Structure Of Fluid Research Articles

Ion association in hydrothermal aqueous NaCl solutions: implications for the microscopic structure of supercritical water.

Knowledge of the microscopic structure of fluids and changes thereof with pressure and temperature is important for the understanding of chemistry and geochemical processes. In this work we investigate the influence of sodium chloride on the hydrogen-bond network in aqueous solution up to supercritical conditions. A combination of in situ X-ray Raman scattering and ab initio molecular dynamics simulations is used to probe the oxygen K-edge of the alkali halide aqueous solution in order to obtain unique information about the oxygen's local coordination around the ions, e.g. solvation-shell structure and the influence of ion pairing. The measured spectra exhibit systematic temperature dependent changes, which are entirely reproduced by calculations on the basis of structural snapshots obtained via ab initio molecular dynamics simulations. Analysis of the simulated trajectories allowed us to extract detailed structural information. This combined analysis reveals a net destabilizing effect of the dissolved ions which is reduced with rising temperature. The observed increased formation of contact ion pairs and occurrence of larger polyatomic clusters at higher temperatures can be identified as a driving force behind the increasing structural similarity between the salt solution and pure water at elevated temperatures and pressures with drawback on the role of hydrogen bonding in the hot fluid. We discuss our findings in view of recent results on hot NaOH and HCl aqueous fluids and emphasize the importance of ion pairing in the interpretation of the microscopic structure of water.

Parallel time-stepping for fluid–structure interactions

We present a parallel time-stepping method for fluid–structure interactions. The interaction between the incompressible Navier-Stokes equations and a hyperelastic solid is formulated in a fully monolithic framework. Discretization in space is based on equal order finite element for all variables and a variant of the Crank-Nicolson scheme is used as second order time integrator. To accelerate the solution of the systems, we analyze a parallel-in time method. For different numerical test cases in 2d and in 3d we present the efficiency of the resulting solution approach. We also discuss some challenges and limitations that are connected to the special structure of fluid–structure interaction problem. In particular, we will investigate stability and dissipation effects of the time integration and their influence on the convergence of the parareal method. It turns out that especially processes based on an internal dynamics (e.g.driven by the vortex street around an elastic obstacle) cause great difficulties. Configurations however, which are driven by oscillatory problem data, are well-suited for parallel time stepping and allow for substantial speedups.

Hierarchical thermal transport in nanoconfined water.

The structure of nanoconfined fluids is particularly non-uniform owing to the wall interaction, resulting in the distinctive characteristic of thermal transport compared to bulk fluids. We present the molecular simulations on the thermal transport of water confined in nanochannels with a major investigation of its spatial distribution under the effects of wall interaction. The results show that the thermal conductivity of nanoconfined water is inhomogeneous and its layered distribution is very similar to the density profile. The layered thermal conductivity is the coupling result of inhomogeneous density and energy distributions that are generally diametrical, and their contributions to the thermal conductivity compensate with each other. However, the accumulative effect of water molecules is really dominating, resulting in a high thermal conductivity in the high-density layers with the low-energy molecules, and vice versa. Moreover, it is found that the adsorptive and repulsive interactions from solid walls have different roles in the hierarchical thermal transport in nanoconfined water. The adsorptive interaction is only responsible for the layered distribution of thermal conductivity, while the repulsive interaction is responsible for the overall thermal conductivity; accordingly, the thermal conductivity is independent of the strength of water-solid interactions. The identified hierarchical thermal transport in nanoconfined water and its underlying mechanisms have a great significance for the understanding of nanoscale thermal transport and even the mass and energy transport of nanoconfined fluids.

Dijet Acoplanarity in CUJET3 as a Probe of the Nonperturbative Color Structure of QCD Perfect Fluids

