Questions tagged [simulation]
Simulation is the process of mimicking the behaviour of a real physical process or system using a representative model.
210
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1answer
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Artificial Intelligence, Modeling and Simulation
Artificial Intelligence (AI) and its subsets i.e. Deep Learning (DL), Machine Learning (ML) etc. are becoming more and more ubiquitous in engineering, technology and science. Modeling and Simulation (...
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1answer
248 views
What kind of a researcher am I?
So far, I've worked a bit in modeling, simulations and simple lab experiments, and I've really enjoyed all three research methods to approach a single research question. I can write tricky (in terms ...
0
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1answer
125 views
How to visualize the vorticity / flow for a rigid body moving through a fluid?
How can I write down two-dimensional Navier-Stokes equations for a simple rigid object immersed in a flow and freely falling due to gravity? I'm trying to view the vorticity that's induced by the ...
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0answers
28 views
Tackling multiscale problem in numerical simulation
In a dusty plasma system there are more than one component with different masses, i.e, electrons, ions,neutrals and dust grains. Accordingly, there are more than one temporal and spatial scales ...
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44 views
Spectral solver on em-pic
I'm recently studying for the spectral solver to implement EM-PIC code. I read an article and have some questions.
Many PIC codes uses spectral solver to overcome numerical artifacts on FDTD.
In the ...
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1answer
50 views
How to get free energy surface of a 3d Ising Spin system using Monte Carlo simulation?
I am doing a Monte Carlo Simulation of the properties of a 3D Ising Spin system. I want to get the free energy surface of the spin system from the simulation. It is a magnetization vs free energy ...
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0answers
54 views
Stress during unloading in FEM simulation of an elasto-plastic truss element
I am simulating the behaviour of a single bar composed of two node points by fixing one point and applying a force on the oder node with $F_x = 1$ and fixing $u_y=0$. I am assuming the material to ...
2
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0answers
34 views
Decoupling of the fluid viscosity and incompressibility constraint in a partitioned scheme
I am new here and this is my very first question: I hope I respect all the criteria and rules.
I am just getting started with partitioned approaches for solving FSI problems. I am interested in a ...
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0answers
42 views
Why am I not getting the flat phase when Fourier-transform a Fourier-limited Gaussian pulse?
I have been trying to obtain a spectrum and a spectral phase of a Gaussian pulse using the Fast Fourier Transform provided with numpy library in Python. Here are ...
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2answers
80 views
What are the alternatives for ABAQUS in generating an *.inp file from a CAD model
ABAQUS gives a .inp file (in pre-processing stage) where the information with regard to the preprocessed model is defined, information such as geometry, mesh type, number of elements, boundary ...
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2answers
211 views
How to simulate over 1 billion particles?
I want to simulate human erythrocytes in capillaries. I calculated, that for a 1 meter long and 1 mm in diameter capillary there are about 3 billion blood cells.
Erythrocytes are actually discs, but ...
3
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1answer
91 views
Can one publish a new model and simulation without physical experiments?
When I read strong papers from, say, the Journal of Fluid Mechanics, a simple model, simulations and physical experimental results are given, showing good agreement.
Can one publish a new model and ...
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1answer
1k views
Conserving Energy in Physics Simulation with imperfect Numerical Solver
I am creating a C++ Physics Simulation where I need to move an rigid body through an acting force field.
Problem: simulation does not conserve energy.
Quesiton: abstractly, how is conservation of ...
2
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0answers
56 views
Processing time steps in chunks with Fortran [closed]
My PDE simulation program written in Fortran has to make about 2 million variable time steps. But with each time step it slows down more and more, so that if it initially makes 1000 time steps per ...
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0answers
23 views
How to simulate a PDF using data samples like this?
I know two methods to simulate a PDF from random data samples using MATLAB :
1) Using a histogram where I use this command
histogram(data,'Normalization','pdf'), it gives PDF like bins.
2) Another ...
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0answers
36 views
How to avoid density getting “deleted” in two way rigid body coupling with LBM CFD?
I've been reading this paper recently, which talks about using Lattice Boltzmann methods and two way coupling. Specifically, it outlines fluid solid coupling, and solid fluid coupling, and how simply ...
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0answers
123 views
Is a complete bacteria simulation with an exascale supercomputer possible?
