Showing papers in "The International Journal of Multiphysics in 2020"
TL;DR: In this paper, a review of thermographic and vibrothermography applications such as cold climate operations, determine the temperature profile of steel samples under tensile testing and perform composites Non-Destructive Testing (NDT).
Abstract: The paper reviews thermographic and vibrothermography applications such as cold climate operations, determine the temperature profile of steel samples under tensile testing and perform composites Non-Destructive Testing (NDT). This review paper discusses studies, where IR thermography has been used effectively in research and development projects at the UiT The Arctic University of Norway and AGH UST. The applications discussed in this work are to determine:
Thermal conductivity and heat transfer coefficient of freshwater and marine ice
An industrial solution for detecting icing
Relative required insulation (IREQ) of apparels
Variation of tensile strength and surface temperature of steel samples under tensile testing under cold temperatures
Vibrothermography for Non-Destructive Testing (NDT) of composites
9 citations
TL;DR: In this paper, the low-velocity impact resistance of carbon fiber reinforced polymer (CFRP) woven composite was investigated with the help of Charpy impact tests, and the experimental results indicated about 10% drop in energy-absorbing capability of CFRP samples at low temperatures in comparison to room temperature.
Abstract: Carbon Fiber Reinforced Polymer (CFRP) composites have emerged as a major class of structural materials that have a significant potential use as a substitute for metals in aerospace, marine, automotive, and architecture due to their higher-strength-to-weight-ratio CFRP is well suited for various applications, but their mechanical properties such as ‘low-velocity impact resistance’ are not well studied In this study, the low-velocity impact resistance of CFRP woven composite was investigated with the help of Charpy impact tests The CFRP samples were tested at room temperature (22°C) and at low temperature (-20°C) The experimental results indicated about 10% drop in energy-absorbing capability of CFRP samples at low temperatures in comparison to room temperature The experimental results obtained for the room temperature were validated through finite element simulations using ANSYS® Workbench Explicit Dynamics The mesh sensitivity analysis was performed to improve the accuracy of the finite element model The numerical results helped to narrow down on the CFRP material properties that changed with temperature drop It was found at -20°C, orthotropic Elasticity (Young’s moduli in three mutually perpendicular directions) increases for CFRP woven composite as compared to room temperature (22°C), however the CFRP become brittle and there is a significant drop in their toughness The current outcomes are useful for applications using CFRP under impact loading at low temperatures
6 citations
TL;DR: In this article, the behavior and after effects which had been resulted from the coated reactive fragments impacting the steel targets, the 14.5mm ballistic rifle had been adopted to complete the experiments that the 6mm Q235A steel targets was impacted by the steel fragments and the reactive fragments, composed by metal/ polymer coated with steel, with the same mass and size.
Abstract: For research the behavior and after effects which had been resulted from the coated reactive fragments impacting the steel targets, the 14.5mm ballistic rifle had been adopted to complete the experiments that the 6mm Q235A steel targets was impacted by the steel fragments and the reactive fragments, composed by metal/ polymer coated with steel, with the same mass and size. Afterwards, the v50 ballistic-limited velocity and the law of the damage effects on the after effect-targets had been discovered. The results indicate that the integral strength of the coated reactive fragments was lower than that of the inert steel fragments, which lead to the reductions of the penetration performance. The v50 ballistic-limited velocity, resulted of the coated reactive fragments impacting the 6mm Q235A steel targets, was 709m/s and it was 1.33 times than that of the steel fragments with the same mass and size. The reaming enhanced effects on the after effect-targets could be produced in the condition that the impact velocity of coated reactive fragments should be greater than 900m/s while the residual velocity should be greater than 181m/s, and that it had been strengthened along with the impact velocity increased. The probable reasons of the damage enhanced effects had been analyzed that the coupled damage effects had been resulted from two parts energy. The results will provide important references to the engineering application of reactive fragments for warheads.
5 citations
TL;DR: In this paper, the numerical simulation of explosive welding of Ti6Al4V-SS304 in the presence of different interlayer materials, i.e., SS304, Ti6al4V, CP-Ti, Cu, Al.
