On the Vacuum Hydrodynamics of Moving Bodies—The Theory of General Singularity

The Theory of General Singularity is presented, unifying quantum field theory, general relativity, and the standard model. This theory posits phonons as fundamental excitations in a quantum vacuum, modeled as a Bose-Einstein condensate. Through key equations, the role of phonons as intermediaries between matter, energy, and spacetime geometry is demonstrated. The theory expands Einsteins field equations to differentiate between visible and dark matter, and revises the standard model by incorporating phonons. It addresses dark matter, dark energy, gravity, and phase transitions, while making testable predictions. The theory proposes that singularities, the essence of particles and black holes, are quantum entities ubiquitous in nature, constituting the very essence of elementary particles, seen as micro black holes or quantum fractal structures of spacetime. As the theory is refined with increasing mathematical rigor, it builds upon the foundation of initial physical intuition, connecting the spacetime continuum of general relativity with the hydrodynamics of the quantum vacuum. Inspired by the insights of Tesla and Majorana, who believed that physical intuition justifies the infringement of mathematical rigor in the early stages of theory development, this work aims to advance the understanding of the fundamental laws of the universe and the perception of reality.

Quasi-static simulation of droplet morphologies using a smoothed particle hydrodynamics multiphase model

Numerical simulation of the morphology of a droplet deposited on a solid surface requires an efficient description of the three-phase contact line. In this study, a simple method of implementing the contact angle is proposed, combined with a robust smoothed particle hydrodynamics multiphase algorithm (Zhang 2015). The first step of the method is the creation of the virtual liquid-gas interface across the solid surface by means of dummy particles, thus the calculated surface tension near the triple point serves to automatically modulate the dynarnic contact line towards the equilibrium state. We simulate the evolution process of initially square liquid lumps on fiat and curved surfaces. The predictions of droplet profiles are in good agreement with the analytical solutions provided that the macroscopic contact angle is accurately implemented. Compared to the normal correction method, the present method is straightforward without the need to manually alter the normal vectors. This study presents a robust algorithm capable of capturing the physics of the static welling. It may hold great potentials in bio-inspired superhydrophobic surfaces, oil displacement, microfluidics, ore floatation, etc.

New Analytical Study of the Effects Thermo-Diffusion, Diffusion-Thermo and Chemical Reaction of Viscous Fluid on Magneto Hydrodynamics Flow in Divergent and Convergent Channels

In this paper, the magneto hydrodynamic (MHD) flow of viscous fluid in a channel with non-parallel plates is studied. The governing partial differential equation was transformed into a system of dimensionless non-similar coupled ordinary differential equation. The transformed conservations equations were solved by using new algorithm. Basically, this new algorithm depends mainly on the Taylor expansion application with the coefficients of power series resulting from integrating the order differential equation. Results obtained from new algorithm are compared with the results of numerical Range-Kutta fourth-order algorithm with help of the shooting algorithm. The comparison revealed that the resulting solutions were excellent agreement. Thermo-diffusion and diffusion-thermo effects were investigated to analyze the behavior of temperature and concentration profile. Also the influences of the first order chemical reaction and the rate of mass and heat transfer were studied. The computed analytical solution result for the velocity, temperature and concentration distribution with the effect of various important dimensionless parameters was analyzed and discussed graphically.

Numerical Investigation of Penetration in Ceramic/Aluminum Targets Using Smoothed Particle Hydrodynamics Method and Presenting a Modified Analytical Model

Radius of ceramic cone can largely contribute into final solution of analytic models of penetration into ceramic/metal targets.In the present research,a modified model based on radius of ceramic cone was presented for ceramic/aluminum targets.In order to investigate and evaluate accuracy of the presented analytic model,obtained results were compared against the results of the Florence’s analytic model and also against numerical modeling results.The phenomenon of impact onto ceramic/aluminum composites were modeled using smoothed particle hydrodynamics(SPH)implemented utilizing ABAQUS Software.Results indicated that,with increasing initial velocity and ceramic thickness and decreasing support layer thickness,the radius of ceramic cone decreases;this ends up increasing residual velocity of the projectile and penetration time and extending the area across which the pressure is distributed.These findings indicate enhanced levels of target energy absorption and the required energy for bending and tensioning the target.As such,it can be observed that,at the same thickness and areal density,the ceramic target has its efficiency enhanced with increasing ceramic thickness and decreasing the support layer thickness.Finally,the results revealed that the associated data with SPH confirm the modified analytic model at higher accuracy than the Florence’s analytic model.

