Simulation Definition and 899 Threads

  1. K

    Modeling, Simulation and Engineering Design.

    Hi guys. I just want to know how Modeling (Mathematical modeling), simulation and Engineering Design are related. Your views are welcome. Any references and links would be appreciated. I just want to know more about the Design Process and how different processes and techniques are used for...
  2. S

    Is Our Reality a Simulation? Exploring the Simulated Reality Hypothesis

    I've been reading book called 'The Big Questions: Physics' by Michael Brooks during my trip to Warsaw. It's an enjoyable collection of essays despite the fact that they were perhaps slightly too basic at times for a physics student like me. What grabbed my attention though was the simulated...
  3. A

    How can I fix my MATLAB code for the simulation of a rate equation?

    i have try this rate equation code in MATLAB. but its not working. can anyone help me please! mm=0; for I = 0.1e-3:0.1e-3:4.5e-3; m=mm+1; q=1.6e-19; alpha=2; Tn=3e-9; Tp=1e-12; G0=0.6; N0 = 1e24; Gamma=.2; epsilon=1e1; Va=3.7e-14; tini=0; tfin=4e-9; dt=1e-12; N(1)=0; S(1)=0...
  4. C

    Kinematics and rigid body simulation

    Hello, I have a question regarding how I'm simulating motion using the common time integrating approach to simulating rigid bodies. I have net forces and solve for position from those: acceleration = force / mass velocity = initial velocity + acceleration * time position = initial position...
  5. E

    LTSpice IV simulation speed adjustments

    Hi everybody. how r u. i'm using linear technology's LTSpice IV to simulate my dc/dc switching power supplies. for that I'm using the chips from the same company. the problem is that when i simulate the circuit using LTSpice IV the simulation speed that it shows is only 25microsecond/s which...
  6. D

    Simulating flow with Direct Simulation Monte Carlo

    Hello everyone! So far I am simulating a Maxwell-Boltzmann distributed gas at 273K in a cube. The walls are thermal but also set to 273K. So the temperature should stay the same throughout the box, which it does. But now I'm trying to get the gas to flow. I'm trying something, but I'm not...
  7. T

    MATLAB Help for Communication simulation in MATLAB.

    Homework Statement I want to simulate OFDM using 16-bit QAM in Simulink. The main problem that I'm facing is regarding generation of digital signals and splitting a digital signal into two or more data streams, as we require in OFDM. Homework Equations The Attempt at a Solution...
  8. H

    How Accurate Are Simulations in Advancing Fusion Research?

    How effective is simulation in fusion research? Many years ago i designed simulators for fission reactors and they were extremely accurate, sometimes approaching 1% accuracy in terms of core behaviour. It seems to me that it should be possible to determine whether ITER can exceed breakeven, for...
  9. K

    Vhdl Temperature simulation help

    Vhdl help! Please help...This is driving me crazy. I am just trying to setup a simple comparing component. The code compiles fine, but the simulation is WAAAAAYY off. could somebody please check this? Thanks --Temprature high or low -- library ieee; use ieee.std_logic_1164.all; entity...
  10. D

    Strange problem with Direct Simulation Monte Carlo

    Hi everyone! I'm running and modifying some code from the Alejandro Garcia book, "Numerical Methods for Physics". I generalized it to three dimensions, but noticed a problem when calculating the average temperature. Then I went back to the original, untouched program, and found that the problem...
  11. K

    Orcad Capture 9.2 LM317 simulation

    hello i'm new to using orcad capture 9.2 so I'm having problems with the simulation. i'm trying to simulate this regulator circuit using transient analysis. then when i clicked run, the green circle appeared. I'm wondering maybe you need to tweak something first on the parameters of the...
  12. F

    Simulation of a double layer capacitance and a warburg impedance with comsol

    Hallo, i'm trying to implement a comsol simulation of a impedance spectroscopy experiment. But unfortunatly I'm an absolut beginner in Comsol and i have many problems with this work. First of all i want to say that I'm using the AC/DC module, more precisely the transient analysis. At the...
  13. H

    Wavefront Simulation using Geometry Optics and Physical Optics

    I am required to simulate the propagation of a the wavefront produced by a laser light (about 633 nm) passing through a system of lens and undergoes a few reflection. What I did at the moment is to do ray tracing, record the optical path length of each ray, then connect every point of the same...
  14. K

    Solving Error Accumulation in Physics Simulation Program

    I'm trying to write a program that will simulate basic gravity on a set of point particles. The problem I'm having is the program accumulates a lot of error very quickly, the particles start gaining speed and soon they're off to weird places. I can also track how the center of mass of the system...
  15. A

    Which Coordinate-Based Model Best Suits Trajectory Simulations?

    Homework Statement I have an assignment in which i need to employ the practice of 'Crowd Sourcing' to get the answers to problem statements. I can have my own answer but i also need the answers collected from various sources. *Kindly help ur answers* The problem statement is ...
  16. E

    Aircraft Simulation for beginners

    Hello everyone For the past 2 years I have slowly and agonisingly tried to make a flight simulator in http://www.blender.org" . I've gotten as far as this (regarding physics): - got the Lift and Drag calculations - got the thrust calculations - got some REALLY basic roll calculations. It is the...
  17. M

    Monte-Carlo simulation for a matrix model

    Hello there, I am writing a Monte-Carlo simulation for a matrix model with a Lagrangian consisting of two parts - Yang-Mills and Chern-Simons type terms. As I am accepting/rejecting new states with probability P=min{1, dL}, where dL is the change of the lagrangian. But then there is...
  18. S

