Amplitude Internal Solitary Waves Research Articles

Experimental study of the vertical structure of internal solitary waves in the continuous pycnocline

In order to reveal the complex structural characteristics of internal solitary waves (ISWs) in the actual ocean, an experimental study of the vertical structure of ISWs in the continuous pycnocline (a transition layer with sharp density changes) was conducted in a stratified fluid flume. The gravity collapse method was used to generate ISWs, and their wave-flow fields were measured using a coupled wave-flow measurement technique. The vertical structure of wave-flow fields was investigated as was the applicability of the Dubreil–Jacotin–Long (DJL) equation. The results show that the waveform of ISWs contains multiple isodensity lines that varied with fluid depth. The wave amplitude and wavelength of ISWs exhibited depth-dependent changes, which were negatively correlated. The vertical structure of the flow fields exhibited an approximate circular wave packet, with stronger horizontal flow than vertical flow. The larger the characteristic amplitude, the stronger the intensity of the flow field, and the faster the intensity of the vertical flow field increased. The applicability of the DJL equation was closely related to the stratified environment, with better agreement when the upper layer fluid constituted a larger ratio of the total fluid thickness.

Seasonal and Fortnight Variations in Internal Solitary Waves in the Indonesian Seas From the SWOT Measurements

AbstractUsing the wide‐swath sea surface height (SSH) data from the 1‐day repeat calibration/validation phase of the Surface Water and Ocean Topography (SWOT) mission, we explored fine‐scale evolution of nonlinear internal solitary waves (ISWs) in the Banda/Molucca Seas in the Indonesian Archipelagos. Generated in the Ombai Strait and Lifamatola Passage through semidiurnal tide‐topography interaction, respectively, ISWs in the Banda/Molucca Seas have a SSH amplitude of 10–20 cm and exhibit multiple wave packets with the leading wave crest followed by a series of rank‐ordered secondary wave crests. Due to nonlinearity, the ISWs are observed to propagate northward at a speed faster than the regional mode‐1 internal gravity waves and their amplitudes are modulated fortnightly following the regional spring‐neap tidal cycle. On longer timescale, the observed ISW amplitudes are controlled by seasonal upper ocean stratification changes with a weaker stratification favoring a larger amplitude. By converting the SWOT‐measured SSH data to the interior ocean pressure signals, we quantified the depth‐integrated energy flux associated with the northward‐propagating ISWs to be 5 and 2 kW m−1 in the central Banda and Molucca Seas, respectively. Comparisons with past studies indicate that the ISWs contribute to close to 100% and 40% of the tidally‐induced, northward energy fluxes, respectively, across the Banda and Molucca Seas.

The Interaction Between Internal Solitary Waves and Submarine Canyons

Internal solitary waves (ISWs) occur in stratified seawater and are characterized by substantial amplitudes and short periods. ISWs engender significant interactions between seawater and seafloor topography. They resuspend seabed sediments in various ways, and the submarine canyon acts as a main channel for transporting the suspended sediments from the shallow sea to the deep sea. Among the seas worldwide where ISWs are prevalent, the South China Sea exhibits the largest amplitude of ISWs, and the ISWs directly interact with the seafloor topography near the Dongsha area in the northern South China Sea. Through the analysis of the water profile and high-resolution multi-beam detection data in the vicinity of the Dongsha area, it was found that the submarine canyon exerts a great impact on the sediment resuspension and the bottom nepheloid layer formation induced by ISWs. The observation results show that the concentration of suspended particulate matter within the submarine canyon is remarkably higher than that outside the canyon. The concentration at the bottom of the canyon can reach twice that of the outside regions, forming a vast bottom nepheloid layer. In addition, with the presence of the submarine canyon, the suspended matter carried by the ISWs accumulates in the water column above the canyon, leading to a higher concentration above the canyon. This study deepens the understanding of the effect of ISWs on sediment resuspension in submarine canyons.