Using the CUJET3=DGLV+VISHNU jet-medium interaction framework, we show that dijet azimuthal acoplanarity in high energy A + A collisions is sensitive to possible non-perturbative enhancement of the jet transport coefficient, qˆ(T,E), in the QCD crossover temperature T ∼ 150–300 MeV range. With jet-medium couplings constrained by global RHIC& LHC χ2 fits to nuclear modification data on RAA(pT > 20) GeV, we compare predictions of the medium induced dijet transverse momentum squared, Qs2∼〈qˆL〉∼Δϕ2E2, in two models of the temperature, T, and jet energy E dependence of the jet medium transport coefficient, qˆ(T,E)). In one model, wQGP, the chromo degrees of freedom (dof) are approximated by a perturbative dielectric gas of quark and gluons dof. In the second model, sQGMP, we consider a nonperturbative partially confined semi-Quark-Gluon-Monopole-Plasma with emergent color magnetic dof constrained by lattice QCD data. Unlike the slow variation of the scaled jet transport coefficient, qˆwQGP/T3, the sQGMP model qˆsQGMP/T3 features a sharp maximum in the QCD confinement crossover T range. We show that the dijet path averaged medium induced azimuthal acoplanarity, Δϕ2, in sQGMP is robustly ∼ 2 times larger than in perturbative wQGP. even though the radiative energy loss in both models is very similar as needed to fit the same RAA data. Future A+A dijet acoplanarity measurements constrained together with single jet RAA and νn measurements therefore appears to be a promising strategy to search for possible signatures of critical opalescence like phenomena in the QCD confinement temperature range.

Machine for carrying works on deep loosening of soil with the simultaneous application of liquid organic fertilizers

The situation in the country is analyzed, the amount of fallow lands withdrawn from agricultural use during the period of reforms is estimated. The necessity of carrying out work on deep loosening of mineral soils of III-IV groups of heavy mechanical action to increase water permeability, in order to drain excess surface water into the underlying soil layers, has been substantiated. The ways of achieving a high-quality fine crumbly soil structure to achieve an optimal water-air balance for the subsequent development of plants have been investigated. The efforts of reclamation rippers are considered and a two-row deep-ripping type with front shanks of a volumetric structure and rear curved shanks with additional plowshares is selected. The possibility of simultaneous operations on deep loosening of the soil with the introduction of liquid fertilizers has been substantiated. This will increase the fertility of the soil and qualitatively change its composition. The rates of application of liquid fertilizers to the soil have been investigated and a modified design of the machine for the delivery of organo-containing liquid to an enlarged pore space has been proposed. The resistance of soil development was estimated, the traction and grip qualities of the machine were checked and the possibility of installing additional equipment for applying fertilizers to the root-inhabited vegetation layer was revealed. The movement of an organic fluid in the pore representation is considered, the possibility of creating a homogeneous soil structure and uniform distribution of fluid, organic matter, in the root zone of plants is analyzed. The influence of the ongoing reclamation measures on increasing soil fertility, creating an optimal water and air balance for the growth and development of cultural and expected increase in yield is analyzed.

Composition and geographic variation of the bacterial microbiota associated with the coelomic fluid of the sea urchin Paracentrotus lividus

In the present work, culture-based and culture-independent investigations were performed to determine the microbiota structure of the coelomic fluid of Mediterranean sea urchin Paracentrotus lividus individuals collected from two distinct geographical sites neighboring a high-density population bay and a nature reserve, respectively. Next Generation Sequencing analysis of 16S rRNA gene (rDNA) showed that members of the Proteobacteria, Bacteroidetes and Fusobacteria phyla, which have been previously reported to be commonly retrieved from marine invertebrates, dominate the overall population of microorganisms colonizing this liquid tissue, with minority bacterial genera exhibiting remarkable differences among individuals. Our results showed that there is a correlation between microbiota structure and geographical location of the echinoderm collection site, highlighting over-representation of metagenomic functions related to amino acid and bioactive peptides metabolism in specimens inhabiting the nature reserve. Finally, we also described the developmental delay and aberrations exhibited by sea urchin embryos exposed to distinct bacterial isolates, and showed that these defects rely upon hydrophilic compound(s) synthesized by the bacterial strains assayed. Altogether, our findings lay the groundwork to decipher the relationships of bacteria with sea urchins in their aquatic environment, also providing an additional layer of information to understand the biological roles of the coelomic fluid.

Effect of Micropore Structure on Macroscopic Water Cut Changing Law in Strongly Heterogeneous Reservoirs