Will it be possible to simulate a complete (at least simple) bacteria atom by atom on an exascale supercomputer? or is it possible already today with the largest systems?
Here, I've read that ...
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0answers
59 views
Using MATLAB to simulate the Ising Model
I am using MATLAB to simulate a 1D Ising Chain. I am running into an issue where when trying to find heat capacity, my system has a tremendous amount of noise. I'll post my code and an image of the ...
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1answer
50 views
Smoothed Particle Hydrodynamics: Weird clustering of particles. Is that normal?
I implemented a rather simple SPH simulation using a cubic-spline-kernel and a simple non-iterative pressure solver as described in this PDF in equation 9. I followed algorithm 1 of that paper (...
12
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2answers
418 views
What guidelines should I follow for simulation software projects?
I am not sure whether this question belongs here, but I would like to give it a try and benefit from the experience of the people at scicomp.SE.
From my experience, the software quality in ...
3
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1answer
77 views
Computing autocorrelations of configurations in Monte Carlo simulations
In the context of Monte Carlo simulations, I am trying to learn how I should ensure that the configurations of my system are not correlated for the chosen interval of measurements. I have found out ...
2
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1answer
125 views
Why don't we call the simulation “a model for …”?
When a set of model equations, e.g. some coupled differential equations, has solutions that behave in ways similar to real-life phenomena such as blood flow in the heart, a wave movement, or a plate ...
3
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1answer
92 views
Calculating the Convolution Using DFT (FFT)
I have the following convolution as part of a numerical simulation.
$$T(r)=\int \mathrm{d}^3r_2\, p(r_2)f(r_2)\alpha(r-r_2)\, .$$
My problem is that the analytical expressions for $f$ and $p$ do ...
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0answers
70 views
How one can simulate a system given by differential equation?
I want to simulate a diffusion environment given by the differential equation
$$\frac{\partial u(x,y,t)}{\partial t}=D\left(\frac{\partial^2 u(x,y,t)}{\partial x^2}+\frac{\partial^2 u(x,y,t)}{\...
2
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0answers
40 views
What is the best methodology for physics simulators of large floating base rigid body systems?
I want to implement a physics simulator for large floating base rigid body systems from scratch. The Rigid Body Dynamics Systems (RBD) should typically have the following characteristics:
About ~50 ...
0
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0answers
48 views
Simulate friction arround steady-state point
When simulating a friction dynamic system, I have come to a problem when approaching steady-state.
In the example below, a box moves along a surface with a certain friction coefficient:
...
2
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1answer
65 views
Plasma Simulation Software Advice?
Iām looking for software that can simulate āhotā plasmas of multiple ion species...so some sort of simulation software that could calculate ion temperature and density distributions taking into ...
0
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1answer
33 views
How to implement the Impulse Based Dynamics for the rigid body dynamics simulation?
I am having hard time learning the method of impulse based dynamics developed by Mirtich for rigid body dynamics simulation. Please help me out if any body has any example code(algorithm) of it. ...
2
votes
1answer
71 views
Symplectic linear multistep method?
I'm doing a gravitational n-body simulator and I'm thinking of implementing linear multistep methods like Adam-Bashforth. But is there any symplectic multistep methods?
5
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2answers
122 views
Is saying “math modeling and numerical simulation” wordy and redundant?
I'm describing some work on my website, and I'm wondering if my math modeling and computer simulation work is described ok: I say
math modeling and numerical simulation.
Should I say "...
3
votes
2answers
101 views
Optimization techniques for expensive multi-variable functions
I'm working with a finite element model in which I'm interested to minimize the average temperature at a surface. I have 15 independent variables in my model, including geometry, materials, flows, ...
1
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1answer
52 views
Harmonic oscillators with periodic boundary conditions
I am trying to simulate multiple harmonic oscillators in periodic boundary conditions (subsequently visualizing the process in VMD). I have successfully simulated multiple HOs by using the Leapfrog ...
1
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1answer
160 views
Can OpenFoam be used for interactive simulations (flying a plane)?
I'm a software engineer and I've just started to fly rc-planes. I'm currently building a self learning auto-pilot for my plane and I'm really interested in CFD. I installed OpenFOAM and ran through ...