Non-Boussinesq effect on the internal solitary wave propagation under a Lagrangian-like description for various pycnocline thickness conditions

The Dubreil–Jacotin–Long (DJL) equation is an exact model for the steady propagation of internal solitary waves (ISWs) under Boussinesq approximation. The aim of this study is to discuss the non-Boussinesq effect on ISWs initialized by DJL equation for various pycnocline thickness conditions. The simulated results show that the non-Boussinesq effect can indeed lead to instability of DJL equation, and the pycnocline thickness will affect the amplitude of re-stable ISWs and the separation process of tail waves. Moreover, in order to extract features of the non-Boussinesq instability and the location of the tail wave separation, we propose an effective analytical approach for the quasi-traveling wave problem inspired by the definition of classical Lagrangian coherent structure (LCS). The improved finite-time Lyapunov exponent with a moving window (FTLEmw) is a Lagrangian-like description with considering the prior information of physical phenomenon. For a steady ISW propagation in the Boussinesq system, the repelling and attracting FTLEmv fields are symmetrical and the field ridge behaves as a continuous spiral topology, which suggests that particles on different streamlines in the flow structure have different rotation periods, while the streamlines are not actually completely closed due to the forward propagation of the wave. During the main unstable stage of non-Boussinesq effect, the topology of separated tail wave which is disconnected from the ISW main part can be clearly distinguished. The tail wave separation locations identified by the improved FTLEmv field and the classical FTLE field are not the same, which illustrates the difference between the two perspectives of flow structure change and fluid particle motion. In addition, the leading edge, trailing edge and main part of ISWs will gradually be divided into three-part FTLEmv topologies in the thicker pycnocline conditions.

Analysis of the Differences in Internal Solitary Wave Characteristics Retrieved from Synthetic Aperture Radar Images under Different Background Environments in the Northern South China Sea

Two internal solitary waves (ISWs) with very long fronts observed by synthetic aperture radar (SAR) images in the northern South China Sea (NSCS) are comparatively analyzed based on oceanic reanalysis data and the Korteweg–de Vries (KdV) theory. The differences in the environmental parameters, wave half-width, and amplitude of the two ISW fronts in the two distinct oceanic environments are studied. In the presence of a weak westward surface current of approximately 0.05 m/s, the values of the linear wave speed increase by up to 0.056 m/s, and the retrieved ISW amplitudes decrease by up to 14 m. On the contrary, for another background oceanic environment considering a relatively strong eastward surface current of approximately 0.2 m/s, there are decreases of up to 0.17 m/s in the linear wave speed and increases of up to 32 m in the retrieved amplitudes. However, the results retrieved from both the SAR observations commonly show that the ISW amplitudes along the fronts reach their maximums at roughly 21°N and decrease toward the southern and northern sides, in spite of their distinct background environments.

Experimental investigation of internal solitary wave loads on artificial seabed

The Next Generation Subsea Production System (NextGen SPS) is an innovative design for oil and gas production in ultra-deep ocean. As the most ingenious and significant part of this system, the artificial seabed (AS) is located at a certain depth under Mean Water Level (M.W.L) to avoid loads of conventional surface waves and surface currents. However, the strong shear currents, huge energy and enormous loads caused by internal solitary waves (ISWs) pose a threat to the security of the AS. Therefore, it is essential to study the loads of ISWs exerted on the AS. In the present paper, a number of laboratory experiments were conducted to compare the experimental and theoretical profiles of ISWs, and obtain the variation characteristics of the loads on the AS model. The effects of the ISW amplitude, the submerged depth of the AS model and the thickness ratio (TR) of the upper and lower layers (ULLs) of fluid on the loads acting on the AS model were discussed separately. The experimental results indicate that with the increase of the ISW amplitude, the maximum values of the horizontal force, vertical force and moment increased correspondingly. Under the condition of constant ISW amplitude, the maximum horizontal force is greater than the maximum vertical force, and the growth rate of the horizontal force is also higher than that of the vertical force. The horizontal force exhibits two peaks when the vertical position of the AS model is close to the pycnocline, and the difference between the peaks becomes smaller as the submerged depth of the AS model increases. Besides, the vertical force is more sensitive than the horizontal force and moment when the submerged depth of the AS model changes. The findings of this article can clearly reveal the action mechanism and load characteristics acting on the AS of ISWs, and provide necessary reference for the security of designing AS.

