scholarly journals Enhanced weakly-compressible MPS method for violent free-surface flows: Role of particle regularization techniques

2021 ◽  
pp. 110202
Author(s):  
Mojtaba Jandaghian ◽  
Abdelkader Krimi ◽  
Amir Reza Zarrati ◽  
Ahmad Shakibaeinia
Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1349 ◽  
Author(s):  
Mohammad Amin Nabian ◽  
Leila Farhadi

A Multi-Resolution Weakly Compressible Moving-Particle Semi-Implicit (MR-WC-MPS) method is presented in this paper for simulation of free-surface flows. To reduce the computational costs, as with the multi-grid schemes used in mesh-based methods, there is also a need in particle methods to efficiently capture the characteristics of different flow regions with different levels of complexity in different spatial resolutions. The proposed MR-WC-MPS method allows the use of particles with different sizes in a computational domain, analogous to multi-resolution grid in grid-based methods. To evaluate the accuracy and efficiency of the proposed method, it is applied to the dam-break and submarine landslide tests. It is shown that the MR-WC-MPS results, while about 15% faster, are in good agreement with the conventional single-resolution MPS results and experimental results. The remarkable ability of the MR-WC-MPS method in providing robust savings in computational time for up to 60% is then shown by applying the method for simulation of extended submarine landslide test.


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3189
Author(s):  
Abdelkader Krimi ◽  
Mojtaba Jandaghian ◽  
Ahmad Shakibaeinia

In this work, we develop an enhanced particle shifting strategy in the framework of weakly compressible δ+-SPH method. This technique can be considered as an extension of the so-called improved particle shifting technology (IPST) proposed by Wang et al. (2019). We introduce a new parameter named “ϕ” to the particle shifting formulation, on the one hand to reduce the effect of truncated kernel support on the formulation near the free surface region, on the other hand, to deal with the problem of poor estimation of free surface particles. We define a simple criterion based on the estimation of particle concentration to limit the error’s accumulation in time caused by the shifting in order to achieve a long time violent free surface flows simulation. We propose also an efficient and simple concept for free surface particles detection. A validation of accuracy, stability and consistency of the presented model was shown via several challenging benchmarks.


2016 ◽  
Vol 13 (04) ◽  
pp. 1641018 ◽  
Author(s):  
Zhenyuan Tang ◽  
Youlin Zhang ◽  
Decheng Wan

A multi-resolution moving particle semi-implicit (MPS) method is applied into two-dimensional (2D) free surface flows based on our in-house particle solver MLParticle-SJTU in the present work. Considering the effect of different size particles, both the influence radiuses of two adjacent particles are replaced by the arithmetic mean of their interaction radiuses. Then the modifications for kernel function of differential operator models are derived, respectively. In order to validate the present multi-resolution MPS method, two cases are carried out. Firstly, a hydrostatic case is performed. The results show that the contour of pressure field by multi-resolution MPS is quite in agreement with that by single resolution MPS. Especially, the multi-resolution MPS can still provide a relative smooth pressure together with the single resolution MPS in the vicinity of the interface between the high resolution and low resolution particles. For a long time simulation, the kinetic energy of particles by multi-resolution MPS can decrease quickly to the same level as that of single resolution MPS. In addition, a 2D dam breaking flow is simulated and the multi-resolution case can run stably during the whole simulation. The pressure by the multi-resolution MPS is in agreement with experimental data together with single resolution MPS. The contour of pressure field by the former is also similar to that by the later. Finally, the simulation by multi-resolution MPS is as accurate as the traditional MPS with fine particles distributed in the whole domain and the corresponding CPU time can be reduced.


2013 ◽  
Vol 842 ◽  
pp. 449-454
Author(s):  
Hao Wang ◽  
Qin Jiang ◽  
Chang Kuan Zhang

Mesh-free particle (Lagrangian) methods such as Moving Particle Semi-Implicit (MPS) are the latest generation of methods in the field of computational fluid dynamics where large interfacial deformations and fragmentations exist. Due to their mesh-free nature, these methods are capable of simulating any kind of boundary/interface deformation and fragmentations. In this study the weakly compressible corrected MPS (WCC-MPS) method is used to simulate dam break over a dry bed, which is a highly erosive and transient flow problem. The developed numerical model is first validated using a dry bed dam break problem by comparing with experimental data. Comparisons between the model results and experimental data showed that the developed numerical model with WCC-MPS method can well represent the dam break problems with very large free surface deformation and fragmentations.


Author(s):  
Akihiko NAKAYAMA ◽  
Wei Song KONG ◽  
Lap Yan LEONG ◽  
Khai Ching NG

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