Two-dimensional Numerical Model Research Articles

Flow and Heat Transfer on the Surface of Molten Steel Slag Layer in Continuous Casting Mold

Protective slag is coated on the surface of molten steel during continuous casting, the flow and heat transfer state of the protective slag is a decisive factor affecting the inflow and consumption of liquid slag and is also an important prerequisite for stabilizing and improving the quality of continuous casting billets. Based on the Navier Stokes fluid momentum conservation equation and energy equation, a two-dimensional longitudinal numerical model describing the flow/heat transfer of liquid protective slag on the surface of steel is established. The data comes from the equipment parameters and casting process of an arc shaped slab continuous casting machine in a domestic steel plant. The flow field and temperature field distribution of protective slag are calculated and analyzed, and the effects of factors such as slag layer thickness and shear speed on the flow and heat transfer status of the liquid slag layer are discussed. When the bottom shear velocity increases from 0.005 m/s to 0.2 m/s, the maximum flow velocity of liquid slag from the nozzle to the narrow surface in the center area of the model increases from 0.0012 m/s to 0.0617 m/s, and the average longitudinal flow velocity of liquid slag near the nozzle increases from 0.0012 m/s to 0.0627 m/s. The research results provide reference for investigating the complex metallurgical behavior of protective slag.

Two-phase mass transporting under various operating conditions during mode switching of unitized regenerative fuel cell with non-uniform flow channels

ABSTRACT The electrolyzing and fuel cell (FC) modes appear in a unitized regenerative FC. Understanding the operating condition impacts on the dynamic behaviors during mode-switching procedure facilitates better handling of cell working states and increasing the performance behaviors. In the present paper, a two-dimensional transient numerical model is employed to discuss the influence of operating conditions on two-phase species distributions when switching the cell mode into FC. According to the numerical results, it is concluded that when the cell switches from electrolytic cell to the mode of FC, reducing the operating cell voltage can significantly improve the cell performance. At the same time, concentration polarization and temperature heterogeneity are serious. Increasing the gas inlet velocity can improve the cell performance. Providing the reaction gas with the same concentration as the FC mode in advance can improve the temperature uniformity and cell current density values when starting switching the mode but hardly impacts the parameter value and currents after stabilization.

Numerical study on hydrogen heterogeneous reaction characteristic in a micro catalytic combustor with blunt body

A numerical investigation has been conducted to explore the effect of an inserted blunt body on the heterogeneous reaction (HTR) characteristics in a micro-catalytic combustor operating with premixed hydrogen/air. The two-dimensional numerical model incorporates a comprehensive heterogeneous reaction mechanism of hydrogen employed by experimental verification. The influences of blockage ratio at various inlet velocities have been investigated to obtain optimized design parameters of the combustor. The findings of this research highlight analysis of the positive influence of an inserted blunt body within the combustor, including enhancement of chemical reaction rate and hydrogen conversion ratio. Numerical results shows that the gaseous mixture between the blunt body and catalytic surface noticed a considerable velocity increase, leading to a greater adsorption–desorption of bulk species on the catalytic surface. At the same inlet velocity, the hydrogen conversion ratio gradually increases with higher blockage ratios. When the blockage ratio is less than or equal to 0.6, the average inner wall temperature is positively affected by the increased blockage ratio. However, the effect becomes negative at higher blockage ratios (0.8). The Pr (Prandtl number) number near the gas–solid interface adjacent to the blunt body initially decreases and then increases, while Nu/Nu0 (Nusselt number) and Pe (Peclet number) exhibit an initial increase followed by a decrease. The presence of the blunt body leads to a reduction in the cross-sectional area of the channel, causing an acceleration in fluid velocity near the blunt body and exerting an impact on the boundary layer near the gas–solid interface. This indicates that the addition of the blunt body reduces the boundary layer thickness and enhances the mass and heat transfer characteristics in the region. The study reveal that as the blockage ratio increases, the overall field synergy of the combustor initially increases and then decreases. The peak field synergy is attained at an optimal blocking ratio of 0.6. The findings of this study have important implications for the design of micro-scale combustors.

