improved equation of mass continuity and taking into account the atmosphere inhomogeneity in the gravitational field of the Earth, it is shown that during wave processes, these two media mutually influence each other, which explains the reason for the formation of a stormy condition over the ocean and the drop in atmospheric pressure before the storm. The mechanism of the formation of the “killer wave” has been established and thus the “greatest mystery of nature” has been solved. The scale of wind and tsunami wavelengths has been established.展开更多
Over the tropics, convection, wind shear （i.e., vertical and horizontal shear of wind and/or geostrophic adjustment comprising spontaneous imbalance in jet streams） and topography are the major sources for the gener...Over the tropics, convection, wind shear （i.e., vertical and horizontal shear of wind and/or geostrophic adjustment comprising spontaneous imbalance in jet streams） and topography are the major sources for the generation of gravity waves. During the summer monsoon season （June August） over the Indian subcontinent, convection and wind shear coexist. To determine the dominant source of gravity waves during monsoon season, an experiment was conducted using mesosphere-stratosphere-troposphere （MST） radar situated at Gadanki （13.5°N, 79.2°E）, a tropical observatory in the southern part of the Indian subcontinent. MST radar was operated continuously for 72 h to capture high-frequency gravity waves. During this time, a radiosonde was released every 6 h in addition to the regular launch （once daily to study low-frequency gravity waves） throughout the season. These two data sets were utilized effectively to characterize the jet stream and the associated gravity waves. Data available from collocated instruments along with satellite-based brightness temperature （TBB） data were utilized to characterize the convection in and around Gadanki. Despite the presence of two major sources of gravity wave generation （i.e., convection and wind shear） during the monsoon season, wind shear （both vertical shear and geostrophic adjustment） contributed the most to the generation of gravity waves on various scales.展开更多
Wave slamming is an important phenomenon due to its destructive power,and with the rapid development of offshore wind turbines,wave slamming on vertical cylinders has garnered lots of attention.However,the phenomenon ...Wave slamming is an important phenomenon due to its destructive power,and with the rapid development of offshore wind turbines,wave slamming on vertical cylinders has garnered lots of attention.However,the phenomenon of wave slamming on vertical cylinders is very complicated due to both the intrinsic complexity of breaking waves and that of slamming forces.The objective of this paper is to provide a general review of research related to this problem,including theoretical methods,experimental studies,numerical simulations,and full-scale measurements.Based on these approaches,the momentum theory/pressure impulse theory,spatial distribution characteristics of impacts to various breaking waves,wave generation methods,analysis methods for measured forces under structure response,scale effects in experiments,and in-situ measurements have been introduced and discussed.Results show that simplifications in existing models for wave impacting such as wave characteristics and structural response reduce its applicability and should be studied further both in theoretical,experimental and numerical researches.展开更多
In many areas around the world, wake surfing has been cited as one of the major causes of lakeshore erosion and turbidity. This paper quantifies the impact related to turbidity and erosion with the use of computationa...In many areas around the world, wake surfing has been cited as one of the major causes of lakeshore erosion and turbidity. This paper quantifies the impact related to turbidity and erosion with the use of computational fluid dynamics (CFD) of boat wakes in shallow water and the build-up of wind driven waves. The energy, type and direction of the boat’s wake are described quantitatively and a table for predicting wind driven waves over varying fetches, depth and wind speeds is provided. The CFD simulation shows that if a wake surf boat is operated 200 ft from shore and in at least 10 ft of water, the environmental impact is minimal.展开更多