Abstract: Explosive welding is a useful method for joining similar or dissimilar metal alloys that are not easily joined by any other means of welding. Insertion of an interlayer between two-parent plates is beneficial to control the welding parameters and improve the welding quality. In order to investigate the importance of interlayer during the explosive welding process, this paper presents the numerical simulation of explosive welding of Ti6Al4V-SS304 in the presence of different interlayer materials, i.e. SS304, Ti6Al4V, CP-Ti, Cu, Al. To understand the whole welding process with efficient computational time, coupled smoothed particle hydrodynamics -Euler -Arbitrary Lagrangian-Eulerian formulation was opted. Results were analyzed on the basis of different material interlayers. Welding parameters, i.e. pressure, temperature, plastic strain and interface morphology revealed that interlayer improved the welding quality. Furthermore, as an interlayer, the materials with high strength showed high welding strength.
5 citations
TL;DR: Players can reduce the flight height, drop point distance and flight time of ping pong ball by increasing the top spinning speed, so as to improve the opponent’s counterattack difficulty.
Abstract: Table tennis is a popular sport in China. It has a low barrier to entry and also has difficult techniques. In order to improve the skills of table tennis match between players, this paper introduced the dynamic analysis of ping pong ball in flight after being hit. The main content was the stress analysis in the flight of ping pong ball. Moreover, the Magnus force caused by rotation was considered. The dynamic model of ping pong ball flight was built, the flight track of top spinning ball at 0, 30, 60, 90 and 120 r/s was simulated using Java software. The actual flight track of ping pong ball under the same conditions was obtained using the table tennis serving machine and high-speed camera to verify the effectiveness of the dynamic model. The results showed that the track obtained by the dynamic model basically coincided with the actual track, which verified the validity of the dynamic model; the maximum height and drop point distance of ping pong ball decreased with the increase of spinning speed of top spinning ball; the flight time of ping pong ball decreased with the increase of spinning speed of top spinning ball. To sum up, players can reduce the flight height, drop point distance and flight time of ping pong ball by increasing the top spinning speed, so as to improve the opponent’s counterattack difficulty.
4 citations
TL;DR: This review aims to assist aerodynamic noise in three industrial fields: Aerospace, Turbomachinery and Automotive by investigating similarities in noise reduction techniques between these industries, and offers an outlook for noise Reduction techniques in future.
Abstract: This review aims to assist aerodynamic noise in three industrial fields: Aerospace, Turbomachinery and Automotive. In this review the general terms in aeroacoustics is defined; and aerodynamic noise sources are recognized. The paper also reviews the brief literature on noise reduction techniques, with a particular focus on the state of the art numerical and experimental works. In Addition, developments in low speed designs for aerodynamic noise reduction, some passive and active methods for example serrated boundaries, porous media, noise absorber, and etc. are discussed. By investigating similarities in noise reduction techniques between these industries, this paper offers an outlook for noise reduction techniques in future.
3 citations
TL;DR: In this article, the authors compared the conventional air-filled tire with a nonpneumatic tire to improve the grip in the Arctic conditions, and the results proved the nonpuneumatic tires have a more concentrated pressure profile with higher pressure values.
Abstract: The harsh climate of the Arctic has always posed significant challenges to car drivers. The severe loss in traction due to snow and icing on the roads has led to an increased risk of collisions. The chapter compares the conventional air-filled tire with a nonpneumatic tire to improve the grip in the Arctic conditions. The grip obtained for tires is determined by the weight of the car and the friction between the tire and the road. The friction coefficient, used to determine friction, is a function of the contact pressure. This chapter discusses research work to obtain a concentrated pressure profile for the airless tire, compared to a conventional tire. A finite element analysis using ANSYS® Workbench is performed on two distinct models. The different pressure profiles of the models are analyzed, and the results proved the nonpneumatic tires have a more concentrated pressure profile with higher-pressure values.
2 citations
TL;DR: The paper gives a proposal for improving the laser thermography test procedure through data parameterization (curve fitting) for infrared sequences, which allows for reduction of output data size, in particular temporary data storage in RAM.
