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2
votes
2answers
86 views

how to simulate a steep potential barrier in langevin equation

When simulating a Langevin equation, how is a vertical potential barrier handled? I have the time overdamped evolution of the position $x$, described by $\gamma\frac{dx}{dt}=-V'(x)+\eta(t)$ where $...
0
votes
0answers
11 views

Is it posssible to numerically simulate a metal layer the same way as a semiconductor one

I need to simulate a schottky junction device. Unfortunately, the software for simulation (AFORS-HET) doesn't allow adding metal (I need to simulate aluminum contact) layers (but it allows to add "MS-...
0
votes
0answers
142 views

Simulation software for wave optics

I am using COMSOL multiphysics Optics module for wave optics simulations and I am wondering if there is better simulation software for wave optics simulations (no multiphysics needed). Like software ...
0
votes
0answers
37 views

Does the heat capacity play a role in a steady-state thermal simulation?

I'm confused... In a steady-state thermal FEM simulation with several solids (different materials, with non-linear behaviour) and first and second order boundary conditions, is it necessary to to ...
2
votes
2answers
114 views

Center of mass chaotic in n-body gravitational interactions?

I wrote a gravitational particle simulation. To prevent the particles flinging off out of the screen, I added a bit of friction (it also makes the animation prettier as particles spiral into one ...
4
votes
1answer
121 views

What boundary conditions in a wave simulation would avoid reflections?

In simulating an elastic medium as a series of mobile points connected by ideal springs, it's straightforward to model conditions corresponding to a fixed endpoint, which results in an incoming wave ...
2
votes
1answer
321 views

Simple QFT simulation - how to do it

I would like to write a simple QFT simulation for a free scalar field with a cubic interaction term. However, I got stuck a bit. I will try to describe what I think I understand. I want to have a ...
0
votes
2answers
87 views

Molecular Dynamics simulation question

In molecular dynamics simulations you apply and solve Newton’s equations of motion for a set of atoms to obtain real dynamical information on how individual atomic positions change as a function of ...
0
votes
0answers
19 views

Evaluation of width function; thermal neutron scattering cross section

I am attempting to perform some molecular dynamics simulation, based off of this paper, and do not have the slightest clue how they evaluate the width function (Eq. 4). My attempt at figuring it out/...
0
votes
1answer
46 views

Avoiding a singularity in the simulation of a spherica pendulum

I didn't know whether to put this here or in StackOverflow - so I open to answers just telling me to go there! I am looking to simulate the motion of a spherical pendulum. The Lagrangian is $$ \...
0
votes
1answer
119 views

Trajectory of a projectile in a three dimensional space [closed]

$g$: the gravitational acceleration—usually taken to be $9.81\:\mathrm{m/s^2}$ near the Earth's surface $θ$: the angle at which the projectile is launched $v$: the speed at which the projectile is ...
0
votes
1answer
87 views

Coding Newton's Laws into C#. Having trouble determining the order of finding what I need

So I'm in high school, and I'm currently in AP Physics 1. We're currently doing Newton's Laws where we draw free-body diagrams and use all the various forces (Tension, friction, weight, that kind of ...
1
vote
1answer
71 views

Physics of wheel slip?

I am trying to write a program that simulates the physics of a locomotive (diesel, not steam). I already have a method to get the tractive effort of the locomotive. If anyone must know, the one I am ...
0
votes
1answer
85 views

How to model the mixing of two fluids?

In the context of a research project of mine, I am faced with the difficult task of modeling the mixing of two fluids in a container. I would like to achieve the following: Given a container (...
1
vote
1answer
69 views

Units in gravitational N-body simulations

I use a code in Python to simulate a binary system interacting through gravity. You can find it here; The code works fine. I am however having problems with the units of length and velocity. I ...
2
votes
2answers
108 views

Limitations of particle in cell method for high desnity plasma

Are there any limitations of particle in cell (PIC) method for high density plasma? To be more specific, is modelling of a narrow channel of high density plasma possible or are there any limitations ...
0
votes
1answer
84 views

Is it possible to understand physics and make new discoveries using computer simulation? [closed]

I'm a computer science major and I want to learn Physics. I can create computer simulations of any type. I'm not good at math that is required to learn QFT or GR,but I'm thinking is it possible to ...
9
votes
3answers
3k views

What happens if you slow down a moon?

