Digital Particle Image Velocimetry Research Articles

Reconstruction method considering the electrostatic signal waveform of velocity distribution in flame based on EST

The velocity distribution of flame is an important combustion dynamic parameter that is used to analyze the stability, heat transfer and propagation of combustion. Digital particle image velocimetry and laser Doppler velocimetry are commonly used to measure the velocity distribution of flame. However, these methods work by adding tracer particles into the flame. A dual-section electrostatic tomography (EST) system is designed to detect the induction signal of the charged particles generated by the ionization process of combustion. The velocity distribution of flame is reconstructed through the electrostatic direct velocity tomography (EDVT) method. However, the different distance between the movement trajectory of the charged particles and a pair of electrodes for the cross-correlation calculation causes the difference in the induced signal waveform. It leads to an error in the cross-correlation velocity calculation. By analyzing the influence of the single charge induction signal waveform on the calculation of cross-correlation velocity, the reason for this error is clarified. Therefore, an electrostatic signal-waveform-based direct velocity tomography (ESDVT) method is proposed. The experimental results from a belt-type electrostatic device show that the average value of the L2-norm error of the ESDVT method is reduced by 40.9% compared with the EDVT method. Finally, using the method proposed in this paper, the velocity distribution at different sections of the Meker flame is reconstructed without adding tracer particles.

Label-free 3D tracking of biological micro-objects using RGB pinholes

Defocusing digital particle image velocimetry is a method developed within the field of fluidics to measure the velocities of particles within a volume through image analysis. For three-dimensional (3D) tracking, approaches utilizing defocusing techniques have been proposed to enable depthwise positional measurements. Recently, there have been suggestions to simplify this approach by employing a triple pinhole mask and to further enhance it with color filters that allow distinguish particles, even under dense conditions. This paper presents an attempt to apply the defocusing method using a triple pinhole mask with red, green, and blue (RGB) color-coding filters, demonstrating the successful label-free 3D tracking of biological micro-objects at multiple positions within a volume. The application of this method in fluidics and its potential for biological analysis are highlighted through successful examples of 3D tracking involving micro-particles influenced by motor proteins, dividing cells, and swimming microorganisms.

Hydrodynamic Insights on Floating Bubbling Fluidized Beds: Dynamic Solutions for Mitigating Gas Maldistribution

This study examined bubbling fluidized beds as an alternative to fixed-bed dry scrubbers on ships for reducing pollutants from marine fuels. It focused on overcoming the challenges of gas maldistribution/slug formation, especially under rough sea conditions. This research departed from traditional methods by introducing mobile internal elements into the bed emulsion phase and investigating their effectiveness in various settings, such as vertical, inclined, and rolling beds. A specialized hexapod-driven bubbling fluidized bed was developed to mimic marine operating conditions and to study the behavior of shipboard fluidized beds. Techniques such as digital image analysis (DIA) and particle image velocimetry (PIV) were used to observe bubble dynamics and granular phases, measuring local void fractions and particle velocities. A key finding is the effectiveness of moving internals in preventing bubble coalescence, which is critical for avoiding wall slugs, at different inclinations. Three types of packing were used as mobile internals: Super Raschig, Pall, and square rings. Super Raschig rings, which are characterized by high porosity, were the most efficient in reducing bubble coalescence, making them a preferred choice for offshore fluidized bed applications. This research contributes to the advancement of fluidized bed technology in marine applications and provides insight for future improvements.

A 3D-Printed Micro-Optofluidic Chamber for Fluid Characterization and Microparticle Velocity Detection.

This work proposes a multi-objective polydimethylsiloxane (PDMS) micro-optofluidic (MoF) device suitably designed and manufactured through a 3D-printed-based master-slave approach. It exploits optical detection techniques to characterize immiscible fluids or microparticles in suspension inside a compartment specifically designed at the core of the device referred to as the MoF chamber. In addition, we show our novel, fast, and cost-effective methodology, dual-slit particle signal velocimetry (DPSV), for fluids and microparticle velocity detection. Different from the standard state-of-the-art approaches, the methodology focuses on signal processing rather than image processing. This alternative has several advantages, including the ability to circumvent the requirement of complex and extensive setups and cost reduction. Additionally, its rapid processing speed allows for real-time sample manipulations in ongoing image-based analyses. For our specific design, optical signals have been detected from the micro-optics components placed in two slots designed ad hoc in the device. To show the devices' multipurpose capabilities, the device has been tested with fluids of various colors and densities and the inclusion of synthetic microparticles. Additionally, several experiments have been conducted to prove the effectiveness of the DPSV approach in estimating microparticle velocities. A digital particle image velocimetry (DPIV)-based approach has been used as a baseline against which the outcomes of our methods have been evaluated. The combination of the suitability of the micro-optical components for integration, along with the MoF chamber device and the DPSV approach, demonstrates a proof of concept towards the challenge of real-time total-on-chip analysis.