Monolithic Coupling of the Pressure and Rigid Body Motion Equations in Computational Marine Hydrodynamics

In Fluid Structure Interaction(FSI) problems encountered in marine hydrodynamics, the pressure field and the velocity of the rigid body are tightly coupled. This coupling is traditionally resolved in a partitioned manner by solving the rigid body motion equations once per nonlinear correction loop, updating the position of the body and solving the fluid flow equations in the new configuration. The partitioned approach requires a large number of nonlinear iteration loops per time–step. In order to enhance the coupling, a monolithic approach is proposed in Finite Volume(FV) framework,where the pressure equation and the rigid body motion equations are solved in a single linear system. The coupling is resolved by solving the rigid body motion equations once per linear solver iteration of the pressure equation, where updated pressure field is used to calculate new forces acting on the body, and by introducing the updated rigid body boundary velocity in to the pressure equation. In this paper the monolithic coupling is validated on a simple 2D heave decay case. Additionally, the method is compared to the traditional partitioned approach(i.e. "strongly coupled" approach) in terms of computational efficiency and accuracy. The comparison is performed on a seakeeping case in regular head waves, and it shows that the monolithic approach achieves similar accuracy with fewer nonlinear correctors per time–step. Hence, significant savings in computational time can be achieved while retaining the same level of accuracy.

The assessment of time dependent flow of Williamson fluid with radiative blood flow against a wedge

The present pagination reports both Brownian diffusion and thermophoresis aspects subject to magneto hydrodynamic Williamson fluid model.Assuming the flow is unsteady and blood is treated as Williamson fluid over a wedge with radiation.The governing equations are transformed into ordinary differential equations by using similarity variables.The analytical solutions of the transformed governing equations are obtained by using the RK 4th order method along with shooting technique solver.The effects of various physical parameters such as Hartmann number,local Weissenberg number,radiation parameter,unsteadiness parameter,Prandtl number,Lewis number,Brownian diffusion,thermophoresis,wedge angle parameter,moving wedge parameter,on velocity,temperature,concentration,skin friction,heat transfer rate and mass transfer rate have been discussed in detail.The velocity and temperature profile deprives for larger We and an opposite trend is observed for concentration.The radiation parameter is propositional to temperature and a counter behaviour is observed for Pr.

Numerical Simulation of Bubble Formation at a Single Orifice in Gas-fluidized Beds with Smoothed Particle Hydrodynamics and Finite Volume Coupled Method

A coupled method describing gas–solid two-phase flow has been proposed to numerically study the bubble formation at a single orifice in gas-fluidized beds.Solid particles are traced with smoothed particle hydrodynamics,whereas gas phase is discretized by finite volume method.Drag force,gas pressure gradient,and volume fraction are used to couple the two methods.The effect of injection velocities,particle sizes,and particle densities on bubble growth is analyzed using the coupled method.The simulation results,obtained for two-dimensional geometries,include the shape and diameter size of a bubble as a function of time;such results are compared with experimental data,previous numerical results,and other approximate model predictions reported in the literature.Moreover,the flow profiles of gas and particle phases and the temperature distribution by the heat transfer model around the forming bubble are also discussed.All results show that the coupled method efficiently describes of the bubble formation in fluidized beds.The proposed method is applicable for solving gas–solid two-phase flow in fluidization.

Application of CFD Modeling to Hydrodynamics of CycloBio Fluidized Sand Bed in Recirculating Aquaculture Systems

To improve the efficiency of a CycloBio fluidized sand bed(CB FSB) in removal of dissolved wastes in recirculating aquaculture systems, the hydrodynamics of solid-liquid flow was investigated using computational fluid dynamics(CFD) modeling tools. The dynamic characteristics of silica sand within the CB FSB were determined using three-dimensional, unsteady-state simulations with the granular Eulerian multiphase approach and the RNG k-ε turbulence model, and the simulation results were validated using available lab-scale measurements. The bed expansion of CB FSB increased with the increase in water inflow rate in numerical simulations. Upon validation, the simulation involving 0.55 mm particles, the Gidaspow correlation for drag coefficient model and the Syamlal-O'Brien correlation for kinetic granular viscosity showed the closest match to the experimental results. The volume fraction of numerical simulations peaked as the wall was approached. The hydrodynamics of a pilot-scale CB FSB was simulated in order to predict the range of water flow to avoid the silica sand overflowing. The numerical simulations were in agreement with the experimental results qualitatively and quantitatively, and thus can be used to study the hydrodynamics of solid-liquid multiphase flow in CB FSB, which is of importance to the design, optimization, and amplification of CB FSBs.