Wind input parameterizations proposed by Jeffreys, Sverdrup and Munk, and Plant are analyzed. It is found by analogy that the similarity of integrals of the three wind input parameterizations exists. Wave breaking dis...Wind input parameterizations proposed by Jeffreys, Sverdrup and Munk, and Plant are analyzed. It is found by analogy that the similarity of integrals of the three wind input parameterizations exists. Wave breaking dissipation parameterizations proposed by Tsikunov, Hasselmann, and Phillips are also analyzed. Likewise it is found by analogy that the similarity of integrals of the three dissipation parameterizations exists. The similarities of wind input and dissipation are applied to the investigation of the fetch-limited growth of wind waves, together with the 3/2 power law presented by Toba. Some semi-empirical formulas concerning the growth of wave height and period with fetch are presented. The results from the formulas are in good agreement with previous field observations.展开更多
In this study, we present the nonlinear interactions between gravity waves (GWs) and tides by using the 2D numerical model for the nonlinear propagation of GWs in the compressible atmosphere. During the propagation in...In this study, we present the nonlinear interactions between gravity waves (GWs) and tides by using the 2D numerical model for the nonlinear propagation of GWs in the compressible atmosphere. During the propagation in the tidal background, GWs become instable in three regions, that is z = 75―85 km, z = 90―110 km and z = 115―130 km. The vertical wavelength firstly varies gradually from the initial 12 km to 27 km. Then the newly generated longer waves are gradually compressed. The longer and shorter waves occur in the regions where GWs propagate in the reverse and the same direction of the hori-zontal mean wind respectively. In addition, GWs can propagate above the main breaking region (90—110 km). During GWs propagation, not only the mean wind is accelerated, but also the amplitude of tide is amplified. Especially, after GWs become instable, this amplified effect to the tidal amplitude is much obvious.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.U1706216,41606024,41506023)the National Key Research and Development Program of China(Nos.2016YFC1402000,2018YFC1407003)+2 种基金the CAS Strategic Priority Project(No.XDA19060202)the NSFC Innovative Group Grant Project(No.41421005)the NSFC-Shandong Joint Fund for Marine Science Research Centers Grant(No.U1406402)
文摘In this study,typhoon waves generated during three typhoons(Damrey(1210),Fung-wong(1416),and Chan-hom(1509))in the Yellow Sea and East China Sea were simulated in a simulating waves nearshore(SWAN)model,and the wind forcing was constructed by combining reanalyzed wind data with a Holland typhoon wind model.Various parameters,such as the Holland fitting parameter(B)and the maximum wind radius?,were investigated in sensitivity experiments in the Holland model that affect the wind field construction.Six different formulations were considered and the parameters determined by comparing the simulated wind results with in-situ wind measurements.The key factors affecting wave growth and dissipation processes from deep to shallow waters were studied,including wind input,whitecapping,and bottom friction.Comparison with in-situ wave measurements suggested that the KOMEN scheme(wind input exponential growth and whitecapping energy dissipation)and the JONSWAP scheme(dissipation of bottom friction)resulted in good reproduction of the significant wave height of typhoon waves.A preliminary analysis of the wave characteristics in terms of wind-sea and swell wave revealed that swell waves dominated with the distance of R to the eye of the typhoon,while wind-sea prevailed in the outer region up to six to eight times the R values despite a clear misalignment between wind and waves.The results support the hypothesis that nonlinear wave-wave interactions may play a key role in the formation of wave characteristics.
文摘Investigated is the coupled response of a tension leg platform （TLP） for random waves. Inferred are the mass matrix, coupling stiffness matrix, damping matrix in the vibration differential equation and external load of TLP in moving coordinating system. Infinitesimal method is applied to divide columns and pontoons into small parts. Time domain motion equation is solved by Runge-Kutta integration scheme. Jonswap spectrum is simulated in the random wave, current is simulated by linear interpolation, and NPD spectrum is applied as wind spectrum. The Monte Carlo method is used to simulate random waves and fluctuated wind. Coupling dynamic response, change of tendon tension and riser tension in different sea conditions are analyzed by power spectral density （PSD）. The influence of approach angle on dynamic response of TLP and tendon tension is compared.
基金Project supported by 973 Project (Grant No: 2002CB412408) and the Natural Science Foundation of Qingdao (Grant No: 03-jr-15).