The Mechanism of Droplet Thermocapillary Migration Coupled with Multi-Physical Fields

In this paper, the coupling effect of multiphysical fields of droplet migration is deeply studied by constructing a physical model of droplet migration with multiphysical fields. Digital holographic interferometry and particle image velocimetry are used to simultaneously measure the temperature and velocity fields of the mother liquor in the process of droplet migration for the first time. Due to the advancements of measuring, the zero-velocity region is also in the region where the thermal wake appears, four vortexes appear in the droplet migration and the off-axis behavior of double-droplet migration is found. The aim of this work is to analyze the coupling relationship of multiphysical fields, so as to reveal the physical laws of thermocapillary migration of single droplet and multiple droplets with the same phase and heterophase and to study the driving mechanism of the thermocapillary force and the flow of the mother liquor.

Segmental biomechanics of the normal and glaucomatous human aqueous outflow pathway

The conventional aqueous outflow pathway, encompassing the trabecular meshwork (TM), juxtacanalicular connective tissue (JCT), and inner wall endothelium of Schlemm's canal (SC), governs intraocular pressure (IOP) regulation. This study targets the biomechanics of low-flow (LF) and high-flow (HF) regions within the aqueous humor outflow pathway in normal and glaucomatous human donor eyes, using a combined experimental and computational approach. LF and HF TM/JCT/SC complex tissues from normal and glaucomatous eyes underwent uniaxial tensile testing. Dynamic motion of the TM/JCT/SC complex was recorded using customized green-light optical coherence tomography during SC pressurization in cannulated anterior segment wedges. A hyperviscoelastic model quantified TM/JCT/SC complex properties. A fluid-structure interaction model simulated tissue-aqueous humor interaction. FluoSpheres were introduced into the pathway via negative pressure in the SC, with their motion tracked using two-photon excitation microscopy. Tensile test results revealed that the elastic moduli of the LF and HF regions in glaucomatous eyes are 3.5- and 1.5-fold stiffer than the normal eyes, respectively. The FE results also showed significantly larger shear moduli in the TM, JCT, and SC of the glaucomatous eyes compared to the normal subjects. The LF regions in normal eyes demonstrated larger elastic moduli compared to the HF regions in glaucomatous eyes. The resultant strain in the outflow tissues and velocity of the aqueous humor in the FSI models were in good agreement with the digital volume correlation and 3D particle image velocimetry data, respectively. This study uncovers stiffer biomechanical responses in glaucomatous eyes, with LF regions stiffer than HF regions in both normal and glaucomatous eyes. Statement of significanceThis study delves into the biomechanics of the conventional aqueous outflow pathway, a crucial regulator of intraocular pressure and ocular health. By analyzing mechanical differences in low-flow and high-flow regions of normal and glaucomatous eyes, this research unveils the stiffer response in glaucomatous eyes. The distinction between regions' properties offers insights into aqueous humor outflow regulation, while the integration of experimental and computational methods enhances credibility. These findings have potential implications for disease management and present a vital step toward innovative ophthalmic interventions. This study advances our understanding of glaucoma's biomechanical basis and its broader impact on ocular health.

[In Vitro Experimental Study on Hemodynamics of Transcatheter Aortic Valve Replacement].