Scour characteristics and dynamic mechanisms of the breakwater head in the abandoned Yellow River Delta on the northern Jiangsu coast, China

Breakwater scour seriously affects the safety and stability of breakwater foundation. Previous research has primarily focused on breakwater scour of sandy coasts, and to date, limited studies exist on silty–muddy coasts. This study analyzed the causes of scour around the breakwater head in Binhai Harbor, Jiangsu Province from the perspective of hydrodynamic changes and sediments based on years of field observation data and a two-dimensional tidal current numerical model. The observation results showed that four years after breakwater construction, a scour hole with a scour depth over 20 m formed in the northeast of the breakwater head. The development of the scour experienced a process of sudden acceleration, followed by slowing. After the construction of the breakwater, the tidal flow velocity near the breakwater head exceeded the critical motion velocity of the muddy clay layer, which was the main factor for the formation of the scour hole. Our findings indicate that when the scour tended to an equilibrium, the scouring area expanded to the northern and southern sides. This research provides a reference for studying morphodynamic change processes caused by the construction of marine structures on silty–muddy coasts.

Numerical Study on Overtopping Performance of Multi-stage Overtopping Wave Energy Converters

The characteristics of wave conditions with large tidal ranges and small wave heights in China's coastal waters limit the operation time of traditional single-stage overtopping devices, while the multi-stage overtopping wave energy converters can increase the overall operation time of the device by distributing the upper and lower reservoirs. To study the overtopping performance of the multi-stage overtopping wave energy converter under real sea conditions, a two-dimensional numerical model of the device is developed and verified by physical model tests. The effects of the lower reservoir opening width, slope angle combination, and slope inundation length on the overtopping performance are investigated under regular wave conditions. It is found that a smaller opening width and two 30° slope angles improve the overtopping performance of the device, while the slope inundation depth has less effect. Further, based on the full-scale prototype device, the database of overtopping in a complete tidal cycle (12h) were constructed under real sea conditions in different seasons to provide the basic data for the Wave-to-wire model of power generation simulation.

Numerical analysis of inclined demountable precast concrete walls with rocking-based composite columns for seismic protection of building structures

With the aim of simultaneously reducing all seismic demands, this paper proposes a novel structural system comprising inclined demountable walls with rocking base composite columns (IDWC). The proposed IDWC system combines the concepts of using inclined demountable walls in each story and rocking-based concrete filled steel tube (CFST) columns as the wall boundary elements. In particular, through inclined walls, the number of walls in each story is reduced, while with the use of rocking CFST columns, damage to the boundary elements can be mitigated. In total, 18 two-dimensional numerical models are developed and static as well as dynamic analyses are conducted to evaluate the performance of conventional and demountable wall systems of 4-, 10- and 15-stories height. For each height, 4 IDWC models, with various wall arrangements, and a vertical demountable wall model are analyzed and compared with a conventional reinforcement concrete wall model. For the studied models, micro and macro numerical models are developed and verified through experimental data. After performing cyclic and time history nonlinear analyses, it is shown that IDWC models have lower initial stiffness and higher energy dissipation capacity than the conventional model. According to these results, inter-story drift, floor acceleration, and base shear in IDWC models are reduced by up to 30%, 41%, and 45%, respectively, compared to the conventional model. Also, it is demonstrated that with the use of rocking CFST columns, the wall boundaries remain undamaged, which ensures any residual drifts after severe earthquakes are insignificant. Meanwhile, as the incremental dynamic analysis results show, the collapse capacity of IDWC models is up to 53.5% higher than that of conventional models.

Optimizing solidification process in phase change energy storage units with sinusoidal wave-shaped fins

Phase change energy storage units have attracted considerable interest in the field of energy storage technology. To overcome the challenge of low thermal conductivity associated with phase change material (PCM) employed in these units, researchers have implemented fins with various shapes. In this study, a two-dimensional numerical model of a phase change energy storage unit with newly designed sinusoidal wave-shaped fins is developed. The analysis is done using commercial software ANSYS-Fluent in the transient state. The solidification process of the PCM is evaluated with enthalpy–porosity method. The validation of the model is done against an experimental result from a published article. The study focused on increasing the surface area of sinusoidal wave-shaped fins, achieved by increasing its crests and troughs counts, and to analyse its impact on the solidification process of the PCM. The thermal performances are evaluated quantitatively by analysing the solidified portion of PCM, temperature distribution, rate of heat release, and velocity variation. The result shows that the total solidification time predicted for straight fin is 115.34 min. This duration reduces for wave-shaped fins, and it reduces even further as the crests and troughs counts of wave-shaped fins increases. The maximum reduction in total solidification time is observed as 19.93% for wave-shaped fin with 10 crests and troughs counts. It is also observed that rate of reduction in total solidification time initially decreases then marginally increases with the increase in crests or troughs counts. The effect of buoyancy on the PCM flow velocity is analysed at different locations within the phase change energy storage unit. It is observed that with the increase in crests and troughs counts the movement of PCM near the crest or trough decreases.