Effects of the inhomogeneous vertical structure of an internal solitary wave on the force exerted on a horizontal transverse cylinder

The vertical inhomogeneous structure of an internal solitary wave (ISW) in a continuous density pycnocline and its force exerted on a horizontal transverse cylinder are investigated theoretically and experimentally. The Dubreil–Jacotin–Long equation is used to describe the inhomogeneous vertical structure of the ISW, and a formula for calculating the vertical force on the cylinder in the inhomogeneous vertical structure is proposed. The inhomogeneous vertical structure of the ISW and its vertical force on a horizontal transverse cylinder are experimentally measured in a large stratified fluid flume. It is shown that the inhomogeneous vertical structure of the ISW is characterized by both inhomogeneous vertical distributions of ISW envelopes and amplitudes. The inhomogeneous vertical structure of the flow field is characterized by the shear distribution of the horizontal velocity above and below the continuous density pycnocline, as well as the reversed distribution of the vertical velocity on the windward and leeward sides of the ISW. The vertical force characteristics on the cylinder in the continuous density pycnocline, as well as the physical mechanism of the influence of the ISW inhomogeneous vertical structure on the vertical force, are obtained. The peak value of the vertical force on the cylinder situated at the pycnocline increases with the increase in ISW amplitude, and also, it increases and then decreases with the increase in submerged depth. Considering the inhomogeneous vertical structure characteristics of the ISW in an actual ocean environment, the average relative error in the vertical force calculation can be more effectively reduced by using the continuous density pycnocline force model than the strict two-layer fluid force model. The actual characteristics of ISWs in a stratified ocean environment can be objectively described, and the estimation accuracy of the vertical force on underwater objects can be greatly improved.

Experimental and observational analysis of vertical characteristics of internal solitary waves

The basic elements of internal solitary waves (ISWs) were obtained by vertically placed sensors in the laboratory experiment and in-situ observation. The vertical characteristics of the amplitude and waveform are analysed experimentally and observationally. Then the experimental and observational results were compared with the theoretical model. The study shows that the experimental amplitude-frequency relationship is closer to that in the two-layer model while the observational amplitude-frequency relationship is more approaching to that in the continuously stratified model. Experimental and observational results reveal that the amplitude of ISWs increase first and then decrease with an increasing depth. The sech2 function of the KdV theory can describe the waveforms of ISWs at different depths well.

On the identification of internal solitary waves from moored observations in the northern South China Sea

Based on the temperature data recorded by a mooring system deployed in the northern South China Sea (SCS), this study compares the traditional methods of identifying and extracting internal solitary waves (ISWs): the whole water column isotherm (WCI) method and the single isotherm (SI) method, and proposes a novel method: the temperature superposition (TS) method. Results indicate that the TS method identifies the most ISWs, followed by the WCI method, and the SI method identifies the fewest. When the ISW amplitudes are smaller than 60 m, the TS method can identify the most ISWs. When the ISW amplitudes are greater than 60 m, the number of ISWs identified by the three methods is the same. The TS method removes the internal tides, takes into account the temperature of all depth layers, and amplifies the signal of ISWs to a certain extent, so as to effectively identify ISWs.

Experimental and theoretical study of internal solitary wave loads on a submerged slender body

Based on the extended Korteweg de Vries (eKdV) theory and Morison's equation, a theoretical model of internal solitary wave (ISW) loads on a submerged slender body is investigated, and experimental measurements are further carried out in a large stratified fluid flume. The results show that the theoretical results are in good agreement with the experimental results. The horizontal force of the ISW on the slender body is consists of the horizontal dynamic pressure force and the friction force, in which the horizontal dynamic pressure force plays a dominant role. The vertical force includes the vertical wave force and the reduced gravity during the interaction between a slender body and an ISW. The magnitude of the force increases with increasing ISW amplitude, while its direction remains unchanged, and the force is closely related to the submerged depth of the slender body in the density pycnocline, which affects both the magnitude and the direction of the force.

Assessment of KdV and EKdV theories for simulating internal solitary waves in the continental slope of the South China Sea