Parametric study on smoothed particle hydrodynamics for accurate determination of drag coefficient for a circular cylinder

Simulations of two-dimensional(2D) flow past a circular cylinder with the smoothed particle hydrodynamics(SPH) method were conducted in order to accurately determine the drag coefficient. The fluid was modeled as a viscous liquid with weak compressibility. Boundary conditions,such as a no-slip solid wall, inflow and outflow, and periodic boundaries, were employed to resemble the physical problem. A sensitivity analysis, which has been rarely addressed in previous studies, was conducted on several SPH parameters. Hence, the effects of distinct parameters, such as the kernel choices and the domain dimensions, were investigated with the goal of obtaining highly accurate results. A range of Reynolds numbers(1-500) was simulated, and the results were compared with existing experimental data. It was observed that the domain dimensions and the resolution of SPH particles, in comparison to the obstacle size, affected the obtained drag coefficient significantly. Other parameters, such as the background pressure, influenced the transient condition, but did not influence the steady state at which the drag coefficient was determined.

Modified smoothed particle hydrodynamics approach for modelling dynamic contact angle hysteresis

Dynamic wetting plays an important role in the physics of multiphase flow, and has a significant influence on many industrial and geotechnical applications. In this work, a modified smoothed particle hydrodynamics (SPH) model is employed to simulate surface tension, contact angle and dynamic wetting effects at meso-scale. The wetting and dewetting phenomena are simulated in a capillary tube, where the liquid particles are raised or withdrawn by a shifting substrate. The SPH model is modified by introducing a newly developed viscous force formulation at the liquid-solid interface to reproduce the rate-dependent behaviour of the moving contact line. Dynamic contact angle simulations with the interfacial viscous force are conducted to verify the effectiveness and accuracy of this new formulation. In addition, the influence of interfacial viscous forces with different magnitude on the contact angle dynamics is examined by empirical power-law correlations;the derived constants suggest that the dynamic contact angle changes monotonically with the interfacial viscous force. The simulation results are consistent with experimental observations and theoretical predictions, implying that the interfacial viscous force can be associated with the slip length of flow and the microscopic surface roughness. This work demonstrates that the modified SPH model can successfully account for the rate-dependent effects of a moving contact line, and can be used for realistic multiphase flow simulations under dynamic conditions.

Application of Generalized Non-Local Quantum Hydrodynamics to the Calculation of the Charge Inner Structures for Proton and Electron

The proton and electron charge inner structures are considered in the frame of the non-local quantum hydrodynamics based on the non-local physical description. From calculations follow that proton and electron can be considered like charged balls (shortly CB model) which charges are concentrated mainly in the shell of these balls. The proton-electron collision in the frame of CB-model should be considered as collision of two resonators. In this case can be explained a number of character collisional features depending on the initial and final electron energies and the scattering angles.

Improved Model for Soil as a Two-Phase Mixture Based on Smoothed Particle Hydrodynamics (SPH)

It is desired to resolve soil contamination with reduced costs. “Insoluble treatment” is a soil improvement method for heavy metal containing soil, which uses soil mixers to mix soil and soil improvement liquid agents. To reduce the costs of this method, soil mixers have to be optimized. However, it is not achieved due to the lack of theoretical knowledge on mixing solid with liquid. Therefore, a numerical model to simulate the dynamic behavior of solid and liquid is on the development in this study using Smoothed Particle Hydrodynamics (SPH) method. To validate the numerical model, several experiments were carried out and numerically reproduced. The comparisons of the results showed that the numerical model replicated a liquid flow with an error rate of 2.1% and a seepage flow with an error rate up to 26.1%. Especially, the water distribution in the soil pores was highly improved with absolute gaps in volumetric water content up to 4.4% in the porosity range of 10% - 90%. For the water absorption into dry sand, the simulation result became more realistic by concerning soil suction.