Blockage effect and ground effect on oscillating hydrofoil

Oscillating hydrofoils located in a channel or limited zone by two side walls will be affected by both the blockage effect and ground effect. To study the contribution of these two effects on the energy-extraction performance of hydrofoils, a two-dimensional numerical model was established based on the overset grid technology. The differences in the energy extraction of hydrofoil with different wall settings were compared, and the blockage effect and ground effect in the double-wall case were mainly studied. The results show that compared with the open flow field, the single-wall can only improve the hydrofoil energy extraction by 1.75%, while the double-wall with the same foil-wall spacing can greatly improve the oscillating hydrofoil efficiency by 19.34%. By linearly fitting the results at low blockage ratios and performing the subtraction process, the influence of blockage effect and ground effect can be separated preliminarily. These two effects have the same order of magnitude in improving the energy extraction of hydrofoils when the blockage ratio is high. In addition, the present study proposes to add the correction of the drag coefficient to remedy the shortcoming of the correction method proposed by Barnsley and Wellicome that cannot deal with the high blockage ratio cases, which means the influence of the ground effect is also corrected. Then the blockage effect and the ground effect can also be separated by the subtraction process. Based on the above analysis, it is found that the ground effect has little influence when the hydrofoil oscillates at high frequencies, while the influence of the blockage effect is mainly related to the blockage ratio rather than the oscillating frequency.

Revealing the role of limiting oxygen concentration test for a wick flame in characterizing the liquid fuel flammability

A two-dimensional numerical model was established to simulate the wick combustion system for determining the limiting oxygen concentration (LOC) of organic solvents, called the wick-LOC method. The ethanol wick flame under forced flow with decreased oxygen concentrations in normal gravity was studied numerically. Three simplified reaction mechanisms, 1-step, 2-step, and quasi-global mechanisms of ethanol were employed in the simulations for comparison with experimental results. The responses of flame height and edge flame standoff distance to the oxygen decrease were analyzed for validation. As the oxygen concentration was reduced to the stability limit of the full flame, the blow-off of the edge flame can be observed. By comparing the simulated LOCs and near-limit stabilized flame structures, the 2-step mechanism can reproduce the wick-LOC well, while the quasi-global mechanism can provide a more detailed flame structure. Further investigation into flame blow-off processes revealed that the reaction rate in fuel-lean conditions is more important for determining the wick-LOC, and the local flow velocities at the flame kernel are almost constant until blow-off occurs. By combining the flame stabilization theory with simulations, the physical meaning of the wick-LOC value can be explained as the oxygen concentration where the local flow velocity can be balanced with critical edge flame speed (more fundamentally, the critical laminar burning velocity) in a certain fuel-lean equivalence ratio. Further applications of the wick-LOC method are expected to examine the simplified reaction mechanisms of other liquid fuels.

Comparative study on melting and solidification processes of vertical shell-and-tube phase change heat exchanger with an improved conical inner tube

In previous studies, conventional conical structures fail to eliminate the bottom hard-to-melt zone, and assessment of the full cycle thermal performance of melting and solidification processes is lacking. The combination of the improved conical inner tube configuration with the reverse technique has not been reported. Given this, an improved conical inner tube configuration is proposed in this paper to improve melting performance. A two-dimensional numerical model of a thermal energy storage unit with an improved conical inner tube is established. The melting and solidification processes of phase change materials (PCMs) in the unit are numerically simulated to reveal its heat transfer and flow characteristics, and effects of the dimensionless bottom annular distance Sb' and the dimensionless tilt height Ht' of the configuration on the thermal characteristics are emphatically investigated. The results show that the utilization of the improved design effectively promotes the melting rate. However, it deteriorates the heat transfer performance of the solidification process. Therefore, the reverse technique (180° rotation) is adopted to improve the solidification rate. Results indicate that the solidification time of PCMs is remarkably reduced after the reverse layout, with a maximum reduction of 42.63% compared with configurations without reverse. The mode, the improved conical inner tube configuration with reverse layout, is suitable for scenarios where rapid charging is required through full-cycle thermal analysis.