Abstract: The paper shows the concept of Laser Spot Thermography test rig with real time data processing. Laser Spot Thermography is a promising method for non-destructive testing applications especially, when fully non-contact procedure is required. Unfortunately, the procedure as of now is hard to apply, due to technical difficulties related with data processing. Laser thermography test procedure involves recording of multiple sequences (even hundreds), which have to be processed and evaluated as a whole. The industry requires quick and precise results, which is hard to achieve with the amount of output data from the currently known test procedure. The paper gives a proposal for improving the laser thermography test procedure through data parameterization (curve fitting) for infrared sequences. The data parameterization allows for reduction of output data size, in particular temporary data storage in RAM. The reduction of data size leads to faster real time processing.
2 citations
TL;DR: A finite volume based Eulerian-Lagrangian model has been created within OpenFOAM® in order to predict the behavior of particle clouds as well as particle deposition thicknesses on substrates under the influence of electro-static effects as discussed by the authors.
Abstract: A finite volume based Eulerian-Lagrangian model has been created within OpenFOAM® in order to predict the behavior of particle clouds as well as particle deposition thicknesses on substrates under the influence of electro-static effects. The model resolves close to electrode effects as well as phenomena within the entire deposition chamber. It considers fluid dynamic effects, particle inertia, gravity, electric- as well as mechanic particle-particle interaction, corona formation, dynamic particle charging mechanisms, and coupling of particle motion to Reynolds-Averaged Navier-Stokes (RANS) based flow simulations. Resulting deposition pattern predictions were experimentally validated. It is demonstrated qualitatively and quantitatively that the measured deposition thicknesses and patterns vary by; i) applied voltage, ii) airflow rate, pistol-substrate iii) distance and iv) angle. Furthermore, the software has been prepared such that it works on the cloud computing software KaleidoSim®, which enables the simultaneous browser-based running of hundreds of cases for large parameter studies.
2 citations
TL;DR: In this article, a numerical study of natural convection heat transfer inside the inclined wavy solar collectors containing nanofluid in Bechar region is presented. But the authors assume that the vertical walls are adiabatic.
Abstract: The present paper gives a numerical study of natural convection heat transfer inside the inclined wavy solar collectors containing nanofluid in Bechar region. Bechar is located in the southwest of Algeria and belongs to the semi-arid zone. The solar deposit of this city corresponds to an angle of inclination of a=37°.The collector has a wavy absorber and cover. The inclined corrugated walls are maintained at constant temperature but different values. The vertical walls are assumed to be adiabatic. The nanofluid used is Al2O3-water. This problem consists in solving the system of equations containing: mass conservation, Navier Stokes and energy with adapted simplified hypotheses. Transport equations are solved numerically by finite element method. Governing parameters are taken as Rayleigh number (from 105 to 4´106), volume fraction (from 0 to 10%), amplitude of wavy cover (from 0 to 0.2) and wave of number (from 1.5 to 3.5). Results are presented by stream function and overage Nusselt numbers.
2 citations
TL;DR: In this paper, the results of different types of surface treatments of natural fibrous materials, chiefly Calotropis procera and Sisal fibers, on the mechanical properties of fiber composites are compared.
Abstract: There have been numerous endeavors to replace synthetic fibers with natural fibers in fiber reinforced composites, due to increasing environmental alertness and diminution of oil assets. The information that natural fibers are existing inexpensively and in plenty, being biodegradable and low density, have driven many scientists throughout the world to reconnoiter their application potential in several industrial segments. Nevertheless, natural fibers also require some confines such as high moisture absorption and subsequent swelling and degradation, poor chemical and fire resistance, high dispersion of mechanical properties, poor interfacial interactions with polymeric matrices. Consequently, there is an enormous concern to modify the surface of natural fibers through many techniques, in order to overcome their intrinsic downsides and to effectively utilize these materials in different applications. The chemical treatment of fiber is intended at improving the adhesion between the fiber surface and the matrix. Modification in fiber surface results with increase in fiber strength. This study compares the result of different types of surface treatments of natural fibrous materials, chiefly Calotropis procera and Sisal fibers, on the mechanical properties of fiber composites. The application of surface treatments on fibrous materials can improve the compatibility with composite materials.