Let's say you'd put a whooping big rocket engine on the surface of the moon, and slow down its orbital velocity. Not to a complete stop, mind you. Just a bit slower than it was going before (a couple ...
1
vote
1answer
115 views

How do I calculate the effect of a prograde, retrograde, radial and anti-radial burn on the orbital elements of a two-dimensional orbit?

My relevant knowledge: This question works in two dimensions, with a two-body problem (see bottom for context). To my understanding, a two-dimensional orbit has the following orbital elements (3D ...
3
votes
2answers
57 views

Can I identify phase (solid, liquid, gas) just from a snapshot of molecule positions?

Suppose I have a simulation of a bunch of nitrogen molecules (N_2). Just by looking at the positions of a bunch of the molecules in a volume of space, how can I tell whether the picture is showing a ...
2
votes
2answers
143 views

Simulation of everyday life based on standard model [closed]

If I were to model the standard model, say on a super powered computer (which does not necessarily have to exist in the real world), would I get molecules, chemistry, life? I want to understand the ...
0
votes
3answers
53 views

Multi-Force Lift

Background: I am creating a 3D game. A ship has 3 thrusters that apply force up (Z+) to counteract the force of gravity (Z-). I am trying to figure out how much thrust to apply to each thruster to ...
-1
votes
2answers
85 views

What is the output of a simulation of quantum particles? [closed]

When physicists simulate a quantum system, what is the output of such computation? Is it the probability wave function of the system? What if the system consists of enough particles to be considered ...
2
votes
0answers
25 views

Initial conditions for a massive objects to follow a path

Suppose I have a path, such as the one traced out by $r^2 = \cos(2\theta)$, and $n$ objects with mass $m$ at equidistant points on this path. What velocities should each object initially have in order ...
0
votes
2answers
197 views

Must-know topics for Computational Fluid Dynamics (CFD)

My undergrad major was Electrical Engineering. My MS thesis is related to simulation of hydrogen movement in a complex geometry. I did take a course on Fluid Dynamics but I have to say it wasn't one ...
2
votes
0answers
55 views

Simulation of oscillator with frequency dependent damping

What would be the equation for the frequency dependent damping of harmonic oscillator? Is there something like: $$ \ddot{x}+2\delta\dot{x}+\omega_0^2x = \frac{F}{m}f(t) $$ with frequency dependent ...
0
votes
0answers
19 views

Setting up initial configuration of a Micelle - Molecular Dynamics

I have just started learning Molecular Dynamics using dl_poly_classic and analysing trajectory using nMOLDYN. Our primary aim is to do neutron scattering, but however we do Molecular Dynamics to ...
2
votes
1answer
199 views

Problems implementing Lattice Boltzmann method

I want to make a basic 2D implementation of the Lattice Boltzmann method (in javascript) to simulate gas/fluid flow, but I have run into some problems and I can't seem to find the cause of it. ...
0
votes
2answers
147 views

How Much Computing Power would be Required to Fully Simulate a Cubic Meter? [closed]

Imagine you want to simulate a cubic meter down to the particle. By following the Standard Model and other basic physical equations, how much computing power would be required to do this, in say, a ...
3
votes
1answer
71 views

Precise definition of Jet Energy Scale and Jet Energy Resolution

I've been struggling to get the precise meaning of these two quantities, is it correct to say that the first one is only related to Montecarlo simulations? I can't seem to find a pedagogical ...
0
votes
0answers
101 views

Path Integral Simulation

I am trying to do a simulation with path integrals. I previously simulated with a step potential by time evolving the eigenvectors of the Hamiltonian. See code and video. Notice is is a bit weird, ...
7
votes
1answer
246 views

Converting between $\frac{d \sigma}{d t}$ and $\frac{d \sigma}{d \Omega}$

I'm performing some simulation where I require the integration of a cross section of the form $$\sigma = \int_{-s}^{0}dt \frac{1}{(t-\mu^2)^2} f(\theta,\phi)$$ where $s$ and $t$ are the usual ...
0
votes
0answers
85 views

Position and Tension of Kite/Balloon Tether in Presence of Wind

I wish to solve for the position of a kytoon's (hybrid kite and balloon, with both aerostatic and aerodynamic lift as well as non-negligible drag) tether given the forces present on the kytoon and ...
0
votes
1answer
49 views

How does Parallel tempering work for optimisation procedures?