Effect of stratification on current hydrodynamics over Louisiana shelf during Hurricane Katrina

Numerical experiments were conducted using the finite volume community ocean model(FVCOM) to study the impact of the initial density stratification on simulated currents over the Louisiana shelf during Hurricane Katrina. Model results for two simulation scenarios, including an initially stratified shelf and an initially non-stratified shelf, were examined. Comparison of two simulations for two-dimensional(2D) currents,the time series of current speed, and variations of cross-shore currents across different sections showed that the smallest differences between simulated currents for these two scenarios occurred over highly mixed regions within 1 radius of maximum wind(RMW) under the hurricane.For areas farther from the mixed zone, differences increased, reaching the maximum values off Terrebonne Bay. These large discrepancies correspond to significant differences between calculated vertical eddy viscosities for the two scenarios. The differences were addressed based on the contradictory behavior of turbulence in a stratified fluid, as compared to a non-stratified fluid. Incorporation of this behavior in the MellorYamada turbulent closure model established a Richardson number-based stability function that was used for estimation of the vertical eddy viscosity from the turbulent energy and macroscale. The results of this study demonstrate the necessity for inclusion of shelf stratification when circulation modeling is conducted using three-dimensional(3D) baroclinic models. To achieve high-accuracy currents, the parameters associated with the turbulence closures should be calibrated with field measurements of currents at different depths.

Geo-Hydrodynamics of Bagjata Area and its Significance with Respect to Seasonal Fluctuation of Groundwater

Bagjata area is a part of Singhbhum Shear Zone (SSZ) falling within Survey of India Toposheets No. 73J/6, J/7, J/10 and J/11. The Subarnarekha River, Sankh Nala and Gohala faults are major disconti-nuities in the area. An attempt has been made to simulate the regional groundwater hydrodynamics. Few dug-wells were monitored for more than a year to find out the seasonal fluctuation changes in the drainage pattern and groundwater level. Groundwater samples were analyzed for physical and chemical analysis. Results show that one of the major discontinuities in the area-the Gohala Fault controls largely the geohydrodynamics of the area. Discharge of groundwater is of effluence type during all the three seasons. The water is safe for drinking as most of the contaminations are much below the permissible limits. No such previous work has been attempted in this area to investigate the groundwater dynamics and hence the selection of few parameters were assumed and taken from similar surrounding aquifer systems for modeling. The groundwater flow was also assumed to be in steady state. The present paper deals with some important aspects related to the hydrological significance of the Bagjata Uranium mining area and its relationship with the local climate, physiography and meteorology. An attempt is also made to simulate the status of groundwater conditions of hard rock aquifers in the region. Further it envisages the necessity of such study being undertaken in the entire SSZ belt to secure precise information about the surface manifestations which govern the groundwater recharge potentiality as well as its quality.

Experimental and numerical investigations of scale-up effects on the hydrodynamics of slurry bubble columns

Experiments and simulations were conducted for bubble columns with diameter of 0.2 m(180 mm i.d.), 0.5 m(476 mm i.d.) and 0.8 m(760 mm i.d.) at high superficial gas velocities(0.12–0.62 m·s-1) and high solid concentrations(0–30 vol%). Radial profiles of time-averaged gas holdup, axial liquid velocity, and turbulent kinetic energy were measured by using in-house developed conductivity probes and Pavlov tubes. Effects of column diameter, superficial gas velocity, and solid concentration were investigated in a wide range of operating conditions. Experimental results indicated that the average gas holdup remarkably increases with superficial gas velocity, and the radial profiles of investigated flow properties become steeper at high superficial gas velocities. The axial liquid velocities significantly increase with the growth of the column size, whereas the gas holdup was slightly affected. The presence of solid in bubble columns would inhibit the breakage of bubbles, which results in an increase in bubble rise velocity and a decrease in gas holdup, but time-averaged axial liquid velocities remain almost the same as that of the hollow column. Furthermore, a 2-D axisymmetric k–ε model was used to simulate heterogeneous bubbly flow using commercial code FLUENT 6.2. The lateral lift force and the turbulent diffusion force were introduced for the determination of gas holdup profiles and the effects of solid concentration were considered as the variation of average bubble diameter in the model. Results predicted by the CFD simulation showed good agreement with experimental data.

Simulation of nanofluid natural convection based on single-particle hydrodynamics in energy-conserving dissipative particle dynamics(eDPD)

In the present study,the nanofliud natural convection is investigated by the energy-conserving dissipative particle dynamics(eDPD)method,where the nanoparticles are considered at the single-particle level.The thermal expansion coefficientβand the viscosityμof the simulated system containing nanoparticles are calculated and found to be in close alignment with the previous simulation results.The single-particle hydrodynamics in e DPD enables simulations of nanofluid natural convection with higher Rayleigh numbers and greater nanoparticle volume fractions.Additionally,this approach is utilized to simulate the nanoparticle distribution during the enhanced heat transfer process in the nanofluid natural convection.The localized aggregation of nanoparticles enhances the heat transfer performance of the nanofluid under specific Rayleigh numbers and nanoparticles volume fractions.