Korteweg-de Vries (KdV) and Extended KdV (EKdV) are two important nonlinear theoretical models that are most commonly used for the description of internal solitary waves (ISWs). However, most of the previous studies based on the applications of these two models focus only on laboratory-based simulations. Moreover, the modeling data in those studies were rarely compared with the in-situ measurements. In this study, three moorings were deployed to the west of Dongsha Islands of the northern South China Sea (SCS), based on the KdV and EKdV theoretical approaches, to simulate and statistically analyze 854 mode-1 ISWs and 37 mode-2 ISWs captured during the period of observation. The results from this study indicated that both theories can be used to well describe the mode-1 ISWs with η0/H<0.12 (η0 and H are the amplitude of ISW and depth of seawater, respectively). Generally, when the depth of pycnocline was not close to H/2, the EKdV theory was more accurate than the KdV theory in simulating the waveforms and vertical velocities of mode-1 ISWs. However, for mode-1 ISWs with larger amplitudes, the horizontal velocities of the upper layer calculated by the EKdV theory were extremely large. The EKdV theory was no longer applicable when the depth of pycnocline was close to H/2 and η0 exceeded its limiting value of the EKdV theory. For mode-2 ISWs, the waveforms simulated by the EKdV theory were in close agreement with the in-situ measurements. However, neither of the two theories can accurately simulate the velocities. Further, the statistical results of propagation speeds of 49 mode-1 ISWs highlighted that the EKdV theory performed slightly better than the KdV theory in calculating the propagation speed of ISWs. Finally, the MCC (Miyata-Choi-Camassa) theory was introduced as a supplement to simulate larger-amplitude ISWs. The MCC theory was found to show better performance than the above two theories in simulating the ISWs with η0/H>0.15 but the trend was opposite when η0/H<0.15.

Numerical Simulation on Free Motion Response of a Submarine Induced by Internal Solitary Wave

Abstract：The internal solitary waves (ISWs) in the ocean carry huge energy and pose a serious threat to the safety of underwater vehicle. In order to obtain the dynamic response of the submarine under the action of ISWs, the amplified SUBOFF model was placed in a large numerical water tank with a length of 5000m, a width of 200m and a depth of 500m. The Korteweg-de Vries (KdV) theory was adopted to simulate the generation of ISWs in the two-layer flow, and overset grid technology was used to ensure the grid quality during the submarine movement. The results show that before the ISWs peak reaches the position of the submarine, the submarine will move, which causes the submarine to sink, move laterally and pitch. The longitudinal velocity is obviously greater than the lateral velocity, and the submarine finally hits the water tank bottom. With the increase of the ISWs amplitude, the time needed for submarine to reach the bottom increases, and the pitching angle increases greatly. The ISWs amplitude has no effect on the motion trajectory of the submarine's center of gravity, and has little effect on the lateral and longitudinal velocity. With the decrease of submergence depth of the submarine, the time required for submarine to reach the bottom will also increase, and the motion trajectory will change, but the trend of change is basically the same. The submergence depth has little influence on the variation range of lateral velocity, longitudinal velocity and pitching angle.

Effect of internal solitary wave on the dynamic response of a flexible riser

Dynamic responses can arise when a flexible riser encounters the internal solitary wave (ISW) in the ocean. It is, thus, necessary to explore its dynamical behaviors induced by ISW. First, the governing equations of the flexible riser, ISW, and hydrodynamic force are introduced and interpreted. The accordant validations are performed so as to examine the accuracy of the applied models. Then, the dynamic response of the flexible riser is studied with the increase of the nondimensional ISW amplitude. Representative characteristics, such as vortex-induced vibration (VIV), top tension, and stress along the flexible riser, are mainly analyzed and discussed. The results prove that with the propagation of ISW, VIV in both inline (IL) and crossflow (CF) directions can be incurred. The maximum values of IL and CF oscillation frequencies, top tension, inline deflection, as well as riser stress can be detected while the ISW trough reaches to the flexible riser. Furthermore, all these four dynamic characteristics show an increasing trend with the increase of the nondimensional ISW amplitude. Note that the maximum values of oscillation frequencies, inline deflection, and stress on the upper section of the flexible riser tend to be larger compared with those on the lower section. In addition, the maximum inline deflection, top tension, and stress along the flexible riser can be affected by VIV responses.

Observed internal solitary waves in the northern Bali waters, Indonesia

Internal solitary waves (ISWs) in the northern Bali waters are frequently observed via satellite imagery, but in situ observations remain scarce. Here, we report the northward propagating Lombok solitary waves from shipboard acoustic current measurements. The four leading waves have amplitude of 45, 35, 30, and 25 m and typical mean phase speed of ∼1.8 m s−1. The waves generated strong northward currents of ∼0.8 m s−1 in the upper layer and triggered vertical velocity that reaches ∼15 cm s−1. Those observations suggest larger ISWs amplitude than recent numerical estimates at the same location. The shape of the four leading waves is consistent with the Korteweg–de Vries (KdV) model. The total energy density within the packet reached ∼147 MJ m−1, and the total mean energy flux per tidal cycle into ISWs is in the range [0.6 – 1.0] GW, representing a strong fraction of the total northward baroclinic tidal energy flux estimated from models.