Reservoir rock type (RRT) classification is commonly used for the fine characterization of strongly heterogeneous reservoirs. Many research focused on proposing different RRT methods, while few studies focused on the relationship between micropore structure and macroscopic seepage law of fluid transporting through different types of formation. Considering the different diagenesis degrees of rock types in different sedimentary facies, the quadrant unit method and FZI method were applied to classify and evaluate the strongly heterogeneous reservoirs. The corresponding capillary pressure curves and relative permeability curves for different rock types could be obtained. A set of theoretical models that could describe the macroscopic seepage law are proposed, and numerical simulation case studies were carried out to explore the superimposed seepage law in reservoirs under different degrees of heterogeneity. Results show that water cut rises faster in poor-property RRT formation than in good-property RRT formation, with a lower recovery factor under the same conditions. The water cut rising rate increases firstly and then decreases with water cut and recovery degree increasing. The poorer the rock property is, the earlier and higher the peak value of water cut rising rate is. Also, based on numerical simulation case studies, the superimposed seepage law is close to that in the poor-property formation as the heterogeneity degree strengthens. The newly proposed method not only could provide a reference for rock type classification based on micropore structure but also could expound the influence of micropore structure on the change law of macroscopic water cut and elaborates the macroscopic change law after the superposition of different types of reservoirs. The conventional normalization of relative permeability curves is only applicable to relatively homogeneous reservoirs and not applicable to strongly heterogeneous reservoirs, especially when the permeability variation is higher than 0.7. The newly proposed approach is capable of analyzing the effect of micropore structure on macroscopic seepage law and improving the prediction accuracy of the production profile.

Existence of global weak solutions for the high frequency and small displacement oscillation fluid–structure interaction systems

The purpose of this paper is to study the fluid–structure interaction (FSI) problem which is a simplified model to describe high frequency and small displacement oscillation of elastic structure in fluids. The elastic structure displacement is modeled by a fourth‐order nonlinear hyperbolic square equations, the motion of fluid is modeled by the time‐dependent incompressible Navier–Stokes equations. We prove the existence of at least one weak solution (global in time) to this problem by compactness method. The result both holds for two‐dimensional and three‐dimensional cases.

Influence of gas aggregation on water-solid interface: molecular simulation

ABSTRACT In this study, we conducted a series of molecular dynamics simulations of gas accumulation on homogeneous graphite substrates with a focus on the structure of fluid in the region near the substrate. The fluid density distribution revealed that epitaxial layers and gas enrichment layer arise from the adsorption of fluid particles on solids. Our analysis suggests that interfacial gas molecules transform into a liquid-like state and water molecules tend to cluster within the thin region adjacent to the substrate as the strength of gas–solid interaction increases. We then calculated the argon-water interfacial tension using three different methods: the Young-Laplace equation, direct integration method, and force balance method. Our analysis suggests that higher pressure within the gaseous domain tends to reduce tension at the curved argon-water interface. Although widely adopted to describe tension at gas–liquid interfaces, our results indicate that Bakker's equation is not necessarily suitable for the calculation of tension at fluid-solid interfaces. Our results indicate that fluid-solid interfacial properties and the morphology of the gaseous domain are influenced by the liquid-like epitaxial gas layer and gas enrichment layer, which could be attributed to the highly energetic nature of gas molecules and the tendency of gasses to adsorb on solids.

Hybrid force/position control for quasi continuum manipulators

Abstract The inherent compliant and safe structure of fluid driven continuum manipulators makes them a promising solution for various tasks. Despite their cheap production costs these robots have yet not found their way into industrial applications. This is due to the lack of precise models as well as control strategies which are both open fields of research. A basic industrial task is to control the force the manipulator exerts at its tool center point on a given object. In this work we present a hybrid force/position controller (HFPC) for the Bionic Soft Arm (BSA). It is assumed that contact is only established at the tool center point where the contact force can be measured. Further, we show how to extend the basic HFPC approach in order to overcome model inaccuracies. Experimental results are provided for the BSA where the HFPC is incorporated into an existing structure.

Review of nanofluids as coolant in metal cutting operations

One of the major problems arrive during machining processes is increased heat at the cutting area. Maximized heat the interface of the tool-work can affect failure in the tools used for cutting by the generation of micro-level cracks. To escape from this, the way which drastically comes to our mind is the usage of fluids behind the cutting processes. Nanofluid are some of the several innovative inventions in the subject of Nanotechnology. These Nanofluids will be having the structure of fluids that are produced with the suspension in nanoparticles. (1–100 nm) with inside a base fluid. For increasing the properties of thermophysical, our base fluid is implemented for targeted work. With the help of above literature research, we can come to a point where Nanofluid has the benefit of increasing the properties of thermophysical when estimated to other types of fluids within the same benefits with a good output from the reactions occurred in metal removing criteria. Further, we still want the way of production in a standardized format, a clear calculated percentage value of volume needed to be added in our base fluid, size of the nanoparticle and their benefits. We, also discuss some current analytical tests carried on the implementation of Nanofluids as a lubricant in machining processes.