TL;DR: This study provides a helpful approach for an effective utilization and combination of reliability and vulnerability indices to improve the functioning and security, and to take an adequate decision on the system state.
Abstract: The exploitation of the structures (planes, engines …) and of the infrastructures (dams, nuclear thermal power stations ...) with a very high cost of realization and a significant working life must be done with a risk of damages and failures reduced and controlled. This paper proposes a case study for the risk management of a hydraulic structure under random contingencies effects by using reliability and vulnerability measures. The reliability which can be defined as the probability that the system will remain in a non-failure state, and vulnerability which represents the system’s susceptibility to failure have been investigated in this paper. Our study provides a helpful approach for an effective utilization and combination of reliability and vulnerability indices to improve the functioning and security, and to take an adequate decision on the system state.
TL;DR: In this article, the authors presented a 3D model in new technique fibers distribution of concrete composite for thermal conductivity prediction, in order to understand thermal interaction of the wall for an insulating system, the model provides four level range of fibers number (100, 150, 200 and 250 fibers number) to analyze fiber network existing.
Abstract: The current work presenting a 3D model in new technique fibers distribution of concrete composite for thermal conductivity prediction. In order to understand thermal interaction of the wall for an insulating system, the model provides four level range of fibers number (100, 150, 200 and 250 fibers number) to analyze fiber network existing. The fibers constructed by points neighbor attach from randomly launching order to perform such spline. MATLAB software was reliable to generate fibers structure algorithm before export to computer-aided design file. The natural fibers of oil palm, coconut and sugar cane were simulated using finite element method to study characteristic and nature behavior for insulating material. Representative volume element and grid independence study was analysis for validation model. The simulation demonstrated that improvement in insulating material around 0.65% by using 250 coconut fibers number which lower compare to plain concrete even to oil palm and coconut fiber.
TL;DR: In this article, the percolation mechanics of steam assisted gravity drainage are introduced, combined with the well group structure of steam-assisted gravity drainage, and the swept volume of steam and the influence rules of the vapor front migration are analyzed.
Abstract: The degree of steam overlay and descriptions of the migration rules for vapor front is considered one of the greatest challenges to research the seepage laws of steam assisted gravity drainage. In order to surmount these challenges, the theory of percolation mechanics are introduced, combined with the well group structure of steam assisted gravity drainage, we do workings such as establishing the mathematical model of the pressure field, applying the steam overlap theory and simplifying the steam overlap coefficient, adopting the technology of database and mapping to display the trends of vapor front intuitively. At last, combined with production factor and reservoir thickness, we analyze the swept volume of steam and the influence rules of the vapor front migration. Understanding the achievements will provide a scientific basis to the improvement of steam’s sweep volume in symmetry elements, displaying the working degree of reservoirs intuitively as well as the efficient development of steam assisted gravity drainage.
TL;DR: Specific focus lies on the construction of streamlines, for which the streamfunction approach and the particle tracing technique are applied, and the accuracy of such mixed dimension approaches is examined.
Abstract: Open and closed faults, that are highly permeable or impermeable relative to the porous matrix in which they are embedded, show a strong influence on the fluid flow regime. The modelling of such thin structures may face severe problems, as high demands on storage requirement and execution time. Meshes require extremely fine resolution within the thin object and in its vicinity. The problems are much less severe, if the thin objects are represented in a lower dimension than the model domain. The resulting combined 2D/1D or 3D/2D models constitute a multi-physics approach. For basic benchmark problems we examine the accuracy of such mixed dimension approaches. We compare with the full dimensional model and with analytical solutions. Specific focus lies on the construction of streamlines, for which the streamfunction approach and the particle tracing technique are applied. Finally advantages and disadvantages of the various numerical approaches are summarized.
TL;DR: Predicting the calm water ship resistance using CFD simulations, using the Flow-3D software package, of a roll-on/roll-off passenger (RoPax) ferry was investigated and multiple meshes were used to check the mesh sensitivity.