Investigation of the interaction of internal solitary waves with the slope-shelf topography

In this paper, internal solitary waves (ISWs) propagating over shelf topographies are studied based on numerical experiments conducted according to the lock-release method. The wave generation, propagation, and interactions with slope-shelf topography are investigated in a wave tank. The primary features of the propagation of ISWs on the slope are assessed. Shear and advection instabilities are observed in the current simulations in some cases with 1.29 &amp;lt; Bs &amp;lt; 1.75 (Bs is defined as the ratio of layer water depth on the shelf to the ISW amplitude). The induced density flow contributes to the growth of potential energy by dilution and stripping, primarily through its head, which is one of the factors used to enhance the mixing efficiency. In addition, the obtained results are compared with those of previous experiments conducted by other researchers, while considering the differences in local topography. The comparison reveals that local topography is a reason for the experimental differences of some research studies. ISW breaking on a slope is strongly influenced by the initial flow field of the slope, which may lead to differences in the prediction of the breaking point by using boundary layer separation as a criterion. As the incident wave amplitude increases, the location of the breaking point shifts downward and its magnitude gradually decreases.

Numerical study on the surface signature of internal solitary waves

The propagation of internal solitary waves (ISWs) underwater and their interactions with surface waves can affect the sea surface state and generate distinct surface signatures of bright–dark striped patterns in remote sensing imagery. These patterns have been one of the most important methods for wide coverage detection and observation of ISWs. This study establishes a fully nonlinear numerical model for ISW–surface wave interaction simulation based on the multi-domain boundary element method. By numerical simulation, the formation mechanism, characteristics, and influencing factors of ISW surface signatures are revealed. The physical essence of the ISW surface signature is the spatially inhomogeneous wavelength and roughness changes in the surface waves due to the convergence and divergence effects of the ISW. Based on the surface wave wavelength changes, the surface area affected by an ISW is divided into three regions from front to back—the converging, diverging, and restoring regions—corresponding to the regions where the surface waves are compressed, stretched, and recover, respectively. By comparing different cases, it is found that the ISW amplitude, surface wave amplitude, and surface wave wavelength are the main factors influencing the ISW surface signature. ISWs with larger amplitudes have stronger convergence and divergence effects on surface waves, making the overall scale of the ISW surface signature larger. Larger surface wave amplitudes provide stronger resistance to the ISW divergence effect and lead to smaller diverging regions, and larger surface wave wavelengths make the converging region larger and the diverging and restoring regions smaller.

Regional study of mode-2 internal solitary waves at the Pacific coast of Central America using marine seismic survey data

Abstract. In this paper, a regional study of mode-2 internal solitary waves (ISWs) at the Pacific coast of Central America is carried out using the seismic reflection method. The observed relationship between the dimensionless propagation speed and the dimensionless amplitude (DA) of the mode-2 ISW is analyzed. When DA &lt; 1.18, the dimensionless propagation speed seems to increase with increasing DA, divided into two parts with different growth rates. When DA &gt; 1.18, the dimensionless propagation speed increases with increasing DA at a relatively small growth rate. We suggest that the influences of seawater depth (submarine topography), pycnocline depth, and pycnocline thickness on the propagation speed of the mode-2 ISW in the study area cause the relationship between dimensionless propagation speed and DA to diversify. The observed relationship between the dimensionless wavelength and the DA of the mode-2 ISW is also analyzed. When DA &lt; 1, the nondimensional wavelengths seem to change from 2.5 to 7 for a fixed nondimensional amplitude. When DA &gt; 1.87, the dimensionless wavelength increases with increasing DA. Additionally, the seawater depth has a great influence on the wavelength of the mode-2 ISW in the study area. Overall, the wavelength increases with increasing seawater depth. As for the vertical structure of the amplitude of the mode-2 ISW in the study area, we find that it is affected by the nonlinearity of the ISW and the pycnocline deviation (especially the downward pycnocline deviation).