The patient-specific aortic silicone model was established based on CTA data. The digital particle image velocimetry (DPIV) test method in the modified ViVitro pulsatile flow system was used to investigate the aortic hemodynamic performance and flow field characteristics before and after transcatheter aortic valve replacement (TAVR). The results showed that the hemodynamic parameters were consistent with the clinical data, which verified the accuracy of the model. From the comparative study of preoperative and postoperative effective orifice area (0.33 cm2 and 1.78 cm2), mean pressure difference (58 mmHg and 9 mmHg), percentage of regurgitation (52% and 8%), peak flow velocity (4.60 m/s and 1.81 m/s) and flow field distribution (eccentric jet and uniform jet), the immediate efficacy after TAVR is good. From the perspective of viscous shear stress and Reynolds shear stress, the risk of hemolysis and thrombotic problems was low in preoperative and postoperative patient-specific models. This study provides a set of reliable DPIV testing methods for aortic flow field, and provides biomechanical basis for the immediate and long-term effectiveness of TAVR from the perspective of hemodynamics and flow field characteristics. It has important application value in clinical diagnosis, surgical treatment and long-term evaluation.

Bubble and particle dynamics in a thin rectangular bubbling fluidized bed under emulated marine instabilities

Floating fluidized beds are affected by swell/sea waves, limiting their effectiveness in seagoing applications as an alternative to fixed beds for the removal of exhaust pollutants. To address this, experiments were conducted using a rectangular fluidized bed mounted on a hexapod to emulate marine operation. The bed was subjected to dynamic perturbations, and Digital Image Analysis and Particle Image Velocimetry were used to analyze the effects of motion on fluidization, bubble growth/shape, void/velocity fields, and gas/solids circulations. Our investigation showed that non-vertical orientations resulted in a decrease in minimum fluidization velocity, but the most significant effect was seen in the trajectory and shape of the bubbles near both static and dynamic walls. This resulted in a slug regime with a high degree of gas bypass. These outcomes have important implications for the design/operation of marinized fluidized beds, and for process intensification solutions to address the constraints associated with ship emissions.

Experimental study on the electrohydrodynamic deformation of droplets in a combined DC electric field and shear flow field

• Electrohydrodynamic deformation of droplet in combined electric field and shear flow is studied. • Internal flow of the deformed droplet is quantitatively examined via the DPIV method. • Competition of actions from electric field and shear flow on droplet deformation is clarified. • Prediction model is modified and demonstrated to quantitatively represent droplet deformation. A visualization experiment was conducted to investigate the electrohydrodynamic deformation of droplets in a combined DC electric field and shear flow field. Detailed experimental data on both the transient and steady droplet deformation parameters ( D ) and orientations ( ϕ d ) are provided at R > S and R < S ( R : conductivity ratio; S : permittivity ratio) under different electric field and shear flow field combinations. The internal flow characteristics of the deformed droplet were also examined via the digital particle image velocimetry (DPIV) method. Due to the competition of the extensional component (EC) and the rotational component (RC) of these two fields on the droplet, the response of ϕ d is faster than that of D when an electric field is combined with a shear flow. Additionally, under the competition of the EC and RC at R > S and R < S , the steady-state D and ϕ d values exhibit distinct variations. In particular, surface charge convection plays a non-negligible role in enhancing and reducing droplet deformation at R > S and R < S , respectively. In addition, an asymmetric vortex forms inside the deformed droplet in the combined fields, and its velocity is lower under R > S and higher under R < S than in pure shear flow. The available prediction models use the experimental data to predict D , and a modified prediction model is proposed for improving the prediction accuracy of ϕ d .

Pitching foil propulsion performance decays near the free surface

A series of experiments reveal the non-linear relationship between the propulsive performance of a pitching foil and its distance to the free surface. An especially designed robotic device allowed to sinusoidally actuate a symmetric NACA 0021 profile, with its shaft being perpendicular to the free surface, at different separations from it, whilst measuring hydrodynamic loads, power and efficiency. Digital Particle Image Velocimetry (DPIV) was used to study the flow structures around the flapping system, to better understand the performance trends observed.Efficiency dropped more than a 40% when the foil was placed at a distance of approximately 5 to 10% of the span of the system, as a consequence of a large decrease in thrust and a large increase in power, both clearly linked to wake formation.