Investigation of the relationship between nanochannel width and mass transfer characteristics for dense methane nanofluidics

In this paper, we analytically investigate the influence of the nanochannel width on mass transfer characteristics through the rough nanochannel by using non–equilibrium multiscale molecular dynamics simulation. The mass transfer characteristics are analyzed by fitting the curve correlation between the diffusion coefficient and nanochannel width. The diffusion coefficient is calculated using the revised Green–Kubo relation in different nanochannels. The numerical results demonstrate that the relationship between diffusion coefficient and the inverse of nanochannel width is parabolic. Moreover, the diffusion coefficients show significant variations in the small rough nanochannel, and gradually approach the values of bulk system with increasing the width of nanochannel. In addition, to explore its mechanism, the local atom number density, velocity profile, velocity autocorrelation function, the escape rate of molecule, local diffusion coefficient and projection radial distribution function are given in different widths of nanochannel under given boundary condition. Simulation results show that the local structure and number density of fluid influence the transfer mass characteristics. These results of this work may be conducive to further understand the mass transfer behaviors of nanofluidics, and guide the optimal design of nano–devices.

Twin-driven actuator with multi-layered disc magnetorheological fluid clutches for haptics

Magnetorheological fluids are composite materials made of ferromagnetic particles, medium oils, and several types of additives. We have developed actuation systems for the fine haptic control of master–slave robots. In this study, we proposed a new structure of a magnetorheological fluid–based actuator suitable for haptic devices. For the basic structure of the actuator, we proposed a twin-driven magnetorheological fluid actuator using two multi-layered disc-type magnetorheological fluid clutches for haptics. We conducted performance measures for the magnetorheological fluid clutches for haptics with three commercially available magnetorheological fluids (i.e. 122EG, 132DG, and 140CG from Lord Corp.). The experimental results show that 132DG is a better material for force control. Then, we proposed two types of twin-driven magnetorheological fluid actuators (i.e. link type and belt type) and compared their performance. The results show that the averages of the time constant are 19.1 and 16.1 ms for the link type and belt type, respectively. Furthermore, the averages of torque error are 0.033 and 0.068 N m for the link type and belt type, respectively. However, the belt-type twin-driven magnetorheological fluid actuator is better if a large range of motion is required, while the link-type twin-driven magnetorheological fluid actuator is better if accurate torque control is required.

Interaction between a falling sphere and the structure of a non-Newtonian yield-stress fluid

We present an experimental study using mixtures of aqueous superabsorbent polymers (SAP) where we systematically investigate the influence of the size of grains that make up the fluid structure on the mixture effective rheology and its domain of validity. In water, SAP powder grains can swell up to 200 times and form gel grains, dg, whose sizes (typically between 1 and 8 mm) can be controlled by choosing the size of the initial powder grains. The rheology of this mixture (water and touching grains) combines viscous, elastic and plastic aspects. Here, they are characterized using the free-fall of spheres of different densities and diameters (ds). The latter were varied between 3 and 30 mm, therefore providing a range where they become comparable to the fluid gel grains.We observe five different regimes of motion: (1) A linear regime where the sphere has a rapid and straight fall and reaches a constant terminal velocity. (2) An irregular regime where the sphere’s velocity varies around a constant value. (3) An intermittent regime where periods of no-motion and periods of irregular falls follow one another. (4) A slow fall regime where the sphere’s speed progressively decreases in a logarithmic way. (5) A no-motion regime when spheres are not heavy enough to overcome the yield stress of the mixture, or are too small compared to the grain size.The sphere trajectories in regimes (1), (2) and (3) are all following a same trend which, in the framework of a Herschel–Bulkley fluid, allows to estimate the effective yield stress σY and consistency Kv of the SAP mixtures. Both σY and Kv increase with increasing gel grain size. Regimes (2) and (3) are due to the interactions between the falling sphere and individual gel grains, i.e. the fluid structure. Moreover, the critical Yield number (Yc, which compares σY to the stress induced by the sphere’s net weight in the fluid) above which there is no motion decreases as ds∕dg becomes smaller than 2. So although the characteristic size of the fluid structure influences the magnitude of its rheological properties, the use of a Herschel–Bulkley rheology to describe the trajectories of the spheres breaks down only when the sphere diameter becomes very close to the SAP structure size.