A modified smoothed particle hydrodynamics method considering residual stress for simulating failure and its application in layered rock mass

Residual strength is an indispensable factor in evaluating rock fracture,yet the current Smoothed Particle Hydrodynamics(SPH)framework rarely considers its influence when simulating fracture.An improved cracking strategy considering residual stress in the base bond SPH method was proposed to simulate failures in layered rocks and slopes and verified by experimental results and other simulation methods(i.e.,the discrete element method).Modified Mohr–Coulomb failure criterion was applied to distinguish the mixed failure of tensile and shear.Bond fracture markψwas introduced to improve the kernel function after tensile damage,and the calculation of residual stress after the damage was derived after shear damage.Numerical simulations were carried out to evaluate its performance under different stress and scale conditions and to verify its effectiveness in realistically reproducing crack initiation and propagation and coalescence,even fracture and separation.The results indicate that the improved cracking strategy precisely captures the fracture and failure pattern in layered rocks and rock slopes.The residual stress of brittle tock is correctly captured by the improved SPH method.The improved SPH method that considers residual strength shows an approximately 13%improvement in accuracy for the safety factor of anti-dip layered slopes compared to the method that does not consider residual strength,as validated against analytical solutions.We infer that the improved SPH method is effective and shows promise for applications to continuous and discontinuous rock masses.

A flexible multiscale algorithm based on an improved smoothed particle hydrodynamics method for complex viscoelastic flows

Viscoelastic flows play an important role in numerous engineering fields,and the multiscale algorithms for simulating viscoelastic flows have received significant attention in order to deepen our understanding of the nonlinear dynamic behaviors of viscoelastic fluids.However,traditional grid-based multiscale methods are confined to simple viscoelastic flows with short relaxation time,and there is a lack of uniform multiscale scheme available for coupling different solvers in the simulations of viscoelastic fluids.In this paper,a universal multiscale method coupling an improved smoothed particle hydrodynamics(SPH)and multiscale universal interface(MUI)library is presented for viscoelastic flows.The proposed multiscale method builds on an improved SPH method and leverages the MUI library to facilitate the exchange of information among different solvers in the overlapping domain.We test the capability and flexibility of the presented multiscale method to deal with complex viscoelastic flows by solving different multiscale problems of viscoelastic flows.In the first example,the simulation of a viscoelastic Poiseuille flow is carried out by two coupled improved SPH methods with different spatial resolutions.The effects of exchanging different physical quantities on the numerical results in both the upper and lower domains are also investigated as well as the absolute errors in the overlapping domain.In the second example,the complex Wannier flow with different Weissenberg numbers is further simulated by two improved SPH methods and coupling the improved SPH method and the dissipative particle dynamics(DPD)method.The numerical results show that the physical quantities for viscoelastic flows obtained by the presented multiscale method are in consistence with those obtained by a single solver in the overlapping domain.Moreover,transferring different physical quantities has an important effect on the numerical results.

Smoothed-Particle Hydrodynamics Simulation of Ship Motion and Tank Sloshing under the Effect of Regular Waves

Predicting the response of liquefied natural gas(LNG)contained in vessels subjected to external waves is extremely important to ensure the safety of the transportation process.In this study,the coupled behavior due to ship motion and liquid tank sloshing has been simulated by the Smoothed-Particle Hydrodynamics(SPH)method.Firstly,the sloshing flow in a rectangular tank was simulated and the related loads were analyzed to verify and validate the accuracy of the present SPH solver.Then,a three-dimensional simplified LNG carrier model,including two prismatic liquid tanks and a wave tank,was introduced.Different conditions were examined corresponding to different wave lengths,wave heights,wave heading angles,and tank loading rates.Finally,the effects of liquid tank loading rate on LNG ship motions and sloshing loading were analyzed,thereby showing that the SPH method can effectively provide useful indications for the design of liquid cargo ships.

Analysis of the Driving Force of Hydrodynamics in Lake Naivasha, Kenya

The hydrodynamics in Lake Naivasha, a shallow endorheic lake, are simulated using the Delft3D Flow Module to investigate the major driving forces of hydrodynamics in the lake. The results showed wind as the major forcing. The shallow zones of the lake showed currents movement in the same direction as the wind while the deep zones showed currents movements against the wind direction. These findings were confirmed and further explained using an idealized model. Limited exchange between the Crescent Lake (crater lake which is temporally separated from the lake during low water levels) and the main lake was observed. These findings can explain the spatial variability of the water quality in the lake. Similar studies could be used in exploratory studies of the spatial-temporal variability in water quality in other shallow water systems.