Experimental investigation on the three-dimensional oblique interaction of an internal solitary wave with a horizontal finite-length cylinder

An experiment on the oblique interaction of an internal solitary wave (ISW) with a horizontal finite-length cylinder was conducted in a gravitationally stratified fluid flume. The multi-measuring technique, which was composed of the multichannel conductivity-probe array, dyeing identification and particle image velocimeter (PIV), was used to study the coupling wave–flow structure, and the three-component micro-amplitude force sensor was used to measure the horizontal longitudinal, horizontal transverse and vertical forces on the cylinder. Based on the experimental observations and measurements, a theoretical analysis method of the three-dimensional force on the cylinder interacting with an ISW at any angle was established for the experimental analysis. The ISW force on the cylinder is composed of the wave force, the friction force and the disturbance force, in which three components of the wave force in the horizontal longitudinal, horizontal transverse and vertical directions can be estimated by the Morison formulas corresponding to those component velocities perpendicular to their respective directions, the dynamic friction force depends on the tangential velocity at the surface of the cylinder, additionally the disturbance force composed of the reduced gravity and the vortex shedding lift is considered in the vertical direction. Furthermore, it is found that the wave–flow structure of the ISW at its windward side, leeward side and inside its wave profile dominates the three-dimensional force on the horizontal finite-length cylinder, of which its characteristics change with key factors such as the interaction angle between the cylinder and the ISW, the incident ISW amplitude and the cylinder-submerged depth. When the interaction angle increases, the same order of the horizontal transverse force at a certain angle as the increasing horizontal longitudinal force can be gotten, and the ”double peak” of the vertical force can be made. With the increase of the incident amplitude, the magnitude of the three-dimensional force always increases, but its direction is unchanged. For different submerged depths, the vertical force depends on the ratio of the reduced gravity or the vortex shedding lift or their resultant force to the vertical disturbance pressure. However, the understanding of the oblique interaction mechanism of an ISW with a horizontal finite-length cylinder provides direct insight into the intrinsic characteristics of the damage to the safety of marine and offshore structures in the actual ocean.

Laboratory Study of the Impact of the Surface Solitary Waves Created by the Internal Solitary Waves on Optical Imaging

AbstractThe effects of Surface Solitary Waves (SSWs), which are created by Internal Solitary Waves (ISWs), on optical imaging were investigated in this paper. We explored the connection between SSWs and optical images using simulations and experiments with calm water surface conditions. An experimental platform was built in a controlled laboratory environment where optical images and in‐situ wave data could be gathered simultaneously. SSWs created by different ISWs were successfully observed. The optical images revealed inverse bright and dark patterns for different ISW types (depression or elevation type). Based on theories and experimental results, simulation models of the ISWs and SSWs were built in Unigraphics NX. Using the illumination simulation function of Light Tools, the reason underlying the reversed patterns was explained by the irradiance distribution. Both the experiment and simulation indicated that the SSWs created by the ISWs affected the characteristics of optical images. To further explore how SSWs affect imaging, 16 experiments were designed to investigate the effects of ISW type, amplitude, and water density ratio. It is found that the relationship among the SSW amplitude, ISW amplitude, and density ratio was consistent with earlier studies. The relationships between imaging characteristics (grayscale differences and pattern widths) and the two types of SSWs were consistent.

ISWFoam: a numerical model for internal solitary wave simulation in continuously stratified fluids

Abstract. A numerical model, ISWFoam, for simulating internal solitary waves (ISWs) in continuously stratified, incompressible, viscous fluids is developed based on a fully three-dimensional (3D) Navier–Stokes equation using the open-source code OpenFOAM®. This model combines the density transport equation with the Reynolds-averaged Navier–Stokes equation with the Coriolis force, and the model discrete equation adopts the finite-volume method. The k–ω SST turbulence model has also been modified according to the variable density field. ISWFoam provides two initial wave generation methods to generate an ISW in continuously stratified fluids, including solving the weakly nonlinear models of the extended Korteweg–de Vries (eKdV) equation and the fully nonlinear models of the Dubreil–Jacotin–Long (DJL) equation. Grid independence tests for ISWFoam are performed, and considering the accuracy and computing efficiency, the appropriate grid size of the ISW simulation is recommended to be 1/150th of the characteristic length and 1/25th of the ISW amplitude. Model verifications are conducted through comparisons between the simulated and experimental data for ISW propagation examples over a flat bottom section, including laboratory scale and actual ocean scale, a submerged triangular ridge, a Gaussian ridge, and slope. The laboratory test results, including the ISW profile, wave breaking location, ISW arrival time, and the spatial and temporal changes in the mixture region, are well reproduced by ISWFoam. The ISWFoam model with unstructured grids and local mesh refinement can effectively simulate the evolution of ISWs, the ISW breaking phenomenon, waveform inversion of ISWs, and the interaction between ISWs and complex topography.