Fluid In Channel Research Articles

Geology and exploration indications of the lithocap in Qianpu area, Luzong Basin, Anhui

The lithocap is a large-scale alteration including silicification, advanced argillic and argillic that developed near the surface by hydrothermal activities. It is helpful for exploring high-sulfidation epithermal deposits and porphyry deposits in its root and deep parts, respectively, and is used as a new prospecting indicator. There are many minerals in the lithocap and it is difficult to identify them; alunite is the most representative mineral and one of the new minerals used to guide exploration; it plays an important role in assessing the metallogenic potential and guiding ore prospecting. The Luzong basin is dominated by iron oxide apatite deposits (IOAs). In recent years, many researchers have been searching for porphyry copper–gold deposits and epithermal deposits as studies on alunite and lithocaps in the basin have gradually been undertaken. In field explorations and investigations of the Luzong basin, the author found that in Qianpu area of the central basin, where kaolinite deposits were mainly explored in the past, Well-occurring alunite minerals and advanced argillic alterations have developed. A typical lithocap developed in Qianpu area after a series work of geology and mineralogy, such as alteration mineral species, alteration types, and alteration zoning, which were formed by the hydrothermal alteration of the volcanic rocks of the Zhuanqiao Formation. The minerals in this lithocap are mainly quartz, alunite (including aluminum-phosphate-sulfate, APS), pyrite, zunyite, dickite, pyrophyllite, kaolinite, and a small amount of illite, which are present sequentially from the center to the peripheral quartz-alunite-pyrite alteration, alunite-dickite alteration, dickite-pyrophyllite alteration, alunite-kaolinite-illite alteration, and alunite veins superimposed on quartz-alunite-pyrite alteration and alunite-dickite alteration. Three types of alunite were produced in large quantities and were formed in three kinds of environments. The I-type alunite, which was formed by hydrothermal metasomatism alteration in the early stage and is densely disseminated distribution, coexisting with quartz and pyrite, is a magmatic hydrothermal alunite. Relatively pure alunite veins (II-alunite) of varying thicknesses formed in the open space in the mid-hydrothermal period in a magmatic steam environment. The fine-grained III-alunite that coexists with kaolinite formed in the late hydrothermal period and in a steam-heated environment. The alunite produced by various origins represents multiphase hydrothermal activity in the Yanshanian period in the Qianpu area; the Na content decreased, the K and Pb content increased, and the K/Na molar ratios ranged from 2.82 to 6.58 (EPMA) and 1.59 to 3.93 (LA-ICP MS) from the early to middle and late hydrothermal stages, indicating that the formation temperatures were more than 200 °C and gradually decreased with hydrothermal evolution. There is a high-sulfidation epithermal system in Qianpu area. In combination with the specific environmental significance of zunyite indicating a high temperature and closeness to the fluid channel, as well as the characteristics and genesis of the Huangzhuyuan silver polymetallic deposit near Qianpu, it is inferred that the Qianpu-Huangzhuyuan area has prospecting potential for porphyry-epithermal deposits.

Machine learning-assisted high precision predictive modelling of convective heat transfer in fluid channels fabricated by laser powder bed fusion

Laser powder bed fusion (LPBF) has proven to be an effective tool in fabricating heat transfer devices with improved efficiency. However, the accurate prediction of convective heat transfer in LPBF-fabricated fluid channels remains a challenge. The classical Gnielinski model is regarded as the most accurate correlation for predicting forced convective heat transfer in traditional pipes. However, whether it is applicable to LPBF-fabricated pipes is yet to be determined. To address this challenge, in this study, pipe samples with diameters of 3 mm, 4 mm, and 5 mm were designed and fabricated using LPBF along the building angles of 0°, 45°, and 90°. The pressure loss and heat transfer characteristics of these samples were experimentally measured. Results showed that there was a maximum prediction error of 72.1 % between the classical Gnielinski model and experimental results. To improve the prediction accuracy, a corrected Colebrook model with improved prediction accuracy of the friction factor was developed, introduced into the classical Gnielinski model, and reduced the maximum prediction error down to 36.8 %. To further improve the prediction accuracy, a gradient descent-based machine learning method was adopted to reconstruct the Gnielinski model, which achieved a high prediction accuracy with prediction errors of below 10 %. With the assistance of machine learning, a high precision predictive model of convective heat transfer in LPBF-fabricated fluid channels was established.