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1answer
46 views
How to choose the parameters for a collision free comet trajectory
I implemented a simple simulation of a comet flying through space being deflected by the gravity of randomly generated planets for art purposes. My problem with that simulation is, that there are many ...
0
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1answer
31 views
Software for cellular automota
I would like to do simulations using cellular automata to describe the behavior of influenza. What software do you recommend?
0
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1answer
64 views
Simulating Brownian motion in 3-D for first hitting time?
I want to simulate Brownian motion in 3-D for the following conditions:
$$p(x=0,y=0,z=0,t=0)=1$$
$$p(x,y,z=c,t)=0$$ where $p$ is the probability of finding molecules in the 3-D environment. I want to ...
3
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1answer
63 views
Radiation heat transfer between surfaces
I'm trying to model the temperature distribution over a curved surface. Apart from the heat equation, I need to take into account the energy emission/absorption through electromagnetic radiation. The ...
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1answer
68 views
Writing parallel code for molecular computation [duplicate]
I recently moved towards computational biophysics from an experimental science background. As of now, I am learning the fundamentals and doing some basic monte carlo simulations of LJ fluid on my ...
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2answers
128 views
Custom exponents for Lennard Jones in LAMMPS
I am trying to run an MD simulation using this generalized version of Lennard Jones.
$$
U(r) = \left(\frac{r_0}{r}\right)^A -\frac{A}{B}\left( \frac{r_0}{r} \right)^B
$$
However, I do not know how ...
3
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2answers
766 views
How to simulate basic semiconductor models using the Drift-diffusion model on Python?
I'm trying to simulate basic semiconductor models for pedagogical purposes--starting from the Drift-diffusion model. Although I don't want to use an off-the-shelf semiconductor simulator--I'll be ...
1
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1answer
87 views
Multi-steps method for Navier-stokes equations with strongly nonlinear diffusion
I am trying to solve a particular form of the Euler / Navier-Stokes equations in 1D, with very strong and non-linear diffusion coefficients.
My system of equations is
\begin{cases}
\...
5
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0answers
107 views
How can Navier--Stokes equations have asymmetric solutions such as Karman vortex streets
The Navier--Stokes equations are axially symmetric, so with symmetric boundary conditions, how can features such as Karman vortex streets develop?
I understand that in reality symmetry does never ...
8
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1answer
204 views
What scientific problems can be simulated that couldnāt be simulated 10 years ago?
What scientific problems can be simulated with computers that couldnāt be simulated 10 years ago?
Iām particularly interested in cutting-edge scientific simulations, which wouldnāt have been possible ...
0
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1answer
97 views
Simulation-based Optimization vs PDE-constrained Optimization
What is the difference between Simulation-based Optimization and PDE-constrained Optimization?
Would studying a text on Simulation-based optimization be sufficient to understand and apply both?
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1answer
44 views
What are the things I should keep in mind before doing an analysis of my gromacs simulation?
I did a liquid argon simulation at 100k. I forgot during analysis that I need to accommodate for the Periodic Boundary Conditions before doing any analysis which included distance. What are other such ...
0
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1answer
58 views
Barnes-Hut method for gravitational dynamics
I have an assignment where i got this definition - "The dots velocities following the Maxwell distribution with typical velocity of $$v=<v>^{\frac{1}{2}}$$ and that mean that each of the ...
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2answers
173 views
Effective way to build the neighbor's list in MD
I'm trying to implement the following form of the cell/neighbor list method in my MD code. I have divided my simulation box into a fixed number of cells, and according to its positions, I have ...
2
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1answer
137 views
build a simple incompressible solver with spectral method
I am trying to build a simple solver for the incompressible fluid in a periodic box to learn the spectral method. I am following the textbook (Peyret R. Spectral methods for incompressible viscous ...
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2answers
638 views
reading and processing large GRIB files
I'm trying to convert and process GrADS (grib) files into netcdf files. The files have values every 3 hours (2890 per year), 12 z levels, 120 variables, 241 columns and 236 rows. The data is almost 80 ...
2
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1answer
456 views
MD Simulation: Reference for the Neighbor's List Method
With a rather basic knowledge in C++, I have written my own MD simulation code. Currently, I calculate forces in the most naive way: I go through all the atoms and account for their interactions. This ...