Influence Analysis of Liquefiable Interlayer on Seismic Response of Underground Station Structure

To study the influence law of the seismic response of underground station structures at liquifiable interlayer sites, a two-dimensional numerical model of the interaction between the soil and station structure was established based on the finite difference software FLAC3D. The nonlinear dynamic response of the station structure located at the liquifiable interlayer site was analyzed considering the location distribution, relative density, and thickness of the liquifiable interlayer. The results show that the deformation of the structure is greatest when the liquifiable interlayer is distributed on both sides of the station side walls, while the interlayer has an energy-dissipating and damping effect on the upper station structure when it is located at the bottom of the structure. The lower the relative density of the liquifiable interlayer is, the stronger the internal dynamic response of the structure will be, and the more unfavorable it will be to the seismic resistance of the structure. When the liquefiable interlayer is only present in the lateral foundation of the station, an increase in its thickness results in a stronger shear effect on the structure and a higher probability of damage. However, when the thickness of the liquifiable interlayer reaches a point where the entire station is placed within it, the lateral force and deformation of the structure are significantly reduced.

Parametric Investigation of Interaction between Soil-Surface Structure and Twin Tunnel Excavation: A Comprehensive 2D Numerical Study

The growing demand for transportation tunnels in densely populated urban areas has led to the widespread adoption of twin tunnel configurations in contemporary infrastructure projects. This research focuses on investigating the complex interaction between soil, structures, and the excavation of twin tunnels. The study employs the tunnel boring machine (TBM) method and utilizes two-dimensional numerical modeling based on the finite element method (FEM). The numerical model is validated by comparing its results with field measurements obtained from a twin tunnel project in Italy, specifically the New Milan Metro Line 5. A comprehensive parametric study is conducted to analyze various parameters that influence soil–structure interaction during tunnel excavation. These parameters include the positioning of the tunnels in relation to each other, the spacing between them, the presence of structures above the tunnels, eccentricity between the structure axis and tunnel axis, and tunnel depth and diameter. Moreover, a comparative analysis is performed between scenarios with and without structures to elucidate the impact of structure presence on the interaction phenomenon. The research findings provide valuable insights into the intricate behavior of twin tunnels and their interaction with the surrounding soil and structures.

A novel two-dimensional numerical model developed for slope soil erosion

Simulated slope erosion sediment yield and its development process have great significance for quantitative evaluation of erosion and its sources. In this study, a loess slope erosion experiment was implemented indoors to establish a sediment transport capacity formula suitable for loess slope erosion. A two-dimensional slope erosion numerical model was developed with corrected sediment transport capacity formula, and the model was verified by a simulated indoor slope rainfall erosion experiment. The results showed that the corrected slope sediment transport capacity formula is suitable for loess slopes. The proposed two-dimensional slope erosion numerical model could simulate runoff and sediment processes in a relatively more accurate. The most severely eroded areas were the middle and lower parts on erosion spatial contribution based on the simulation erosion results. Good agreements between the simulated and observed results were found for erosion and its spatial distribution. The research results can further improve loessal slope erosion process simulation and prediction.

Transient responses of the linear and nonlinear gap resonances in the fixed and free-heaving moonpools

The transient responses in the fixed and free-heaving moonpools under the conditions of linear and nonlinear gap resonance are investigated. A two-dimensional numerical model was established using a constrained interpolation profile method-based in-house code. This paper mainly concentrates on the prediction and quantification of the developing and diminishing processes of the free-surface elevation at gap when encountering both the linear gap resonance and quadratic wave excitation (QWE)-driven gap resonance. The parameter analyses with respect to the distance between the barges and barge draft are considered to derive the variation in the response time and damping time. The continuous wavelet transform (CWT) is introduced to investigate the gap resonances for the first time to obtain the transient characteristics' distribution of the free-surface elevation at gap along time and frequency domains. Numerical results demonstrate that the heave motion has changed the developing patterns of both the linear gap resonance and QWE gap resonance in the free-heaving moonpool rather than those in the fixed moonpool. Nevertheless, the impact caused by heave is little as for the diminishment. By introducing a new hyperbolic-function-type amplification function, the development of the gap resonances for the free-heaving moonpool is well predicted. In addition, the opposite tendency is observed for both the response time and damping time between the fixed and free-heaving moonpools when considering from the linear to QWE gap resonances. According to the transient characteristics obtained from the CWT, it is attributed to the different proportions of the free-surface elevation's second-order component between the fixed and free-heaving moonpools at the QWE resonant point. Moreover, the duration of the damping time is found to be greatly influenced by the phase relation between the free-surface elevation at gap and the heave motion of the moonpool from the linear resonant point to the QWE resonant point.