Hydrodynamic driven dissolution in porous media with embedded cavities

Hydrodynamics characterization and analysis is an essential part in studying mineral dissolution in porous media with complex heterogeneous pore structures including embedded cavities. Cavities affect the pore-scale pressure and flow distribution in the surrounding porous matrix. Transport of the dissolved solute, concentration gradient, and thermodynamic driving forces in that area will be affected as a result of local flow features. Given the properties of cavities and porous media, vorticities may form, and the cavity may partially or fully contribute to the overall flow. Depending on the shape and alignment of the cavity with respect to the direction of general flow, fluid flow will be focused at certain locations on the cavity boundary. Reaction hotspots can form as a result of the facilitated mineral dissolution at those locations. A rigorous flow modeling approach that preserves the flow features inside the cavity and in the porous matrix is used. Stokes flow and seepage flow are applied as two different physics governing the fluid flow in a fluid-filled cavity and a highly permeable sediment-filled cavity consecutively. The analytical model framework permits capturing the detailed flow structure of a single-phase fluid at the curved interface of a prolate spheroidal cavity. The solutions for flow are used within a fully coupled, fully implicit reactive transport simulator to investigate the mineral dissolution in the porous host matrix. The cavity aspect ratio and slip parameter at the border are investigated as the two parameters that affect the dissolution. The simulation results showed that the reaction hotspots are mainly located on the border of the cavity where the influent enters and leaves the cavity. The midpoint between them is where the minimum mineral dissolution was placed. Approximating the cavity as a highly permeable sediment-filled porous zone showed a higher effective reaction rate compared to the fluid-filled cavity. The cavity aspect ratio showed to have a significant impact on the effective reaction rate of the investigated cases. The cavities with a shape closer to a sphere show a higher effective reaction rate.

Classifying diamagnetic states of plasma near Schwarzschild event horizon: Local approximation

We study the equilibrium magnetic field structure of relativistic hot fluid near the Schwarzschild black hole under the local approximation of background spacetime. The ratio between gravity modified Lagrange multiplier α0μ and characteristic skin depth λf turns out to be the determinant feature of the diamagnetic content in plasma. Plasmas near Schwarzschild event horizon show perfectly diamagnetic behavior, a state of zero generalized vorticity and helicity, when the ratio is zero and transitions into a non-diamagnetic state at a critical value of 2. The local approximation, in which space is cartesian, facilitates us to compare the result with its classical counterpart, and we find that the classical plasma decorrelation length μ (normalized to the skin depth) is stretched for smaller values of α0. Also, the skin depth of the charged fluid can vary with temperature which is absent in classical plasma.

In Ukrainian

These studies are aimed on the development of bioactive complex glass-ceramic calcium-phosphate-silicate materials, which are characterized by a reduced fusion with bone tissue in vivo. The aim of this work is to determine the effect of the level of resorption of complex calcium-phosphate-silicate materials and free surface energy on the nature of their binding to albumin in vitro. The calcium ion yield from the material after exposure to distilled water, after one, five, and 15 days, and after exposure in 10 % -albumin solution, after 5 days, was carried out by flame atomic absorption spectrometry using an Agilent AA 240FS device.The surface microrelief was evaluated by the average mean of the profile (R a ) and determined using a Surtronic 3+ profilometer. The value of the free energy of the surface for complex materials was determined after exposure to albumin by the Owens-Wendt-Rabel-Kaelble method. Histological examinations were performed using an Olympus BX63 light microscope. The structure of cells and intercellular fluid was recorded using a digital camera DP73 (Olympus) and software “Cell Sens Dimention 1.8.1”. Samples of the femur of rats, 30 days after implant implantation, which was made of the developed glass-ceramic material, were stained with Weigertpicro-fuchsin and eosin, Van Giesonpicro-fuchsin. To obtain the initial model glasses, the R 2 О–CaF 2 –RO–RO 2 –R 2 O 3 –R 2 O 5 –MoO 3 –SiO 2 system was selected as the basis of glass-ceramic materials, and 5 compositions were synthesized at the temperature of 1250÷1350 °С. To obtain combined glass-ceramic materials, model glass powders were used with addition of 5 wt. % (per 100 wt. % model glass) yttrium stabilized zirconia (DTS 1). The powders were pressed using carboxymethyl cellulose as a binder and fired at 750÷800 °C for 15 minutes. The samples obtained were characterized by the presence of hydroxyapatite crystals in an amount of 50÷60 vol. %. The solubility of the developed materials in water is determined by the properties of the glass-phase (the degree of silicon-oxygen skeleton bonding) and the hydroxyapatite content has been found. The process of binding calcium to albumin (the mass fraction of bound calcium in a solution of 15.67 mg/dm 3 ) for the developed materials is determined by the characteristics of the surface of the materials (FSE = 74.6 mJ/m 2 , R a = 3.4 mcm), the features of their structure (f Si = 0.28, the number of HA crystals = 60 vol. %, with a crystal size of 1.0 μm) and the nature of dissolution. An in vivo study of the samples confirmed the possibility of creating biocompatible materials with a reduced splicing time with bone tissue. As a result of an experimental study using histological methods, it has been determined that the ASZ-5 material is biocompatible, characterized by osteoinductive and osteoconductive properties.