Lagrangian mixing of pulsatile flows in constricted tubes

Several Lagrangian methods were used to analyze the mixing processes in an experimental model of a constricted artery under a pulsatile flow. Upstream Reynolds number Re was changed between 1187 and 1999, while the pulsatile period T was fixed at 0.96 s. Velocity fields were acquired using Digital Particle Image Velocimetry for a region of interest (ROI) located downstream of the constriction. The flow is composed of a central jet and a recirculation region near the wall where the vortex forms and sheds. To study the mixing processes, finite-time Lyapunov exponents (FTLE) fields and concentration maps were computed. Two Lagrangian coherent structures (LCS) responsible for mixing fluid were found from FTLE ridges. A first LCS delimits the trailing edge of the vortex, separating the flow that enters the ROI between successive periods. A second LCS delimits the leading edge of the vortex. This LCS concentrates the highest particle agglomeration, as verified by the concentration maps. Moreover, from particle residence time maps, the probability of a fluid particle leaving the ROI before one cycle was measured. As Re increases, the probability of leaving the ROI increases from 0.6 to 0.95. Final position maps rf were introduced to evaluate the flow mixing between different subregions of the ROI. These maps allowed us to compute an exchange index between subregions, EI¯, which shows the main region responsible for the mixing increase with Re. Finally, by integrating the results of the different Lagrangian methods, a comprehensive description of the mixing and transport of the flow was provided.

Experimental Observations on Flow Characteristics around a Low-Aspect-Ratio Wall-Mounted Circular and Square Cylinder

The mean wake structures of a cube (square cylinder) and circular cylinder of height-to-width aspect ratio 1.0, at a Reynolds number of 1.78 × 104 based on the obstacle width, were investigated experimentally. The boundary-layer thickness was 0.14 of the obstacle height. The study was performed using thermal anemometry and two-dimensional digital particle image velocimetry (DPIV). Streamwise structures observed in the mean wake for both cylinders included well-known tip- and horseshoe (HS)-,vortex pairs as well as additional structures akin to the base vortices. In addition to tip-, base-, and HS-vortices, in the near wake of the cube, two more counter-rotating pairs of streamwise structures, including upper and inboard vortices, were observed. The existence of base vortices formed in the near wake for both obstacles is a unique observation and has not been previously reported for such low-aspect-ratio obstacles in thin boundary-layers. A model of arch-vortex evolution was proposed, in which arch structures were deformed by the external shear-flow to explain the observed base-vortices in the cylinder wake. A weak dominant-frequency of St = f0D/U∞ = 0.114 was observed across the height for the cube, while no discernible spectral peaks were apparent in the wake of the cylinder. Cross-spectral analysis revealed the shedding to be symmetric (in-phase) arch-type for the cylinder and predominantly anti-symmetric (out-of-phase) Karman-type for the cube. The study makes fundamental contributions to the understanding of the flow-field surrounding low-aspect-ratio cylinders.

Cell counting and velocity algorithms for hydrodynamic study of unsteady biological flows in micro-channels.

In this paper, the combination of two algorithms, a cell counting algorithm and a velocity algorithm based on a Digital Particle Image Velocimetry (DPIV) method, is presented to study the collective behavior of micro-particles in response to hydrodynamic stimuli. A wide experimental campaign was conducted using micro-particles of different natures and diameters (from to ), such as living cells and silica beads. The biological fluids were injected at the inlet of a micro-channel with an external oscillating flow, and the process was monitored in an investigated area, simultaneously, through a CCD camera and a photo-detector. The proposed data analysis procedure is based on the DPIV-based algorithm to extrapolate the micro-particles velocities and a custom counting algorithm to obtain the instantaneous micro-particles number. The counting algorithm was easily integrated with the DPIV-based algorithm, to automatically run the analysis to different videos and to post-process the results in time and frequency domain. The performed experiments highlight the difference in the micro-particles hydrodynamic responses to external stimuli and the possibility to associate them with the micro-particles physical properties. Furthermore, in order to overcome the hardware and software requirements for the development of a real-time approach, it was also investigated the possibility to detect the flows by photo-detector signals as an alternative to camera acquisition. The photo-detector signals were compared with the velocity trends as a proof of concept for further simplification and speed-up of the data acquisition and analysis. The algorithm flexibility underlines the potential of the proposed methodology to be suitable for real-time detection in embedded systems.

Base friction testing methodology for the deformation of rock masses caused by mining in an open-pit slope

Mining in an open-pit slope results in the deformation and instability of rock masses. Correspondingly, it is difficult to quantify the range of internal rock mass damage completely. In this study, a base friction testing method is proposed for the analysis of mining models in an open-pit slope, and new methodology is proposed which combines digital image correlation (DIC) and particle image velocimetry (PIV) techniques to analyze the entire deformation process. A series of base friction tests is performed to reveal the deformation mechanism of the mining model in an open-pit slope, and findings are compared with those obtained from a mining model without an open-pit slope. The test results showed two different types of damage: staged parabolic-like and progressive trapezoidal-like damages. Moreover, the proposed methodology can obtain the entire displacement and velocity vector distributions (from deformation to damage) inside the slope and convert it into data for visualization. This provides a reference for the evaluation and control of field open-pit slopes in similar conditions.