CORRECTION OF OPTOACOUSTIC IMAGES USING BANACH'S THEOREM

The main aim of the work was the development and research of a numerical algorithm designed to correct artifacts and distortions that occur during image reconstruction in optical-acoustic tomography tasks. The task was to develop an algorithm capable of compensating for the peculiarities of the reconstruction method. The proposed iterative scheme for enhancing optoacoustic images is based on Banach's fixed point theorem. The problem of eliminating distortions and artifacts in optoacoustic images has been modeled and tested for four iterative schemes. Two-dimensional and three-dimensional numerical models were used to investigate the efficiency of the proposed algorithm. The optical-acoustic experiment simulated a biological environment with an object to be reconstructed built into it. The linear (2D case) or planar (3D case) detecting acoustic arrays located on the surface of the studied samples were considered. The reconstruction quality was determined using both the quantitative and visual estimates of the obtained results. The efficiency of the iterative algorithm of enhancing the reconstruction quality was quantitatively estimated using the structure similarity index SSIM and relative reconstruction error E. It was shown that the developed algorithm makes it possible to considerably improve the image quality as compared with the traditional optical-acoustic tomography methods even with a small number of iterations. Algorithms of the k-Wave Matlab toolbox software package were used for comparing. The results obtained in the work can be important from the standpoint of the prospects of their further practical application in the tasks of biomedical visualization.

Валидация численной модели плавления октадекана с помощью лабораторного эксперимента

The paper presents results of studying the melting process of octadecane, the heat-accumulating substance used in a space heat accumulator. The Stefan problem formulated for the phase transition boundary has an analytical solution only for the one-dimensional case. And in the case of the structure real geometry, it could be solved only using the numerical methods, in particular, by simulation in the ANSYS Fluent universal software system for the finite element analysis. To validate the developed numerical models, model experiments were carried out on octadecane melting in the cylindrical glass flask with heat-insulated side walls, the heater was positioned at the flask lower end. Two-dimensional and three-dimensional numerical models were investigated at the heating powers of 7.1 W and 34.2 W. The molten substance fraction dynamics in the two-dimensional and three-dimensional models was compared to the experimental data. Heat losses in heating the structure and convective heat exchange with the external media were taken into account. Results of numerical and laboratory experiments are presented, which could be used in testing the constant power heating model of a heat-accumulating substance. The results obtained show that with absolute temperature alteration in the heat-accumulating substance by an insignificant value (up to 10°C), the Boussinesq approximation provides results well verified by the experimental data.

An Efficient of Overlapping Grid Method with Scattering Technique in Time Domain for Numerical Modeling

An Overlapping Grid Method (OGM) with Biquadratic Spline Interpolation in scattering technique was developed to solve the direct and inverse scattering issues. A two-dimensional (2D) numerical image model was used to analyze the accuracy of the proposed method in a direct scattering process. It was discovered that when the sub-grid, sx ∆ increased, the absolute error for the electric field amplitude will also increase. The results also discovered that as the grid size ratio increased, the absolute error of the amplitude Z E will also increase. The findings show that smaller grid spacing and a finer grid size can produce more accurate results. The Overlapping Grid Method (OGM) with Biquadratic Spline Interpolation was expanded by incorporating with Forward-Backward Time Stepping (FBTS) technique to solve inverse scattering issues. Homogenous embedded objects with a square and circular shape are used to validate the efficiency of the proposed method. The findings showed that the proposed numerical method could detect and reconstruct embedded objects in different shapes. The efficiency of the proposed method was examined by Mean Square Error (MSE) and normalizing the functional error. The findings revealed that the MSE of dielectric profiles for the proposed method were lower than the FDTD method in FBTS. The relative permittivity and conductivity profile differed by 27.06% and 20%, respectively. Hence, it was proven that the proposed method successfully solved a known drawback to the FDTD method and produced more accurate and efficient results.

