The water wave generation by wave paddle and a freely falling rigid body are examined by using an Incompressible SMOOTHED PARTICLE HYDRODYNAMICS (ISPH). In the current ISPH method, the pressure was evaluated by solving pressure Poisson equation using a semi-implicit algorithm based on the projection scheme and the source term of pressure Poisson equation contains both of divergence free velocity field and density invariance condition. Here, the fluid-structure interaction is introduced in free surface flows and the structure is taken as a rigid body motion. In this study, we generated the water waves using the Scott Russell wave generator, in which the heavy box sinking vertically into water. Also, the solitary wave is generated by using the wave paddle and the generated solitary wave pro les are compared with the available results with a good agreement. Free falling of torpedo over the water in tank was simulated by using 3D-ISPH method.

This research aims to construct a three-dimensional numerical model for modeling friction stir extrusion using the completely Lagrangian method, SMOOTHED PARTICLE HYDRODYNAMICS (SPH). For extrusion simulations, the Finite Element Method (FEM) is extensively utilized; however, it has limitations due to excessive element deformation. Because the PARTICLE-based method eliminates the usage of volumetric elements, SPH can be a viable alternative. The performance of the SPH model was evaluated using different PARTICLE sizes. The results showed that the smaller PARTICLE size improves the temperature results as well as the shape of the wire produced. Then the mechanical and microstructural properties of the produced wires were investigated. The results show that the grain size in the center of the wire is larger than its perimeter due to the lower strain rate in this area. Increased strain reduces grain size in the produced microstructure by increasing nucleation sites during recrystallization, as is well known. The wire microhardness in the centre is 121 HV, whereas it is 129 HV in the periphery. Grain size is the main reason of increased hardness near the sample's periphery.

To date, the SMOOTHED PARTICLE HYDRODYNAMICS (SPH) method has been successfully applied to reproduce the HYDRODYNAMICS behind three-dimensional flow-structure interactions. However, as soon as the effect of flow resistance becomes significant, the results obtained are not consistent with observations. This is the case for open channel flows (OCF), in which the water surface is largely influenced by the boundary friction. The roughness generated by the current boundary condition methodologies is solely numerical and cannot be associated to physical values of friction. In light of this challenge, the authors present a novel formulation for the friction boundary condition. The new implementation includes an additional shear stress at the boundaries to reproduce roughness effects, allowing for the adequate three-dimensional simulation of open channel flows using the SPH method. Finally, in order to reduce the high computational cost, typical of the Lagrangian models, without interfering in the representativeness of the SPH simulations, a criterion to define the adequate fluid PARTICLE size is proposed.

In this paper, breakup of liquid jet is simulated using SMOOTHED PARTICLE HYDRODYNAMICS (SPH) which is a meshless Lagrangian numerical method. For this aim, flow governing equations are discretized based on SPH method. In this paper, SPHysics open source code has been utilized for numerical solutions. Therefore, the mentioned code has been developed by adding the surface tension effects. The proposed method is then validated using dam break with obstacle problem. Finally, simulation of two dimensional liquid jet flow is carried out and its breakup behavior considering one-phase flow is investigated. Length of liquid breakup in Rayleigh regime is calculated for various flow conditions such as different Reynolds and Weber numbers and the results are validated by an experimental correlation. The whole numerical solutions are accomplished for both Wendland and cubic spline kernel functions and Wendland kernel function gave more accurate results. The results are compared to MPS method for inviscid liquid as well. The accomplished modeling showed that SMOOTHED PARTICLE HYDRODYNAMICS (SPH) is an efficient method for simulation of liquid jet breakup phenomena.

In this research, using a mesh free PARTICLE method based on Lagrangian formulation called SMOOTHED PARTICLE HYDRODYNAMICS (SPH), sand behaviour on the transformation of sandy beaches was simulated. In this paper, weakly compressibility condition was used for SPH algorithm. This algorithm is based on the application of Tait equation of state rather than Poisson’ s equation for pressure calculation. In this research, sand behaviour was evaluated as a non-Newtonian fluid. In the validation process, flow under a gate, a dam break and sedimentation problem as a water-sediment two-phase flow were investigated. The results were validated with experimental data and numerical values and a good agreement was observed. The appearance of sandy beaches with given physical and rheological characteristics under the effect of a sinusoidal wave generator pedal was modeled under yield stress values of τ y = 200 Pa and τ y = 1000 Pa at different times. The shape of the simulated bed changed rapidly under the yield stress of τ y = 200 Pa, so that the form of the bed ripples reached a relative stability after 2-4 seconds.

One of the most advanced methods of cutting materials is water jet cutting. Due to its advantages over other cutting methods, it has been widely used in recent years. Cutting with a water jet is a subset of fluid and structure interaction issues in which water flows into the boundaries of the rock, and this changes the shape of the rock in the impact area. In order to examine this issue accurately, the boundary conditions of water and rock must be coupled in order to obtain the correct behavior of the collision area, which is the most important and complex part of simulation by theoretical, experimental and numerical methods. In this paper, the rock cutting with water jet is simulated using a SMOOTHED PARTICLE HYDRODYNAMICS method, which is a lagrangian numerical and meshfree method. For this purpose, firstly, the governing equations for fluid and solid are discretized with the help of the predictive-correct algorithm. Then, using the algorithm based on these equations, two-dimensional collision of water jet and rock and breaking behavior of rock are simulated. With this method, the depth and width of the cut can be determined at different speeds of the water jet and the optimal cutting speed of the stone is obtained. The results of the simulation have acceptable accuracy compared to the experimental results and shows that the SMOOTHED PARTICLE HYDRODYNAMICS method is a suitable method for the analysis of rock cutting with water jet.

This study aims to carry out a numerical analysis of hydrodynamic pressures on rigid structures caused by dynamic base excitation. First, the model for uid simulation is presented based on a numerical approach called SMOOTHED PARTICLE HYDRODYNAMICS (SPH) method. Then, the described model is used to measure the pressure exerted on rigid structures. In the performed analysis, the structures of di erent geometries (a rectangular tank with vertical sides, rectangular tanks with one inclined side of constant slope, and a cylindrical tank) are exposed to simple harmonic horizontal base excitations. The obtained hydrodynamic pressures on the sides of the tanks are compared with analytical and other numerical solutions.