Abstract: While designing the power requirements of a ship, the most important factor to be considered is the ship resistance, or the sea drag forces acting on the ship. It is important to have an estimate of the ship resistance while designing the propulsion system since the power required to overcome the sea drag forces contribute to ‘losses’ in the propulsion system. There are three main methods to calculate ship resistance: Statistical methods like the Holtrop-Mennen (HM) method, numerical analysis or CFD (Computational Fluid Dynamics) simulations, and model testing, i.e. scaled model tests in towing tanks. At the start of the design stage, when only basic ship parameters are available, only statistical models like the HM method can be used. Numerical analysis/ CFD simulations and model tests can be performed only when the complete 3D design of the ship is completed. The present paper aims at predicting the calm water ship resistance using CFD simulations, using the Flow-3D software package. A case study of a roll-on/roll-off passenger (RoPax) ferry was investigated. Ship resistance was calculated at various ship speeds. Since the mesh affects the results in any CFD simulation, multiple meshes were used to check the mesh sensitivity. The results from the simulations were compared with the estimate from the HM method. The results from simulations agreed well with the HM method for low ship speeds. The difference in the results was considerably high compared to the HM method for higher ship speeds. The capability of Flow-3D to perform ship resistance analysis was demonstrated.
TL;DR: In this paper, the influence of gear surface roughness on oil film thickness and fatigue life analysis based on the thickness of the oil film on the gear tooth surface has been investigated.
Abstract: Increasingly demanding performance standards and operating requirements are driving the growing interest on the influence of gear oil film on reliability under the condition of high speed and heavy load. The fatigue life of gears can be increased by optimizing the oil film thickness on the gear tooth surface. The oil film thickness can reflect the ability of the gear to resist pitting and gluing failure. Many theories and experiments are devoted to the study of the oil film thickness. The improvement of gear manufacturing accuracy also makes the influence of tooth surface roughness on oil film thickness not negligible. In order to compile and categorize key investigations in an expansive field with substantial recent research, this work reviews oil film thickness with focus on numerical calculation methods, influence of gear surface roughness on oil film thickness and fatigue life analysis based on oil film thickness.
TL;DR: In this paper, it is shown that in layered systems different convective flow patterns appear than in the single-layer case, where the number and constellation of convection cells characterize steady flow patterns.
Abstract: Convective motions are a multi-physics phenomenon, in which flow and transport processes interact in a two-way coupling. The density of the fluid depends on the value of transport variable and this back-coupling leads to non-linear behaviour. For the classical constellation of a closed fluid container heated from below convective motions appear, when a critical threshold for the Rayleigh number is exceeded. The heat transfer due to convection is much higher than in the case of pure conduction. Here systems of three layers are examined in detail. Using numerical CFD modelling it is shown that in layered systems different convective flow patterns appear than in the single layer case. The number and constellation of convection cells characterize steady flow patterns. Using a parametric sweep over the relevant parameter range of layer Rayleigh numbers and layer thicknesses we determine diagrams that show the excess heat or mass transfer of the dominant convection patterns, measured by the Nusselt- or Sherwood numbers.
TL;DR: In this article, the Proper Orthogonal Decomposition (POD)-Galerkin projection method is applied to solve the problem of non-isothermal mixing in a T-junction pipe with the inlet velocities treated as parameters.
Abstract: Computational fluid dynamics modeling has been widely applied to study flow and heat transfer problems in nuclear engineering. However, due to the prohibitively high computation cost, fast or real-time solution of nontrivial problems is still a challenging task under context of many-quires. Model order reduction is an efficient way to achieve significant speedup. For the turbulent mixed heat transfer problems, the Proper Orthogonal Decomposition (POD)-Galerkin projection method is introduced and then applied to solve the problem of non-isothermal mixing in a T-junction pipe with the inlet velocities treated as parameters. It is shown that a speedup of two orders of magnitude has been achieved. For new parameters out of the scope of the samples, the reduced order model still can give satisfactory results.
TL;DR: In this paper, a hybrid RBF with no shape parameter is proposed and tested with some scattered data interpolation problems and the results have appeared promising whereas the appearance of the shape parameter remains a difficulty when deploying.