Heat losses in a trapezoidal cavity receiver of a linear Fresnel collector: A CFD approach

This paper presents a thermal study of a cavity receiver designed for a Fresnel-type linear solar collector (LFC). The study utilizes a two-dimensional computational fluid dynamics (CFD) model implemented in ANSYS Fluent. The thermal behavior of air inside the cavity for a Fresnel collector is extensively examined. The receiver consists of a trapezoidal cavity with a set of six parallel absorber tubes, through which a thermal fluid circulates. The cavity has aluminum reflectors on the inner walls and glass window closing the aperture facing the primary reflectors of the solar collector. The two-dimensional numerical model represents a cross-section of the receiver, and aims to provide numerical results that allow to provide algebraic correlations for predicting heat losses in the receiver from the wall temperature of each of the six individual absorber tubes that compose it. The developed model is transient, utilizing the k-ε turbulent model. In addition, the study is completed with an analysis of the behavior of the air surrounding and inside the cavity, to evaluate its thermal performance. For this purpose, the velocity and temperature contours obtained with the two-dimensional model are discussed. Correlations are obtained to know the heat flux between the tubes and the heat loss through the window for any combination of temperatures for each pair of tubes, which has not been yet studied in the literature. The study reveals that radiative losses contribute to 81% of the total heat losses, with the outer tubes temperature being the main responsible for these losses. Furthermore, a dimensionless analysis examines the relationship between the Nusselt and Rayleigh numbers in comparison to reference problems based on canonical geometries dominated by buoyancy-driven flows. The performance is found to be similar to that of a downward hot flat plate.

Comparative study of performance enhancement of latent thermal energy storage system with copper porous fin

Phase change material (PCM)-based thermal energy storage (TES) has attained significant attraction towards energy savings and ensures a continuous energy supply. However, the lower thermal conductivity of PCM impedes the efficient transfer in the storage systems, thereby causing longer charging time. Therefore, this paper introduces a novel heat transfer augmentation technique by incorporating copper porous fins in the shell-tube latent heat thermal energy storage. Further, to demonstrate the contribution of porous fins in heat transfer improvement, full-foam, solid-fin and without-fin TES systems are also evaluated and compared. A two-dimensional axisymmetric numerical model is developed and validated with in-house experimental results. It is found that conduction strongly affects the solidification process, exhibiting a greater response rate than the melting process of heat transfer enhancement techniques. Full-foam has higher melting and solidification rates, followed by solid-fin, porous-fin and without-fin. Compared to the without-fin configuration, the temperature response rates of the full-foam, solid-fin and porous-fin are improved by 169.9 %, 44.8 % and 41.88 %, respectively, during the melting process. Moreover, it is revealed that the porosity of foam has a marginally higher impact on the liquid fraction than the pore density. Further, the inclusion of porous-fin and full-foam leads to more uniform temperature distribution in PCM during melting and solidification compared to solid fin and without-fin. Therefore, the porous-fin and full-foam may be utilised for electronic cooling and battery thermal management, which requires uniform cooling at faster rates.

The effect of temperature on guided wave signal characteristics in presence of disbond and delamination for health monitoring of a honeycomb composite sandwich structure with built-in PZT network

Guided wave (GW) based structural health monitoring (SHM) techniques being developed by researchers frequently use amplitude and group velocity variations between healthy and damage-affected GW modes to detect and localise damage. Nonetheless, external variables such as temperature and moisture influence these features, which were not considered in previous studies, particularly in the presence of damage in honeycomb composite sandwich structures (HCSSs). Therefore, a coordinated numerical and experimental study was carried out in an effort to examine the characteristics of GW propagation in an HCSS for two damages: a disbond between the face sheet and the core, and delamination between the face sheet layers for a temperature range of 0 ∘C–90 ∘C. Computationally efficient two-dimensional numerical models were developed using COMSOL Multiphysics that takes into account a variety of temperature-related phenomena, such as thermal stresses and changes in the material properties of honeycomb sandwich and piezoelectric wafer transducers (PZTs). The amplitude and group velocity of the fundamental anti-symmetric (A0) mode are found to increase in the presence of a disbond and decrease in the presence of face sheet delamination. However, it is observed that there is a linear decrease in the amplitude of A0 mode for both the healthy and damaged cases with an increase in temperature. Since the A0 mode is widely employed for interrogation due to its defect sensitivity, an amplitude and group velocity adjustment equation with temperature change is proposed. Finally, considering the amplitude difference of normalised A0 mode, the two damages are localised within a network of PZTs by using a probability-based signal difference coefficient method, which is found to be efficient and reliable for SHM of HCSS under variable temperature conditions.