Fabrication of angstrom-scale two-dimensional channels for mass transport.

Fluidic channels at atomic scales regulate cellular trafficking and molecular filtration across membranes, and thus play crucial roles in the functioning of living systems. However, constructing synthetic channels experimentally at these scales has been a significant challenge due to the limitations in nanofabrication techniques and the surface roughness of the commonly used materials. Angstrom (Å)-scale slit-like channels overcome such challenges as these are made with precise control over their dimensions and can be used to study the fluidic properties of gases, ions and water at unprecedented scales. Here we provide a detailed fabrication method of the two-dimensional Å-scale channel devices that can be assembled to contain a desired number of channels, a single channel or up to hundreds of channels, made with atomic-scale precision using layered crystals. The procedure includes the fabrication of the substrate, flake, spacer layer, flake transfers, van der Waals assembly and postprocessing. We further explain how to perform molecular transport measurements with the Å-channels to directly probe the intriguing and anomalous phenomena that help shed light on the physics governing ultra-confined transport. The procedure requires a total of 1-2 weeks for the fabrication of the two-dimensional channel device and is suitable for users with prior experience in clean room working environments and nanofabrication.

Micro "Hyper-Channels" on Laser-Refined Cellulose Structures.

Controlled liquid transportation is widely applied in both academia and industry. However, liquid transport applications are limited by parameters such as driving forces, precision, and velocity. Herein, a simple laser-refining technology is presented to produce micro "hyper-channels". A cellulose substrate is rendered hydrophobic through silanization and refined with a laser to produce both hierarchical nanostructures and a wettability contrast simultaneously. Such a method enables faster ("hyper"-channel) aqueous liquid transportation (≈25X, 50mms-1 ) compared to conventional methods. Complex patterns can be readily produced at different scales with spatial resolution as low as 50µm. This technique also controls the refining depth on the thin paper substrate. Shallow channels can be fabricated on thin paper substrates that enable fluidic channel-crossover without liquid mixing. With certain parameters, the technique creates "portals" through the substrate, allowing trans-dimensional liquid transportation between two layers of a single sheet of substrate. The fluid throughput can be increased, while also permitting fluidic channel crossover without liquid mixing. By introducing multiple portals, the controlled fluid can transfer trans-dimensionally several times, enabling further fluidic complexity. The real-life utility of the method is demonstrated by creating a trans-dimensional microfluidic device for colorimetric detection.

Kinetics of suspended particles with different shapes interacting in a fluid channel

Kinetics of suspended particles with different shapes interacting in a fluid channel

Performance investigation of a hybrid PV/T collector with a novel trapezoidal fluid channel

The photovoltaic-thermal collector (PV/T) is an innovative technology that combines PV cells and solar thermal collectors into a co-generation unit, enabling full-spectrum solar utilization. This research proposes and examines a hybrid PV/T system with novel trapezoidal fluid channels embedded in graphite, arranged in a parallel S-shaped structure under outdoor conditions of Beijing. Parametric discussions and daily performance analysis are conducted to assess its effectiveness and stability. A daily average of 12.7 °C reduction in cell temperature compared to PV modules results in a relative 5.20 % improvement in electrical output under the intensity of solar radiation is 597 W/m2. Similarly, the peak temperature of the water tank reaches 56.9 °C, and thermal efficiency is enhanced by 7.86 % over conventional sheet-tube PV/T collectors. For further optimization, a constrained adaptive particle swarm optimization algorithm (EPF-APSO) is constructed based on the experimental data, implementing a variable water flow rate (VWV) strategy. Compared to a constant water flow rate (CWV), the overall energy collected varies from 2.755 to 2.828 kWh per day, potentially reducing pump energy consumption by 17.93 %. The contribution of this paper provides references on structural and operational parameters optimization of PV/T collectors applying machine learning algorithms for better comprehensive efficiency.