Efficacy of nanosecond laser treatment in central serous chorioretinopathy with and without atrophy of retinal pigment epithelium

BackgroundTo evaluate the outcomes of subthreshold nanosecond laser treatment of chronic central serous chorioretinopathy (CSC) as a function of the severity of concomitant of retinal pigment epithelium (RPE) defects.MethodsThis retrospective study compares data from 23 CSC diagnosed eyes with only mild RPE defects (group 1), 16 CSC eyes with moderate RPE defects (group 2), and 17 CSC eyes having severe RPE defects (group 3). After subthreshold treatment with the standard Ellex 2RT™ nanosecond laser (Ellex Medical Lasers Ltd, Australia), changes in macular structure and levels of subretinal fluid (SRF) were assessed by OCT-SD, OCT-A, functional integrity of the retina was assessed by corrected distance visual acuity (CDVA) and microperimetry, each at baseline and 1, 3, 6, and 12 months after initial treatment; re-treatment took place in cases of persistent SRF pro re nata.ResultsDuring the 12 months observation period, group 1 and 2 mostly required on initial and one re-treatment (1.9 ± 1.0 treatments; 1.9 ± 1.3 treatments). In contrast, group 3 was subject to three to four treatments (3.7 ± 1.5 treatments). 6 to 12 months after treatment, subretinal fluid (SRF) disappeared in 100% of the eyes of group 1 and in 76.9%, and 42.9% of the eyes of group 2 and group 3, respectively. Retinal sensitivity and CDVA improved in group 1 and 2, but did not change significantly in group 3 during the 12 months period.ConclusionsSubthreshold nanosecond laser treatment is an effective and safe method for the restoration of macular anatomy and sensitivity in acute and chronic CSC cases with only mild or moderate RPE defects. However, this laser treatment has very limited outcome in CSC eyes with more severe RPE defects.

Investigation of thermal treatment of hybrid nanoparticles in a domain with different permeabilities

Porous domain filled with nanoliquid was scrutinized in the current article. Magnetic force and permeability were considered as main effective variables, and their influences were involved in momentum. Also, energy equation has a source term related to radiation. Outputs were achieved with CVFEM simulation. As permeability augments, forces against the flow decline. So, stronger eddy appears and temperature gradient augments. Structure of fluid gets affected more significantly by Ha when permeability increases. Nu increases by increments of Da related to greater velocity of nanomaterial, and similar tendency for Nu has been reported with rise of Ra. With intensification of Ha, Nu reduces because of lower distortion of isotherms. The adverse impact of Lorentz force reduces when radiation impact is neglected.

Multi-fracture interactions during two-phase flow of oil and water in deformable tight sandstone oil reservoirs

Tight oil reservoirs are complex geological materials composed of solid matrix, pore structure, and mixed multiple phases of fluids, particularly for oil reservoirs suffering from high content of in situ pressurized water found in China. In this regard, a coupled model considering two-phase flow of oil and water, as well as deformation and damage evolution of porous media, is proposed and validated using associated results, including the oil depletion process, analytical solution of stress shadow effect, and physical experiments on multi-fracture interactions and fracture propagation in unsaturated seepage fields. Then, the proposed model is used to study the behavior of multi-fracture interactions in an unsaturated reservoir in presence of water and oil. The results show that conspicuous interactions exist among multiple induced fractures. Interaction behavior varies from extracted geological profiles of the reservoir due to in situ stress anisotropy. The differential pressures of water and that of oil in different regions of reservoir affect interactions and trajectories of multi-fractures to a considerable degree. The absolute value of reservoir average pressure is a dominant factor affecting fracture interactions and in favor of enhancing fracture network complexity. In addition, difference of reservoir average pressures in different regions of reservoir would promote the fracturing effectiveness. Factors affecting fracture interactions and reservoir treatment effectiveness are quantitatively estimated through stimulated reservoir area. This study confirms the significance of incorporating the two-phase flow process in analyses of multi-fracture interactions and fracture trajectory predictions during tight sandstone oil reservoir developments.