文摘The effects of waves on Surface Drag Coefficient （SDC） and surface mixing length were analyzed and discussed by carrying out three-dimensional current modeling for the Bohai Sea in the present work. A threedimensional coupled hydrodynamical-ecological model for regional and shelf seas （COHERENS） incorporating the influences of wave-current interactions was coupled with the third-generation wave model swan taking into account time-varying currents. The effects of waves on currents were included in the SDC, surface mixing length and bottom drag coefficient. Firstly, the formulations in Donelan were incorporated into the COHERENS to account for wave-dependent SDC. In order to compare simulation results for the wave-dependent SDC, the simulation for wind-dependent SDC was also carried out. Second, Wave-Induced Surface Mixing Length （described as WISML sometimes in this paper） was incorporated into the COHERENS. Four numerical experiments were conducted to discuss the effects of two kinds of wave processes. Generally, the values of time series of current velocity and water surface elevation given by the simulation with all of the three wave processes have a good agreement with observed data. The existence of WISML changes obviously current vertical profiles and the existence of the wave dependent SDC modifies the current field of both top and bottom layers with the wind-dependent SDC.
基金supported by the National Natural Science Foundation of China (Grant No.42276024)the National Natural Science Foundation of China (Grant No.41821004)+1 种基金the Basic Scientific Fund for National Public Research Institutes of China (Grant No.2022Q01)the Science and Technology of Laoshan Laboratory (Grant No.LSKJ202201600)。
文摘Due to the long-standing lack of understanding the role of wind waves on wind stress at moderate to high wind speeds,a high-frequency turbulence observation system is used in this study to obtain air-sea momentum flux data under pure wind wave conditions based on the tower-based marine meteorological observation platform in the southern Bohai Sea.Moreover,the modulation of wind waves on wind stress under wind speeds greater than 10 m s^(–1)is analyzed.The results indicated that the wind wave states caused by winds from the northwest and northeast are different under the influence of cold air,resulting in different wind stresses and drag coefficients.The wind stress increases with an increasing wind speed,reaching its maximum value when the northwest wind is nearly 20 m s^(–1),while the extreme value of the drag coefficient is basically the same when the northwest wind speed is the maximum and the northeast wind wave significant wave height is the maximum.The drag coefficient increases with an increasing wind speed within the range of 10–15 m s^(–1),reaching saturation at 15 m s^(–1).The critical wind speed is smaller than other observed results.Further analysis showed that wind-induced turbulent stress deviates from the observed values,and the degree of deviation depends on the wind speed and wave state,with a greater deviation caused by strong winds and waves.The wave-induced stress can correct the negative deviation between wind-induced turbulent stress and the observed value,and the drag coefficient calculated based on the modified wind stress tends to be close to the observed value overall.
基金This project is supported by the National Natural Science Foundation of China (Grant No.40276005), Natural Sci-ence Foundaton of Shandong Province (No.Z2002E01)and 863 Project(No.2001AA630307,2002AA639150)
文摘Based on observations from buoys, it is found that the wave age is well correlated with the nondimensional wave height, and this correlation is best described by a 3/5-power law. This similarity law is valid in the cases of wind waves as well as swells under natural sea states. On the basis of the 3/5-power law combined with the well-known 3/2-power law I it is shown that the wave-induced wind stress increases rapidly with wave age, indicating that the traditional observations or analytic techniques have only given the turbulent Reynolds stress induced by short wind waves, but excluded the long-wave-induced wind stress. The latter constitutes a small fraction to the total wind stress when the wave age is smaller than 1.0. The increase of sea-surface roughness with wave age can be attributed to wave breaking.
文摘The article solves the problem of surface gravitational waves using the theory of tangential discontinuity between media: air-water. Using the improved equation of mass continuity and taking into account the atmosphere inhomogeneity in the gravitational field of the Earth, it is shown that during wave processes, these two media mutually influence each other, which explains the reason for the formation of a stormy condition over the ocean and the drop in atmospheric pressure before the storm. The mechanism of the formation of the “killer wave” has been established and thus the “greatest mystery of nature” has been solved. The scale of wind and tsunami wavelengths has been established.