Abstract: A Hybrid RBF has recently been proposed and tested with some scattered data interpolation problems and the results have appeared promising whereas the appearance of the shape parameter remains a difficulty when deploying. This work, therefore, focuses on three objectives; firstly, it is aimed to extend the use of the newly proposed-RBF to application of RBF-collocation method. Secondly, realizing the burden attributed to the lack of information on choosing an optimum shape parameter, the hybrid RBF is then modified where the shape parameter is no longer included. Thirdly, it is to investigate its application/implementation towards solving PDEs particularly those in both linear and non-linear form. It has been found in this work that the new RBF of this HyBrid form with no parameter can well be a good candidate and truly deserves further study with more complex problems.
TL;DR: The development of cost-effective and simple impeller wheel for a fluid pump in the truck cooling system and works very effectively in spite of performance degradation by 5% in comparison to the closed-type impellers.
Abstract: Typically, closed-type impellers are more efficient than open-type impellers, but in the manufacture of closed-type impeller, cost of wheels is higher. This paper describes the development of cost-effective and simple impeller wheel for a fluid pump in the truck cooling system. To perform this task, the numerical computations of a standard impeller wheel were carried out, its characteristics were also obtained from a test bench, the standard impeller wheel model was verified. The open-type impeller wheel was developed according to the current dimensions of standard impeller wheel and then analyzed with the numerical computations by the software ANSYS CFX (Academic license) computational fluid dynamics. The developed open-type impeller wheel works very effectively in spite of performance degradation by 5% in comparison to the closed-type impeller wheel. When working as a part of engine, the pump efficiency is 0.552-0.579. The maximum value of the pump efficiency is 0.579, it can be achieved at the highest speed of the pump (4,548 rpm and 655 l/min)
TL;DR: In this article, a multi-physics coupling simulation study on the pre-cooling problem of the LNG discharge pipe with a π-shaped elbow is carried out, and the analysis from BOG and LNG pre cooling processes respectively shows that the fluid with low temperature and high density is mainly concentrated at the bottom of the pipe and outside the bend, the wall temperature has a sudden drop at the bend and there is a large temperature difference between the gas side and the liquid side wall surface.
Abstract: The low-temperature fluid flowing into the LNG unloading pipeline will cause violent heat exchange phenomenon, resulting in damage to the pipeline and affecting normal operation. Therefore, pre-cooling treatment is required in advance. Considering the fluid-solid heat transfer and fluid flow characteristics comprehensively, multi-physics coupling simulation study on the pre-cooling problem of the LNG discharge pipe with a π-shaped elbow is carried out. The analysis from BOG and LNG pre-cooling processes respectively shows that: the fluid with low temperature and high density is mainly concentrated at the bottom of the pipe and outside the bend, the wall temperature has a sudden drop at the bend, and there is a large temperature difference between the gas side and the liquid side wall surface. Mixed convection heat exchange mainly occurs in the tube. There will be a small area of natural convection-dominated heat exchange state in the elbow and the downstream pipe section.
TL;DR: In this paper, a multiphysics coupling calculation considering the influence of fluid flow characteristics in ocean tidal flow environment and mechanical properties of pipeline solid structure on vibration characteristics of S-type pipeline was performed.
Abstract: Pipeline-induced vibration phenomena caused by waves and currents during the transportation of oil and natural gas pipelines.Multiphysics coupling calculation considering the influence of fluid flow characteristics in ocean tidal flow environment and mechanical properties of pipeline solid structure on vibration characteristics of S-type pipeline. The analysis of the velocity of the fluid domain and the distribution of the stress distribution of the pipeline, combined with the time history and amplitude of the monitoring point and axis of the pipeline, analyzes the flow-induced vibration response characteristics of the S-transport pipeline. The results show that under the cyclic flow of the two-way tidal basin, the velocity field on the deformation side of the pipeline is lower, the stress at the solid support end is higher than that in the riser region, and the time-displacement of the pipeline fluctuates periodically, and the displacement of the pipeline axis increases sharply in the riser pipe section. It exhibits a normal distribution with extreme values at the center of the pipe segment. The maximum single-pass amplitude in the Verticality basin is twice that of the Parallel basin and the maximum amplitude is about 1D.
