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Keplerian orbits and radial velocities: problem with true anomalies

I am writing a pure Python code to calculate radial velocities of stars with massive objects orbiting them. I am following the formalism from Murray & Correia (2011) (hereafter MC11). In a given ...
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19 views

2-D Ising model temperature of equilibrium [duplicate]

I have simulated 2-D Ising model in C#, but my scatter plot for magnetization versus temperature is an decreasing line (you know that the correct plot decreases quickly in a temperature near 2.3). I'...
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27 views

Why is more difficult for a DFT to converge with non-periodic conditions?

I am simulating a cubic amorphous silica system. When all boundaries are periodic the SCF iteration converges rapidly. However, when the boundary is not periodic in the $x$ direction, the SCF ...
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12 views

Parameters for modelling 4 level 2 electron gain medium for laser

I have an EM simulator that can model laser gain medium by a 4 level 2 electron system. However the model requires pumping wavelength, lasing wavelength, pumping linewidth, lasing linewidth, decay ...
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39 views

use FEMM to simulate electric field for a magnet inside a coil

I'm trying to simulate a magnet inside of a coil of wire, with and without current running through the wire. I'm using the free FEMM software to try to simulate this, but I don't think i'm setting ...
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12 views

Why does SCF convergence on DFT worsens for a parallelepiped domain?

I am currently simulating parallelepiped domains of amorphous polyethylene with DFT. I would like to know the reason why the convergence of SCF worsens when the domain is not cubic. Does the k-point ...
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1answer
39 views

How to simulate an accelerometer in code

I want to write a simulation of an accelerometer (with a fixed X and Y axis in this case but with respect to a world coordinate frame) on a stick, rotating in a circle around a fixed point. From that ...
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37 views

How to calculate the forces that create precessing motion of a spinning top?

I'm trying to create a a spinning top simulation, and I have a problem with simulating the precession. I read the Wiki article about precession, which have the formula for angular velocity of ...
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1answer
25 views

Calculating true anomaly of a hyperbolic trajectory from time

I'm creating a simulation for orbiting bodies with my primary challenge being calculating the true anomaly of a trajectory with respect to time. I have figured out circular, elliptical, and parabolic ...
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20 views

How to find positions in the equilibrium state of mass-spring system?

I've simulated 3D mass-spring system (mesh/network). First the system was in equilibrium state of it own (called state {A}). If I moved some of the masses in the system to the new positions, the ...
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1answer
54 views

Cavity resonator modelling and simulation of em fields inside the cavity

I want to model a cylindrical cavity resonator and study the different modes of em fields inside it using MATLAB/COMSOL. Please refer me books/articles or other resources so that I can achieve my goal....
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1answer
75 views

Newtonian Gravity Simulator?

Could anyone suggest me a good (and possibly free) Newtonian Gravity Simulator software available on the web, where it might be possible to simulate the Solar System dynamics and playing with it, by ...
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1answer
31 views

Setting up initial conditions of parabolic orbits, centre of mass frame

I am writing a simulation of 2 bodies in coplanar parabolic orbits in their centre of mass frame (in C++) and am having difficulties setting up the initial conditions for the velocities. The total ...
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39 views

Can a simple harmonic oscillator describe Rabi oscillations?

I've been trying to simulate a resonant laser oscillation of a two level atom with Rabi frequency $\Omega$ and a rate of spontaneous emission $\Gamma$. So the wavefunction would be $\mid \Psi\rangle = ...
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66 views

Moment of inertia tensor of cube with objects inside

I'm currently trying to write a simulation that, essentially, calculates the moment of inertia of a hollow cube in 3D, where it's possible to attach additional cuboid shapes inside of it - to see how ...
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1answer
56 views

Detailed balance of an energy function

I'm having difficulties understanding a problem about the acceptance rules for a given energy landscape. The Problem Suppose a system in which the energy is a function of x only: $$ e^{-\beta U(x)} =...
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64 views

Which formula was used to get Gravitational Waves animation?

I would like to make animation like this by myself It is from wikipedia article "Gravitational wave". But if I use formula from wikipedia article "Gravitational wave" subsection "7.2.2 Wave ...
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63 views

Rolling Resistance Coefficient

I found that rolling resistance can be expressed with this equation: $$F_\mathrm{rr} = \frac{C_\mathrm{rr} W}{r}$$ Where $C_\mathrm{rr} =$ coefficient of rolling resistance $W =$ normalforce $r =$...
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10 views

Simulation of circulation on pavements between walkers and unicyclists

I am a fan of electric unicycle. I am interested in the interaction between electric unicycle and foot-walkers. The question here I would like to answer is: is it dangerous to mix on a pavement, ...
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1answer
57 views

What is the best software to simulate the tracks of muons in matter?