基金supported by the National Basic Research Program of China (Grant No. 2010CB428603)the National Natural Science Foundation of China (NSFC) (Grant No. 41025017)+1 种基金support of the research fellowships of NSFCthe Chinese Academy of Sciences
文摘Over the tropics, convection, wind shear （i.e., vertical and horizontal shear of wind and/or geostrophic adjustment comprising spontaneous imbalance in jet streams） and topography are the major sources for the generation of gravity waves. During the summer monsoon season （June August） over the Indian subcontinent, convection and wind shear coexist. To determine the dominant source of gravity waves during monsoon season, an experiment was conducted using mesosphere-stratosphere-troposphere （MST） radar situated at Gadanki （13.5°N, 79.2°E）, a tropical observatory in the southern part of the Indian subcontinent. MST radar was operated continuously for 72 h to capture high-frequency gravity waves. During this time, a radiosonde was released every 6 h in addition to the regular launch （once daily to study low-frequency gravity waves） throughout the season. These two data sets were utilized effectively to characterize the jet stream and the associated gravity waves. Data available from collocated instruments along with satellite-based brightness temperature （TBB） data were utilized to characterize the convection in and around Gadanki. Despite the presence of two major sources of gravity wave generation （i.e., convection and wind shear） during the monsoon season, wind shear （both vertical shear and geostrophic adjustment） contributed the most to the generation of gravity waves on various scales.
基金the National Natural Science Foundation of China(Grant Nos.51720105010,51979029)the Major Scientific and Technological Project of CNOOC(KJGG2022-0202)Innovative Research Foundation of Ship General Performance(Grant No.31422119).
文摘Wave slamming is an important phenomenon due to its destructive power,and with the rapid development of offshore wind turbines,wave slamming on vertical cylinders has garnered lots of attention.However,the phenomenon of wave slamming on vertical cylinders is very complicated due to both the intrinsic complexity of breaking waves and that of slamming forces.The objective of this paper is to provide a general review of research related to this problem,including theoretical methods,experimental studies,numerical simulations,and full-scale measurements.Based on these approaches,the momentum theory/pressure impulse theory,spatial distribution characteristics of impacts to various breaking waves,wave generation methods,analysis methods for measured forces under structure response,scale effects in experiments,and in-situ measurements have been introduced and discussed.Results show that simplifications in existing models for wave impacting such as wave characteristics and structural response reduce its applicability and should be studied further both in theoretical,experimental and numerical researches.
文摘In many areas around the world, wake surfing has been cited as one of the major causes of lakeshore erosion and turbidity. This paper quantifies the impact related to turbidity and erosion with the use of computational fluid dynamics (CFD) of boat wakes in shallow water and the build-up of wind driven waves. The energy, type and direction of the boat’s wake are described quantitatively and a table for predicting wind driven waves over varying fetches, depth and wind speeds is provided. The CFD simulation shows that if a wake surf boat is operated 200 ft from shore and in at least 10 ft of water, the environmental impact is minimal.
文摘Wind input parameterizations proposed by Jeffreys, Sverdrup and Munk, and Plant are analyzed. It is found by analogy that the similarity of integrals of the three wind input parameterizations exists. Wave breaking dissipation parameterizations proposed by Tsikunov, Hasselmann, and Phillips are also analyzed. Likewise it is found by analogy that the similarity of integrals of the three dissipation parameterizations exists. The similarities of wind input and dissipation are applied to the investigation of the fetch-limited growth of wind waves, together with the 3/2 power law presented by Toba. Some semi-empirical formulas concerning the growth of wave height and period with fetch are presented. The results from the formulas are in good agreement with previous field observations.
基金the National Natural Science Foundation of China (Grant Nos. 40621003, 40225011 and 40674088)the National Major Basic Research Project (Grant No. 2006CB806306)in part by the Foundation of the Key Laboratory of Geospace Environment & Geodesy of Ministry of Education, China
文摘In this study, we present the nonlinear interactions between gravity waves (GWs) and tides by using the 2D numerical model for the nonlinear propagation of GWs in the compressible atmosphere. During the propagation in the tidal background, GWs become instable in three regions, that is z = 75―85 km, z = 90―110 km and z = 115―130 km. The vertical wavelength firstly varies gradually from the initial 12 km to 27 km. Then the newly generated longer waves are gradually compressed. The longer and shorter waves occur in the regions where GWs propagate in the reverse and the same direction of the hori-zontal mean wind respectively. In addition, GWs can propagate above the main breaking region (90—110 km). During GWs propagation, not only the mean wind is accelerated, but also the amplitude of tide is amplified. Especially, after GWs become instable, this amplified effect to the tidal amplitude is much obvious.