Analysis of non-linear losses in a parallel plate thermoacoustic stack

PurposeThis study aims to analyse the non-linear losses of a porous media (stack) composed by parallel plates and inserted in a resonator tube in oscillatory flows by proposing numerical correlations between pressure gradient and velocity.Design/methodology/approachThe numerical correlations origin from computational fluid dynamics simulations, conducted at the microscopic scale, in which three fluid channels representing the porous media are taken into account. More specifically, for a specific frequency and stack porosity, the oscillating pressure input is varied, and the velocity and the pressure-drop are post-processed in the frequency domain (Fast Fourier Transform analysis).FindingsIt emerges that the viscous component of pressure drop follows a quadratic trend with respect to velocity inside the stack, while the inertial component is linear also at high-velocity regimes. Furthermore, the non-linear coefficient b of the correlation ax + bx2 (related to the Forchheimer coefficient) is discovered to be dependent on frequency. The largest value of the b is found at low frequencies as the fluid particle displacement is comparable to the stack length. Furthermore, the lower the porosity the higher the Forchheimer term because the velocity gradients at the stack geometrical discontinuities are more pronounced.Originality/valueThe main novelty of this work is that, for the first time, non-linear losses of a parallel plate stack are investigated from a macroscopic point of view and summarised into a non-linear correlation, similar to the steady-state and well-known Darcy–Forchheimer law. The main difference is that it considers the frequency dependence of both Darcy and Forchheimer terms. The results can be used to enhance the analysis and design of thermoacoustic devices, which use the kind of stacks studied in the present work.

Study on the heat transfer enhancement characteristics by flow-induced vibration of inserting polyethylene membrane inside the channel

With the development of science and technology, the heat dissipation problem of high-density electronic products has gradually emerged in engineering practice. In this paper, the enhanced heat dissipation process of fluid induced oscillation through flexible membrane is proposed, which belongs to the multi-field synergistic bidirectional coupling effect of thermal-fluid-solid coupling. Through the comparative numerical analysis of the flow induced oscillation of the flexible membrane and the fixed rigid fin in the flow channel, the mechanism of the fluid induced oscillation of the flexible polyethylene membrane is revealed. Based on the two-way fluid-solid coupling method, a numerical model for the heat transfer process of polyethylene membrane with thickness of 0.02 mm in the fluid channel was established. The temperature field, Nu (Nusselt number) and PEC (Performance comparison index) number of the rigid fin and polyethylene membrane installed in the channel under different Reynolds numbers were calculated respectively. The ratio of the length of the membrane to the height of the channel was adjusted for multiple groups of calculations to verify the positive effect of the polyethylene membrane installed in the channel on the heat exchange effect. The results show that in the fully developed area of heat transfer, the channel with polyethylene membrane is better than that with rigid fins in terms of turbulence and vortex shedding; at Re = 4400, the comprehensive enhanced heat transfer factor of heat exchange is the largest, up to 1.27; as the ratio of the height of the new flexible membrane to the height of the channel is 1, the heat transfer enhancement effect is best. In the next step, the correlation theory between oscillation characterization parameters and heat transfer enhancement effect under pulsating fluid excitation will be investigated.

Performance simulation of novel heat pipe type phase change thermal storage device

Given that the performance of the phase change thermal storage device (PCTSD) is limited by the low thermal conductivity of the phase change material, more effective heat transfer structures should be developed to improve the thermal storage rate. In this paper, a novel micro heat pipe array (MHPA)–PCTSD with a highly rational heat transfer structure is proposed to understand the influence mechanism of the relative positions of the MHPA and heat transfer channel. The arrangement of the heat transfer fluid (HTF) channels on both sides of the MHPA (Type A) and the arrangement of the MHPA on both sides of the HTF channel (Type B) are numerically modeled in three dimensions, and the thermal storage performance is analyzed. Results show that Type B has a significant advantage over the traditional heat pipe PCTSD and Type A, which can obtain better temperature uniformity and more reasonable thermal resistance distribution. Moreover, its total thermal resistance and melting time are 17.4% and 21% lower than those of Type A, thus confirming its higher optimization potential.

Gravitational settling of two impermeable semi-torus particles

This research aimed to numerically investigate the dynamics of two semi-torus particles using the Immersed Boundary (IB) method. Various initial configurations were considered: vertically aligned along the centre of the fluid channel (Case A), vertically aligned in an asymmetric location (Case B), and horizontally aligned symmetrically to the channel centreline (Case C). Additionally, the impact of different starting alignments on particle dynamics was explored. When the particles were dropped along the middle of the channel, their dynamics depended on the fluid viscosity. Higher viscosities led to drafting and kissing phases, while lower viscosities resulted in multiple cycles of drafting, kissing, and tumbling (DKT). Similarly, the dynamics of particles dropped from an asymmetric location were also influenced by viscosity. For horizontally aligned particles along the centreline, the obtained results agreed well with previous studies. Notably, the initial orientation of the particles had a significant effect on their behaviour, particularly in less viscous fluid conditions.

