We’re rewarding the question askers & reputations are being recalculated! Read more.

# Questions tagged [simulation]

Simulation is the process of mimicking the behaviour of a real physical process or system using a representative model.

194 questions
Filter by
Sorted by
Tagged with
155 views

### Value of density when there are no or very few neighbours in SPH simulation

Sorry for the noob question. I am trying to implement SPH using the directions shown in this paper. The density needs to be updated using the formula The smoothing kernel is If there are no ...
91 views

### Tracking the speed of 2D oscillations on a lattice

I wrote a Monte Carlo simulation of the 2D Lotka-Volterra model on a discrete lattice (with periodic boundary conditions). A video that I produced (which images the system after some number of monte ...
89 views

### Is it normal to expect the error of simulation of a damped harmonic oscillator to decrease as the damping factor decreases?

I am simulating a damped harmonic oscillator using the RK4 method of numerical integration. I am comparing the simulated results with the analytical ones (for the free evolution case) and obtaining ...
145 views

### Poisson solver diverged

My 2D-Poisson solver is build for simulation of semiconductor. The algorithm is Gauss-Seidel iterative method. If I use simple PN junction for simulation testing, it diverged while I applied high ...
1k views

### What are the differences between CFD simulations and realistic ocean/atmosphere model simulations?

The field of computational fluid dynamics (CFD) is dedicated to solving the Navier-Stokes equations (or some simplification of them). A subset of CFD, ocean and atmospheric models numerically solve ...
1k views

### Using Trilinos and/or Petsc in Windows with Visual Studio?

I am currently working on a project of building a simulator. Up till now I have mostly played around with very simple examples, but with regards to the future I have been thinking that it might be a ...
109 views

### Confusion in modeling and computing [closed]

I come from a computer graphics background without any professional in computational science. But I find my job(game engine development) being related to this field. May I ask some general questions ...
1k views

### Numerically solve a PDE in Python with a term calculated by coarse-graining

I'm trying to solve a PDE in Python of the form, $\dfrac{\partial c(\mathbf{x}, t)}{\partial t} = \mathrm{D} \nabla^2 c(\mathbf{x}, t) -\gamma \rho(\mathbf{x}, t) c(\mathbf{x}, t)$ where $c$ ...
114 views

### Simulating interaction of Smart Fluids with Solids

Is it possible to simulate interaction of Smart Fluids with Solids? Is there a software capable of doing so? What I Know: The two software that I know of are Autodesk Simulation Mechanical and ...
332 views

### Lagrange Multipliers in Multi-body Finite Element Code

I'm working on a Multibody dynamics code using the finite element method to simulate the behaviour of flexible beams (using this paper if anyone is interested/ it is relevant). I'd like to model ...
222 views

### Which processor should I consider buying for a desktop built for scientific computing?

I run Python/C simulations for biological problems, so the range of computational tasks can be broad. Here are some examples: 1) continuum model simulations: FEM type 2) agent-based simulations: ...
60 views

### Iteratively refine bounds on exp for Metropolis criterion

In Monte Carlo simulations, using the Metropolis criterion, one often has to compare a random number $a$, $0 \leq a < 1$, to the Boltzmann distribution $exp(-\beta\Delta E)$, where $\Delta E$ is ...
68 views

### Particle Collision to Static paticles

I have a system of particles with equal distance with each other and another at random positions which is moving with time. I want to know: a) The method by which I can reduce the number of particles ...
487 views

### PyOpenGL/OpenGL Generating Cosmic NBodys

I am working on a Universe Simulator. I'm stuck on creating the dark matters webs of the universe that look like this: http://www.mpa-garching.mpg.de/galform/data_vis/sim3dnew-highres.png I am ...
421 views

### How can I create a computational model of the human eye?

I need to create a program that can simulate the optical system of the human eye. The input will be any image, the output would be the image that is projected onto the retina. I need it to be as ...
961 views

### Implementation of Navier-Stokes Equation for Ocean Waves

I am doing an undergraduate research to model ocean waves in shallow waters in real time. I am trying to base my research on Navier-Stokes equations since they produce the most accurate mathematical ...
193 views

### Removing non-determinism from molecular dynamics code

I've been looking through the other answers, and I haven't found a good answer yet. I'll describe the simulation I am running, and then the problems. The program simulates particles undergoing ...
176 views

### What scale problem can be simulated on an PC using Smooth Particle Hydrodynamics?

I want to simulate tidal features in a large body of water using was smooth particle hydrodynamics. For a system composed of an incompressible fluid, what general scale of problem can be tackled with ...
116 views

### Algorithms for adding hydrogens on a molecule

I want to add hydrogens to some linear polymer molecules (polyethylenes). I know some working methods like using PyMOL internal function h_add. This method works, but hydrogens are added at distances ...
167 views

### Is it possible to simulate fluid dynamics in a time-based and deterministic manner?

The Problem Domain I have a number of network-connected PCs. I want to be able to simulate and replicate the same simple fluid dynamics simulation (E.g. Navier-Stokes), in real-time, between them. ...
407 views

### Why do the shape of finite elements matter?

I have used FEA for a couple of years now, but using it and using it correctly are two different things, safety factor is not the solution to everything. I have the feeling I won't be using it right ...
180 views

### Efficient Gravitational Field Implementation

I asked a similar question on physics.stackexchange, being ignorant about this website. I am basically looking for an efficient way to implement gravitational fields. I have a huge 2D space, with ...
54 views

### Discretizing boundary conditions for vortex methods

I am working on a fluid simulation using vortex methods. For this I must compute the vortex sheet on my boundaries given as:  \gamma(\mathbf{x}) - \frac{1}{\pi}\int_S \frac{\partial}{\partial\mathbf{...
904 views