On the Turbulent Drag Reduction Effect of the Dynamic Free-Slip Surface Method

The turbulent boundary layer (TBL) over the hull surface of a water vehicle significantly elevates the drag force on the water vehicle. In this regard, effectively controlling the TBL can lead to a drag reduction (DR) effect and therefore improve the energy efficiency of water transportation. Many DR methods have demonstrated promising DR effects but face challenges in implementation at the scale of engineering application. In this regard, the recently developed dynamic free-slip surface method can resolve some of the critical challenges. It employs an array of freely oscillating air–water interfaces to manipulate the TBL and can achieve a substantial DR effect under certain control conditions. However, the optimal setting of the control parameters that would maximize the DR effect remains unclear. To answer these questions, this study systematically investigates the effects of multiple control parameters for the first time, including the geometric size and curvature of the interface, the frequency of active oscillation, and the Reynolds number of TBL. Digital Particle Image Velocimetry was used to non-invasively measure the velocity and vorticity field of the TBL, and the Charted Clauser method was used to calculate the DR effect. The presented results suggest that the oscillating free-slip interfaces reduce the flow velocity near the wall boundary and lift the transverse vorticity (and the viscous shear stress) away from the wall. In addition, the shape factor of the TBL is elevated by the oscillating interfaces and slowly relaxes back in the downstream regions, which implies a partial relaminarization process induced in the TBL. Up to 36% DR effect was achieved within the current scope range of the control parameters. All of the results consistently suggest that a large DR effect is achieved when the free-slip interfaces oscillate with large Weber numbers. These discoveries shed light on the underlying DR mechanism and provide guidance for the future development of an effective drag control technique based on the dynamic free-slip surface method.

Droplet breakup in airflow with strong shear effect

The deformation and breakup of droplets in airflows is important in spray and atomisation processes, but the shear effect in non-uniform airflow is rarely reported. In this study, the deformation and breakup of droplets in a shear flow of air is investigated experimentally using high-speed imaging, digital image processing and particle image velocimetry. The results show that in airflow with a strong shear effect, the droplet breakup exhibits unique features due to the uplift and stretching produced by the interaction between the deformed droplet and the shear layer. The breakup process can be divided into three stages according to the droplet morphology and the breakup mechanism, namely the sheet breakup, the swing breakup and the rim breakup stages. Theoretical analysis reveals that the swing breakup is governed by the transverse Rayleigh–Taylor instability. A regime map of the droplet breakup is produced, and the transitions between different regimes are obtained theoretically. The stretching liquid film during the droplet deformation and the fragment size distribution after droplet breakup are analysed quantitatively, and the results show that they are determined by the competition of breakup at different stages affected by the shear. Finally, the effect of the droplet viscosity is investigated, and the viscosity inhibits the droplet breakup in a strong shear airflow.

Wake of a Coaxial Corotating Rotor in Hover

A recent paper by Tinney and Valdez (AIAA Journal, Vol. 58, No. 4, 2020, pp. 1657–1667) reports the trade space between near-field acoustics and thrust produced by a laboratory-scale, coaxial, corotating rotor in hover by considering the effect of various index angles and stacking distances between the upper and lower rotor for a range of rotor speeds. The current effort is a follow-up campaign employing high-speed digital schlieren and single camera particle image velocimetry to measure the flowfield produced by the same stacked rotor. Particle image velocimetry measurements quantify the evolutionary behavior of the upper and lower blade tip vortices, and their interactions for various index angles and wake ages for a given rotor speed. Vortex tracking methods quantify the anisotropic wandering motions of the blade tip vortices and reveal patterns that are unique to both the upper and lower rotors. The findings reinforce the notion that the optimal index angle for the thrust produced by a coaxial, corotating rotor is one where the blade tip vortices produced by the upper rotor graze the low-pressure side of the lower rotor. If the miss distance is too small, collisions between the upper rotor vortex and the lower rotor ensue so that any gains in thrust are compounded by blade-vortex-interaction noise penalties.