Effects of Joule heating and reaction mechanisms on couple stress fluid flow with peristalsis in the presence of a porous material through an inclined channel

Abstract The objective of this study is to assess the flow behavior of the peristalsis mechanism of a couple stress fluid in incorporating a porous material. In addition, reaction mechanism and Ohmic heating are also taken into consideration with slip boundary conditions. For the purposes of mathematical simulation, we assume a long-wavelength approximation, ignoring the wave number and taking a low Reynolds number into account. The obtained outcome is shown in a graphical manner and then analyzed. The results of this investigation reveal that when the Hartmann number improves, the pattern of velocity noticeably decelerates. The Lorentz forces have a retarding impact on the velocity of the fluid from a physical standpoint. As the couple stress variable rises, so does the velocity of the fluid. As the couple stress component increases, the skin friction coefficient increases in one region of the fluid channel and falls in another region, between x = 0.5 and x = 1. As the thermal slip variable rises, more heat is transferred through the surface to the fluid, resulting in a rise in the temperature profile. When the couple stress variable is raised, the Nusselt number rises, while the thermal radiation factor causes the Nusselt number to decline. The results showed a positive relationship between the Sherwood number and the reaction mechanism parameter. This study demonstrates the potential use of this research in the fields of a career in engineering, namely, in enhancing hydraulic systems, as well as in medicine, particularly in optimizing gastrointestinal processes. The process of dissection facilitates the unimpeded circulation of blood and lymph inside the vascular system of the body, enabling the delivery of oxygen to tissues and the elimination of waste materials.

Fluidic switch using an elastic actuator due to induced charge electro-osmosis combined with a natural convection pump

An integrated fluid circuit consisting of a pump and a fluidic switch is a basic unit in a microfluidic circuit. Here, we propose a fluidic switch using an elastic actuator due to an induced charge electro-osmosis (ICEO) combined with a natural convection (NC) pump and experimentally demonstrate the switching behavior between the two branch fluidic channels in a flow state generated by the NC pump. In particular, we experimentally demonstrate that the NC pump can generate a net flow of ∼0.2 mm s−1 in the circular channel having branch channels, and the ICEO fluidic switch can change the flow state between the branch channels within ∼3 s. Our prototype system should contribute to innovative microfluidic systems in the future.

CFD Simulation on the Effect of Adding Dimple Balls Stagger Position on Base Plate on the Performance of V-Corrugated Air Heating Solar Collector

The ever-increasing increase in energy consumption requires great attention. Therefore, efforts need to be made to find new energy sources, such as solar energy. The absorber plate absorbs solar energy in the form of radiation, and heat is transferred by convection to the working fluid through the solar collector. Increasing the thermal efficiency of the solar air collector by modifying the absorption area using a v-corrugated absorber and also increasing the convection heat transfer coefficient by creating turbulence in the heat transfer area. Flow turbulence can be achieved by providing a disturbance in the form of a dimple in the working fluid channel above the base plate. This research was conducted utilizing numerical simulations and experiments. CFD simulation aims to obtain the most optimum ratio of ΔT/ΔP values of diameter and dimple distance using ANSYS Fluent software with a diameter variation of 6mm, 8mm, 10mm, and 45mm spacing; 50mm, and 5mm. Based on the results of CFD simulations that have been carried out on each variation of the distance and diameter of the dimple, it can be concluded that the closer the distance between the dimples, the smaller the resulting pressure drop, and the larger the diameter of the dimple, the greater the resulting temperature value. The use of a larger dimple diameter results in an increase in the heat transfer area and further increases the outlet temperature. The expected ratio is the value of the largest temperature increase and the smallest pressure drop. In the calculation of the total ratio, the dimple diameter of 10 mm with a distance of 45 mm has the highest ΔT/ΔP ratio value.