### Euler's equations for a tube with varying cross-section

$\def\pd{\partial}$ $\def\l{\left}\def\r{\right}$ $\def\mdot{{\dot{m}}}$ $\def\eps{\varepsilon}$ Consider a tube with longitudinal coordinate $x$ from $0$ to $l$ and varying cross-section $A(x)$. ...
2k views

### Monte Carlo estimation of Pi with Buffon's needle

Is there a way of estimating Pi with the Buffon's method without assuming Pi known? To be more precise: in a Monte Carlo simulation of the experiment invented by Buffon I would (ideally) generate 2 ...
1k views

### Celestial mechanics simulation software? The 'N-Body Problem'

What software or sites might simulate an N-body gravitational problem? Application is related to Klemperer Rosette or Iridium Satellites. Bias for C, C++, PHP, or Java. Nice visuals a big plus. ...
98 views

### Tracking for two meshes

I'm dealing with physical simulation (position based dynamic). Now I'm trying to realize tracking for two meshes. In order to explain what does it mean, let's assume that we have two similar meshes: ...
95 views

### Barnes-Hut algorithm and recursion limit

If while distributing particles to their corresponding nodes, two particles comes closer to a level smaller than the machine precision (or $\Delta d \to 0$), how is the situation to be treated? Should ...
481 views

I have a problem with parallelization and the brownian dynamics (molecular dynamics) code that I am using. We have our own home-grown framework at the university, and recently we've made the change ...
184 views

### Solving system of differential equations with interconnected boundary conditions

I am trying to solve the following system of differential equations numerically over the domain $x=0$ to $x=D$. The main difficulty is that the boundary conditions are interconnected and depend on the ...
550 views

### Sorting eigenvalues by the dominant contribution

[Edited to simplify the question] I am trying to associate the eigenvalues $E$ of a matrix $H$ to the original rows of the matrix. Moreover, it would be trivial to sort the eigenvalues in ascending ...
512 views

### Simulating advection over a network of 1D pipes

I am trying to create a simulation to help visualize how different chemical components flow through a network of pipes with associated valves, pumps, and chemical inputs. In this simulation, the pipes ...
52 views

### Calculating the number of molecules diffusing out of a volume [closed]

I have a system of reactions that are governed by differential equations. They are reacting inside of a volume with known dimensions i.e lbh. I don't have any other information on their position ...
965 views

### Particle Tracking Code - MATLAB vs. C++

First some background, I am a mathematician by training with very little formal training in programming. I am most comfortable in MATLAB and have been working with it for a long time. My second choice ...
108 views

### Detect rigid body motions in a cloud of points

This question popped up today in our group meeting. Suppose you are given a cloud of N points in 2D and each is associated with a velocity vector. These points are associated with particles on a 2D ...
230 views

### N-body simulation for particles

I would like use N-body simulation for measure a torque on an object in a liquid (helium). It's a 2D study. On the site : http://www.browndeertechnology.com/docs/BDT_OpenCL_Tutorial_NBody-rev3.html I ...
229 views

### Sound Waves Simulation in 3D Environment

I want to do a simulation of sound waves including wave propagation, absorption, and reflection in 3D space. I did some research and I found this question in stackoverflow but it talks about ...
2k views

### Best PARALLEL numerical solver of first order differential equation

I have a system of 256 differential equations that I want to solve numerically. The system represents the Liouville equation, which is a first order, linear differential equation with complex numbers. ...
896 views

### Feasibility and software for acoustic simulation

I'm looking at doing a finite-element simulation of air flow essentially for the purposes of approximating the response to an external audio impulse of a smallish (~10-30 cm scale), stationary 3D-...
167 views

### How can i find the coordination number with voro++? [closed]

Could anybody please help with voro++ cause i am new to this software?My problem is how can i find the coordination number of an atom ,cause i checked it for a bcc lattice and it gave me 24 for all ...
223 views

### Non-deterministic/probabilistic molecular dynamics simulations

I'm looking for a piece of software for performing molecular dynamics simulations with the following specifications: required: well published (as in there are papers citing it in one or more ...
88 views

### numerical inaccuracy ellipsoid-ellipsoid collision

I am trying to implement ellipsoid-ellipsoid collision in my C++ code. Briefly this task can described as next: Let's assume that we have two arbitrarily oriented ellipses in the in space and this ...
112 views

### What are the governing equations solved in coupled atmosphere-ocean models?

In (hydrostatic) atmospheric general circulation models, for example the so-calle Primitive Equations, consisting of the horizontal momentum equation, the hydrostatic balance, the continuity equation, ...
874 views

### Is Discrete Exterior Calculus currently a focusing point in numerial computing world or simulation in industry,

I am just wondering if Discrete Exterior Calculus, as a new numerical method , is good at numericall solving problems in elasticity, fluids or other physical/real area.
140 views

### Simulating the motion of a elastic body under gravity [closed]

I am doing a numerical simulation of a elasticity problem. It is very simple. A cuboid elastic body with the right end fixed on the wall, under the gravity(but here I set it to be 1 along the z-axis ...
810 views

### Any note on Immersed boundary finite difference method?

For parts of a talk, I need a note on "Immersed boundary finite difference method", mainly about the reason of appearing this branch in the finite difference methods, considering mathematical ...
537 views

### Finding a molecular dynamics visualization library for C

I asked this question over at stackoverflow, and got blasted for it. I am currently working with legacy MD code written in C that my university uses, and haven't moved to a more modern library like ...
158 views

### Simulate aerodynamics of a general shape object

I'm trying to code a simple physics simulator in C++ but I'm stuck on the air resistance issue. Surfing the Internet I only find a drag coefficient for very basical area shapes when the air is ...