What is the best (free) software to simulate the tracks of muons in matter? I have done some simulations using SRIM/TRIM (www.srim.org) by modifying their proton model to have the mass of a muon, but ...
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17 views

Explicit solvent simulations in NVE ensemble: Molecular Dynamics

I am simulating a SDS micelle system in NVE ensemble at room temperature. I am not sure if the system is equilibrated, since the pressure variations are around 100's of atm, where the average pressure ...
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25 views

Can you do an n-body simulation in terms of energy and momentum?

An N-body simulation typically works directly in terms of the gravitational forces and accelerations. If you can solve the equations exactly, this is fine, but there are many instances where this is ...
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30 views

Cookbook recommendation for finite element semiconductor simulation possibly using Sentaurus

I've started work for my master's thesis using Synopsys Sentaurus for simulation of semiconductors. I'm interested in the device simulation, that is the physics, not the process simulations. The ...
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42 views

How can I estimate the number of X-Ray photons generated from a x ray tube?

I have this problem. I have an x ray tube of which I know the specific (kV, mA, anode material) and I have to estimate the number of X ray photons hitting the sensor after passing through air and ...
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24 views

Center of Lorentz Field

I am currently trying to write a particle physics library and I have implemented gravitational, spring, and Lorentz interactions between particles. These implementations can be seen here if desired. ...
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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-...
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131 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 ...
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36 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 ...
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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/...
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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 $$ \...
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1answer
113 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 ...
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17 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 ...
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96 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, ...
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76 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 ...
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1answer
54 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 ...
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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 ...
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26 views

Can we use Variational Monte Carlo for degenerate cases?

Consider Simple Example of Bose-Hubbard model $$H=-J\sum\limits_{<i,j>}b_i^{\dagger}b_j+h.c.+\frac{U}{2}\sum\limits_{i}n_i(n_i-1) . \tag{1}$$ We can solve this Hamiltonian by Variational ...
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45 views

How to simulate “inside-out” geometries of a structure?

How can I simulate the structural deformation of a physical material to find all possible "stable" inside out forms? For example, some dome shaped rubber caps can be pushed inside out, like the ...
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1answer
71 views

How do I evaluate the angular momentum of the wave function?

I'm working with Bose-Einstein condensates and running a 2D single component Gross-Pitaevskii equation solver for the simulations in MATLAB. The way it works is that it numerically solves the GP ...
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1answer
493 views

How to calculate impulse force on collision?

I've made a program which is supposed to simulate free fall of a ball on a ground. For collision with the ground I relied on calculating the impulse force with the answer in this Phys.SE question ...
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68 views

How to properly implement Huygen's integral?

I'm really confused by what's happening ... I'm trying to propagate a beam some distance and compare initial and final intensities. Lets say the initial electric field is just cos(200x). I then used ...
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70 views

Projectile motion with wind

I am trying to simulate a projectile motion with wind and gravity. (I'm a programmer so excuse my knowledge on the subject) I want to know launch rotation of a person in 3d to throw a ball forward ...
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75 views

Acoustic sound box simulator

I'm looking for a simulator (2 or 3 dimensional + time) of an acoustic box. I'm trying to see where the high/low pressure areas would be depending on where I tap the box on the outside. PS. Not sure ...
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41 views

What discrete form of the wave equation do you need to use to make a wave simulation?

I'm working my way through these blog posts about the wave equation. All has made sense up until now. The wave equation is $$ \frac{\partial^2h}{\partial t^2} = c^2 \frac{\partial^2h}{\partial x^2} $...
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66 views

Explicit Ewald equations for dipole-dipole interaction in a simulation

I'm starting to work with spin ice simulations and I found that it is usual to use the Ewald method for the long-range interactions computation (dipole-dipole in this case). Although I've been reading ...
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77 views

Computer simulation/visualization of a ray of light passing near a massive object

I'd like to write a computer program that simulates and visualizes the trajectory of a ray of light as it passes near a massive object (e.g., neutron star). In other words, I'd like to model light ...
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48 views

What are the limitations of simulating grand unification theories of elementary particles in condensed matter settings?

What are the limitations of simulating grand unification theories of elementary particles in condensed matter settings? I know that condensed matter systems can be constructed to be described by any ...
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50 views

Q: Any standard terminology for “gold standard” Monte Carlo solutions

The "standard" way in our field to compute scattering statistics in wave propagation problems is via a "deterministic" wave prop code operating in a Monte Carlo context where we iterate over many ...
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1answer
29 views

plasma and infinite acceleration

I am trying to set up a simulation of particles (they are not any particular kinds of particles, they are just points that repel each other). All the particles repel each other through the inverse ...
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1answer
100 views

Searl effect generator simulation

This is an scheme of SEG: https://www.youtube.com/watch?v=pUUvhuQtba4 https://www.youtube.com/watch?v=wAMrTxMzrds This mechanism change the electrons around the conversor. Would be really nice to ...