Additive manufacturing of complex structures and flow channels using wire-arc thermal spray

The development of a cost-effective additive manufacturing method for millimeter-scale metal structures is essential for the fabrication of novel, high-efficiency heat exchangers and heat sinks. The millimeter-scale fluid channels produced by these structures provide a large surface area to promote heat transfer while minimizing system volume and mass. Traditional additive manufacturing methods are limited by their high cost, high energy consumption, and long processing times. This study presents an efficient additive manufacturing method by using wire-arc thermal spray through a polymer mask. Aluminum and copper structures with arbitrary shapes and a height of 1.3 mm were deposited on a plate 74 mm × 51 mm in size in 30 min and 15 min, respectively. Masks were fabricated by 3D-printing with a high-temperature photopolymer resin. All fabricated structures exhibited a dense center region, a porous side wall region, and a porous satellite particle region between deposited structures. The development of the deposited structures throughout the process is investigated for aluminum (having a low density, surface tension, and melting temperature) and copper (having a high density, surface tension, and melting temperature). The influence of the distance between the mask and the substrate on structure geometry and porosity is studied. The fabrication steps of a liquid-cooled mini-channel heat sink containing an enclosed flow channel are demonstrated using the proposed additive manufacturing method. The results suggest that using wire-arc thermal spray through a polymer mask can be used as a cost-efficient method to additively manufacture metal structures on the millimeter scale.

Lymphatic vessels accompanying dorsal and basal dural sinuses in the human brain

Recent investigations showed the presence of meningeal lymphatic vessels (mLVs) along the superior sagittal and transverse dural sinuses which drain both fluid and immune cells from the cerebrospinal fluid (CSF) to the deep cervical lymph nodes. This study uses immunohistochemistry (IHC) and the Western Blot technique to show the presence of mLV accompanying the dorsal (superior sagittal, inferior sagittal, transverse, sigmoid, and straight) and basal (cavernous, sphenoparietal, superior, and inferior petrosal) dural sinuses in the human brain. Samples for IHC were obtained from dorsal and basal meningeal dural sinuses of 3 human cadavers and 3 autopsies. Routine histological techniques were carried out for the specimens. Podoplanin (PDPN, lymphatic vessel endothelial cell marker) and CD31 (vascular endothelial cell marker) IHC staining were applied to the 5 µm thick paraffin sections. Furthermore, PDPN and CD31 protein expressions were evaluated using Western Blot to the tissue samples from the same regions of 4 autopsies. Two consecutive sections from each sinus were PDPN, and CD31 was stained to differentiate blood vessels (BV) from mLV. The IHC staining showed the presence of mLVs accompanying both dorsal and basal dural sinuses. The mLVs accompanying the dorsal dural sinuses had a larger dimensions range compared to the basal dural sinuses. However, the number of mLVs along the basal dural sinuses was more than the mLVs along the dorsal ones. Further, fluid channels were closely localized to the mLV, with varying diameters and densities. Western Blotting technique showed the presence of PDPN expression in both dorsal and basal dural sinus samples. The knowledge of the presence of mLV along both dorsal and basal dural sinuses in humans can increase the understanding of how mLV contributes to the brain lymphatic circulation and may help understand the neuropathophysiological processes of various neurological diseases.

Review and Analysis of Heat Transfer in Spacer-Filled Channels of Membrane Distillation Systems.

Membrane distillation (MD) is an attractive process for the concentration of seawater brines. Modelling and simulation of membrane distillation processes requires a better knowledge of the heat transfer coefficients in spacer-filled channels which are usually determined by applying empirical correlations for the Nusselt number. In this study, first, a comprehensive literature review on heat transfer correlations was conducted. It was found that the empirical correlations often used for MD simulation result in strongly varying Nusselt numbers that differ by up to an order of magnitude at low Reynolds numbers. Then, heat transfer in spacer-filled channels was investigated experimentally in a membrane distillation system using an aluminum plate instead of a flat-sheet membrane. Numerous tests were carried out with sodium chloride solutions in a wide range of salinities, between 1 g/kg and 95 g/kg, and temperatures, between 30 °C and 80 °C, yielding high heat transfer coefficients in a range of 1500 to 8300 W/(m2K) at relatively low Reynolds numbers, between 100 and 1500, clearly showing the influence of the spacers on heat transfer. A new empirical Nusselt correlation (Nu=0.158Re0.652Pr0.277) was derived which represents the experimental data with a deviation of 10% and is valid for 100<Re<1500 and 2<Pr<7. Computational fluid dynamics simulations were performed to analyze the variations of the fluid properties across the boundary layer due to temperature differences. The simulations showed only minor deviations of the heat transfer coefficients in the hot and cold fluid channels for small driving temperature differences.