Knifefish turning control and hydrodynamics during forward swimming.

Rapid turning and swimming contribute to ecologically important behaviors in fishes such as predator avoidance, prey capture, mating and the navigation of complex environments. For riverine species, such as knifefishes, turning behaviors may also be important for navigating locomotive perturbations caused by turbulent flows. Most research on fish maneuvering focuses on fish with traditional fin and body morphologies, which primarily use body bending and the pectoral fins during turning. However, it is uncertain how fishes with uncommon morphologies are able to achieve sudden and controllable turns. Here, we studied the turning performance and the turning hydrodynamics of the black ghost knifefish (Apteronotus albifrons, N=6) which has an atypical elongated ribbon fin. Fish were filmed while swimming forward at ∼2 body lengthss-1 and feeding from a fixed feeder (control) and an oscillating feeder (75 Hz) at two different amplitudes. 3D kinematic analysis of the body revealed the highest pitch angles and lowest body bending coefficients during steady swimming. Low pitch angle, high maximum yaw angles and large body bending coefficients were characteristic of small and large turns. Asynchrony in pectoral fin use was low during turning; however, ribbon fin wavelength, frequency and wave speed were greatest during large turns. Digital particle image velocimetry (DPIV) showed larger counter-rotating vortex pairs produced during turning by the ribbon fin in comparison to vortices rotating in the same direction during steady swimming. Our results highlight the ribbon fin's role in controlled rapid turning through modulation of wavelength, frequency and wave speed.

Investigating Shear-Layer Instabilities in Supersonic Impinging Jets Using Dual-Time Particle Image Velocimetry

Flow unsteadiness in supersonic impinging jets due to the aeroacoustic feedback can lead to practical problems like ground erosion in short takeoff and vertical landing aircraft, high noise levels, and high unsteady structural loading. The shear-layer instabilities of the jet play an important role in the flow dynamics. A full study of these instabilities requires time-resolved measurements of the flow velocity field. However, experimentally obtaining time-resolved velocity fields, derived from particle image velocimetry (PIV) techniques, has its challenges in high-speed flow applications due to the simultaneous requirement of high spatial and temporal resolution. A novel approach is presented in this paper, which uses time-unresolved dual-time digital PIV coupled with dynamic mode decomposition (DMD) analysis (DT–DPIV–DMD) of the velocity field pairs and applies it to study the dynamics of the shear-layer instabilities in supersonic impinging jets. DT–DPIV–DMD involves the acquisition of a pair of instantaneous velocity fields separated by a small time delay using two covisual PIV systems. The time delay must be sufficiently small to provide the necessary bandwidth to capture all the relevant dynamics of the flow being investigated. This is followed by DMD analysis of all acquired digital PIV velocity field pairs. A large-eddy simulation of an underexpanded impinging jet at Reynolds number 60,000, with nozzle-to-wall distance was first used to investigate the required measurement scales for the application of DT–DPIV–DMD. Using the optimum measurement scales, the technique was then experimentally demonstrated using DT–DPIV–DMD for two supersonic impinging jets cases and validated with acoustic measurements.

Centrifuge model studies on desiccation cracking behaviour of fiber-reinforced expansive clay

In this study, randomly distributed fiber reinforcement on the desiccation cracking behavior of expansive clay was investigated. Modeling considerations for the desiccation cracking behavior of unreinforced and fiber-reinforced clay was established using dimensional analysis. A custom-designed setup consisting of a specimen container, heating assembly, and digital image acquisition system was designed, calibrated, and used in the present study. A series of desiccation cracking tests were performed on unreinforced and fiber-reinforced expansive clay in a balanced beam geotechnical centrifuge. The test setup performance was evaluated by conducting tests at varying gravity levels and performing modeling of models. Digital image analysis and particle image velocimetry techniques were used to obtain qualitative information about the cracking of clay under the influence of fiber reinforcement and the varying thickness of the clay layers. The specimens reinforced with fibers exhibited improved cracking resistance than unreinforced clay specimens. The results indicate that the desiccation cracking of clays can be successfully modeled in a geotechnical centrifuge, highlighting the fact that this study is the first-ever such study. This knowledge can be used to study the behavior of critical geotechnical structures, especially clay barriers of landfill cover subjected to desiccation cracking.