TL;DR: In this article, the authors introduced the sulfur removal principle and the mathematical model of flue gas flow of the wet spray method, and the flow field of the desulfurization tower before and after optimization was simulated by ABAQUS software and the model test was carried out under the similar condition by using the model whose scale was reduced 10 times.
Abstract: The combustion of fossil fuels will not only produce a lot of carbon dioxide, but also convert sulfur dioxide into sulfur dioxide, which will seriously pollute the atmosphere. Rapid and efficient desulfurization is very important for enterprises that consume a lot of fossil fuels. This paper briefly introduced the sulfur removal principle of and the mathematical model of flue gas flow of the wet spray method. After that, the flow field of the desulfurization tower before and after optimization was simulated by ABAQUS software, and the model test was carried out under the similar condition by using the model whose scale was reduced 10 times. The results showed that the velocity distribution of the spray layer and smoke outlet in the section velocity distribution map obtained by numerical simulation was not even and the velocity distribution after optimization was obviously uniform, while the velocity distribution of the demisting layer before and after optimization was relatively uniform and had little change. The results obtained by the test of the model with the reduced scale were close to the numerical simulation results, and the removal rate of sulfur dioxide was greatly improved after optimization.
TL;DR: In this article, a multi-physics coupling study is carried out by considering the fluctuation of the interphase dynamic interface and its flow characteristics as well as the mechanical properties of the solid structure of the pipeline.
Abstract: The multi-physics coupling study is carried out by considering the fluctuation of the interphase dynamic interface and its flow characteristics as well as the mechanical properties of the solid structure of the pipeline. By capturing the dynamic interface between gas and liquid, calculating its flow characteristics, combined with the time-history displacement and amplitude of the characteristic monitoring point and the axis of the pipeline, the FIV response characteristics of the basin in the S-type conveying pipe are analyzed. The results show that the dominant area of single gas phase or single liquid phase is not easy to deform and vibrate. The transition and persistence of the flow pattern in the mixed turbulent flow area and the weak regular fluctuation of the flow field in the pipe stimulate the pipe wall to cause stress reaction, leading to the time-history vibration with great difference in the pipe.
TL;DR: In this paper, two typical arrangements of bowing-out dislocation segments that yield mutually-distinct trends are examined by utilizing the Field Theory of Multiscale Plasticity (FTMP) based duality diagram representation scheme.
Abstract: This study attempts to quantitatively evaluate the apparent reduction in elastic moduli, generally observed in metallic materials during unloading and/or cyclic elasto-plastic deformation, based on Field Theory of Multiscale Plasticity (FTMP). Two typical arrangements of bowing-out dislocation segments that yield mutually-distinct trends are examined by utilizing the FTMP-based duality diagram representation scheme. It is demonstrated that not only the scheme allows us to visualize the associated energy flow but also to correlate the resultant apparent shear modulus reduction rate in a unified manner by the duality coefficient measured on the duality diagrams. The scheme is demonstrated to be effective also for more complex cases accompanied by pinning/unpinning and the following relaxation processes.
TL;DR: In this paper, the crystal lattice integrity of the diamonds synthesized by the dynamic loading methods is poor, and the diamonds possess the characteristic of polycrystalline coalescence.
Abstract: The crystal characteristics of the diamond samples that are synthesized by several dynamic loading methods, i.e., explosion and impact, have been characterized by XRD and TEM and compared with the diamonds synthesized by static high-temperature and high-pressure method. The crystal lattice integrity of the diamonds synthesized by the dynamic loading methods is poor, and the diamonds possess the characteristic of polycrystalline coalescence. Similar to the static diamonds, the diamonds synthesized by the methods of plane shock wave and detonation products are also single cubic crystal, while the diamonds synthesized by the methods of axial symmetry shock wave and direct detonation have different proportions of cubic and hexagonal crystal structures. The reasons for the formation of these properties have been studied by analyzing the synthesis process and technical characteristics. The results are helpful for the reasonable application of these diamond products, and also have some significance in deepening the understanding of the synthesis mechanism of different dynamic loading methods.