Markov Chain Monte Carlo procedures can be used in global optimisation procedures. Parallel tempering is a particular type of stochastic sampling, but how does it work?
0
votes
1answer
73 views

Clarification of the physics involved of an orbiting body in a circular orbit

I am writing a physics simulation program to simulate a body orbiting a planet but I am a little confused about the physics involved and would like some clarification. To simulate gravity I am using ...
2
votes
1answer
99 views

Is the $\mu VE$ ensemble possible to formulate?

I have recently learned about ensembles in statistical mechanics, and I've seen multiple applications and interpretations of the EVN (microcanonical), TVN (canonical), $\mu$VT (grand canonical) and ...
2
votes
0answers
66 views

How to let Pythia to output the complete event record in LHEF or StDHep format?

I am currently using Pythia 6.4 to simulate some processes (I do not have the intention to upgrade to 8). Now, I need Pythia to output its event record in the format of LHEF or StDHeP. I accidently ...
-3
votes
2answers
163 views

The Simulation Hypothesis As A Theory Of Everything [closed]

I have long found the Simulation Hypothesis to be better-able to answer questions that I have regarding the universe than the string theory and the quantum field theory. What I believe is that the ...
0
votes
1answer
55 views

Evolution of dark matter and gas temperature

So I have recently watched a simulation of dark matter density and gas temperature evolution in a universe. However I couldn't find description of under what assumptions it was was made and what it is ...
2
votes
0answers
197 views

3D Simulation Software

I need a software capable of simulating the physics of a car going off a ramp. This is a stunt that I will be attempting and looks like the following: A car, going off a curved ramp, doing a barrel ...
3
votes
1answer
186 views

Critical temperature and lattice size with the Wolff algorithm for 2d Ising model

When I run my implementation of the Wolff algorithm on the square Ising model at the theoretical critical temperature I get subcritical behaviour. The lattice primarily just oscillates between mostly ...
0
votes
2answers
95 views

Simulation of a simple robot [closed]

I'm a programmer and I'm working on a simple robot simulator. Of course, the most important part of this simulator, is the physical simulation of the robot. Unfortunately, I have a little knowledge ...
0
votes
0answers
15 views

Optics Simulation Software for Airy Beam Generation [duplicate]

I have been trying to simulate the generation of Airy Beams using a simple two-cylindrical lens setup as shown by Papazoglou et al. http://journals.aps.org/pra/abstract/10.1103/PhysRevA.81.061807 I ...
4
votes
4answers
309 views

How can I add dark matter to my $N$-body simulation?

I've written a simple non-scientific N-body simulation for fun: http://magwo.github.io/fullofstars/ I expected to create something looking like spinning galaxies (there are two invisible very heavy ...
2
votes
1answer
58 views

Ewald summation without repeating one particle periodically?

I need to perform an Ewald summation for a Brownian Dynamics simulation. In the normal Ewald summation procedure, all particles in the simulation box are periodically repeated in the neighbouring ...
0
votes
1answer
38 views

What velocity do I need to get the moons orbit perfectly aligned with the earths center [closed]

I have a simulation for universal gravity with two objects. How can I calculate the velocity or instantaneous force I would need to apply to object 2 (the moon) to get it to orbit so that the origin ...
1
vote
0answers
91 views

Do I need a particle to simulate a particle? [closed]

Edit TL/DR Is an assumption of the theory that the universe is a simulation that the simulating universe is fundamentally more complex than our own? The Long Version As a programmer, I find the ...
2
votes
1answer
52 views

How does phonon scattering change the distribution function?

For a one-dimensional structure, we know that the modified distribution function has the following energy dependency in equilibrium: \begin{equation} Z(\varepsilon)\,f(\varepsilon) = \dfrac{N_\text{1D}...
3
votes
2answers
217 views

Why is my Lyapunov exponent similar for single and double pendulum?

This is my first question here on stackexchange. I hope that I can be understood. If not, tell me and I will reformulate and fill in with details. I have simulated a single pendulum and a double ...
1
vote
1answer
115 views

Difference between Enzo & Gadget astronomy simulation codes

Enzo and Gadget are simulation codes used in astronomy. What are the largest differences between them both in terms of physics they simulate and in their implementations?