Computational modeling and experiment validation of a microchannel cross-flow heat exchanger

Microchannel Cross-Flow Heat Exchanger (MCFHE) is one of the potential candidates to be employed in various energy recovery. Compared to microchannel counter-flow heat exchanger, little research has been devoted to simulating the heat transfer process inside a MCFHE. Given the complex temperature distributions associated with cross-flow heat exchangers, the conventional “unit cell” approach for a pair of fluid channels becomes invalid. In this study, a new methodology is developed to resolve the modeling challenges associated with a 2-pass MCFHE. Specifically, the MCFHE is divided into 10 zones to minimize mesh size associated with each fluid channel, which leads to a computationally efficient and segregated CFD model. The CFD model provides detailed temperature distributions within both fluid channels, and the resulted outlet temperatures match closely with the experimental data. In addition, the Nusselt numbers in the air and oil channels agree well with classical developing flow correlations. Using the ε−NTU method, it provides an initial guess for the mid-pass oil temperature that is needed to initiate the CFD simulations for the first pass including Zone 1–5. Furthermore, the resulted analytical results based on the iterative ε−NTU method match closely with the CFD simulations.

Acoustofluidics in an equilateral triangular channel

Acoustofluidics is of great interest in many fields, such as physics, biology, chemistry, medicine, and manufacturing. Numerous research has been conducted on the basic physics of acoustofluidics in common (e.g., rectangular and circular) fluid channels. Recently, it has been reported that the resonant acoustic field in a triangular channel can be applied for rapid acoustofluidic sedimentation of microparticles. In this paper, we examine in detail the fundamentals of acoustofluidics in triangular channels and show their potential for ultrasonic particle manipulation. The variations of acoustofluidic fields, including acoustic resonances, acoustic radiation force, and outer acoustic streaming, in an equilateral triangular channel are investigated both experimentally and numerically. We develop a generalized limiting velocity solution for predicting the outer acoustic streaming fields in triangular channels of arbitrary shape. We show that it can generate both symmetric and antisymmetric acoustic resonances in triangular channels, which lead to outer acoustic streaming fields that are similar or distinct to those seen in common fluid channels. Boundary vibration-dependent asymmetric standing wave profiles can typically be excited, where spatial separation of acoustic pressure and streaming patterns is observed, which is consistent with the recent prediction of acoustofluidics in asymmetric acoustic resonances. The results demonstrate the richness of acoustic resonances and boundary-driven acoustic streaming patterns that arise in standing acoustic wave fields and open perspectives for acoustomicrofluidic applications such as heat and mass transfer enhancement and dynamic manipulation of micro- and nanoparticles.

Inspired biomimetic design for efficient fluid channel configuration based on leaf vein structures

Efficiency of heat and mass transfer is critical for vapor chambers (VCs), but conventional designs often encounter problems with heat transfer and liquid distribution. The hierarchical branch network and heat dissipation function of leaf veins share certain similarities with the wick structure employed in vapor chambers (VCs). Therefore, to explore the potential of biomimetic design for optimizing fluid channel configuration, we investigated the heat transfer and capillary flow performance of symmetric and asymmetric leaf vein (SLV and ALV) networks. Our investigation reveals that the SLV exhibits the best heat transfer and flow characteristics among the ALV and tree branch structure. Additionally, the relationship between the distribution patterns and natural structures of leaf veins was also elucidated. Our findings suggest that the leaf vein network may offer a promising template for designing more efficient liquid channels in VCs and other engineering applications.

Observation of a Synchronicity between Shallow and Deep Seismic Activities during the Foreshock Crisis Preceding the Iquique Megathrust Earthquake

We analyze at a broad spatial scale the slab seismicity during one of the longest and best recorded foreshock sequence of a subduction earthquake to date: the M8.1 2014 Iquique earthquake in Chile. We observe the synchronisation of this sequence with seismic events occurring in the deep slab (depth ~100km). This synchronisation supports the existence of long-range seismic bursts already observed in the Japan Trench subduction. It suggests that, like for the 2011 Tohoku earthquake, the deep slab was involved in the nucleation process of the Iquique earthquake. We interpret these observations by the presence of pressure pulses propagating in transient fluid channels linking the deep slab where dehydration occurs to the shallow seismogenic zone before the earthquake. These observations may seem surprising but they are in line with the short-lived pulse-like channelized water escape from the dehydration zone predicted by recent studies in slab mineralogy and geochemistry.