    Simulating Signals for Electrical Engineering Projects

    Hi every body I'm an electerical engeneer with a fair backgraund in telecommunication field.I'm working on a project in which I'm supposed to simulate the whole signal a receiver gets on Earth (from suppose a satellite)with all the specifications like the doppler shift of the transmitted...
  19. R

    MD simulation of crystal oriented along 110, 111 planes

    Dear friends, I am doing a Molecular dynamics simulations of a crystal. For this the initial configuration is FCC (face centered cubic) lattice. My problem is that I have to study the system for different orientations of the crystal i.e. (100) plane, (110) plane and (111) planes. For (100), the...
  20. B

    Exploring System Modeling and Simulation: Applications, Tools, and Education

    Hi all, I am new to Physics Forums. Threads in the forum are excellent. As a Mechanical Engineer, It helps me to discuss about issues encountered in my work and also get to know about issues faced by others in their Engineering practice… To solidify my understanding, I would like to know...
  21. D

    Equation used in simulation software

    Can i know how this simulation softwares(like Pspice, Psim, MATLAB simulink) work ? Which methods they use to solve any circuit with non-linear elements ? How can we solve any circuit numerically ?
  22. N

    Using Google Sketchup for CAD Modeling in FEMM Transformer Simulations?

    hi there, i'm trying to simulate a ETD core http://www.ferroxcube.com/prod/assets/etd29.pdf" transformer using FEMM free software but I'm not getting it...i've done some simulations with pot cores and had no problem with that, using the axissymmetric mode. bue this type of core is not...
  23. W

    Residual stress simulation on Ansys

    Hello, Just wondering how the effect of residual stress on any structure can be shown on ANSYS, any information will be appreciated!
  24. D

    Band structure simulation using Snider program

    Does anyone have any experience using Gregory Snider's 1D Schrodinger/Poisson solver? I'm trying to do some simulations of a quantum well my group is studying, and I'm not sure if I'm doing something wrong or if the code is buggy or if I'm just interpreting the results incorrectly. Here's the...
  25. N

    How Can I Simulate an Accretion Disk Using the Naviar-Strokes Equations?

    I've recently been messing around with the ol' Naviar-Strokes equations, creating a fluid simulator with the help of Mr. Jos Stam. I added vorticity confinement, which made for some really beautiful visual effects. I noticed these appeared similar to an accretion disk. I'd like to model an...
  26. S

    Sources of noise in geostationary satellite attitude determination simulation

    I am doing satellite attitude determination simulation using sun Earth sensors and Gyro modelling .I am using extended kalman filtering for attitude determination. the sequence of operations I am doing are % Simulation data % Spacecraft data % Gyro data % Sensor data. % Control system...
  27. T

    How to Troubleshoot Error 6262 in Laser Simulation Using COMSOL?

    Hey I am trying to create a comsol model to simulate laser forming using comsol. As a starting point I am using the heating with a moving laser tutorial and adapting from there. The first stage is to model the beam modes. I the tutorial the beam is treated as being infitesimally thin and is...
  28. C

    Improving the accuracy of a Java simulation of n-orbital bodies

    Homework Statement So, I'm creating a 2d graphical simulation of orbiting bodies. Right now I'm just working with 2 bodies, one stationary, but I would hope to extend this program to be able to include any number of moving bodies and have them interact accordingly. After combing...
  29. P

    How can torque be converted into speed in a vehicle simulation?

    I have been reading on these forums for a bit learning about vehicles and their physics. I still have a few questions and do want to clarify some things as well. I am trying to simulate a vehicle give some basic info you can find online about any car or vehicle. I know Peak HP and the...
  30. I

    How Can I Create a 3D Magnetic Field Simulation with Ansoft Maxwell?

    Hi guys, this is my first post! I have to simulate in 2D and 3D the magnetic field produced by two permanent magnets arranged vertically and separated by a distance d. For 2D simulation I used the excellent FEMM, I discovered googling on internet, and I must say we are very pleased with the...
  31. U

    Simulating Lime Kiln Combustion - Hi My Name Is Cake

    Hi my name is cake. um not good at enslish. i need lime kiln combustion. ..define>>model>>specie>>transport&reaction>>?
  32. H

    Test Dragster Lift/Drag w/ SolidWorks Flow Simulation

    Is anyone willing to test my dragster in SolidWorks or any kind of cfd software? I been looking all over for some kind of CFD to test my dragster but with no luck and I decided to try SolidWorks, which went well until I realized that I my version doesn't have flow simulation. :cry: Can someone...
  33. S

    R/C Plane Simulation Software - Tips & Advice Wanted

    I hope i posted on the right forum... I've been considering writing a simple(?) R/C flight simulator for quite some time. After reading about aerodynamics i concluded that a simulation software are bound to make great simplifications, and may only model a subset of the actual physics...
  34. F

    Problem for simulation on recollapse model

    Hello, I post another topic because my first main problem about the modelisation of scale factor by solving numerically friedmann equations is resolved. However, It remains one problem, that of the recollapse when integration starts at a early age of the universe. i have reformulated the...
  35. B

    Optimizing Puzzle Solutions through Grid Simulation

    "Evolving grid" simulation? I'm not quite sure what to call this problem, but basically, I am trying to solve a puzzle. It works as follows: There is a 9x9 grid Each square can either be "on" or "off" At the beginning of the puzzle, the 9 squares dead center of the grid are "on", the...
  36. L

    How Do I Update Particle Positions in a Constrained 3D Simulation?

    I am trying to simulate a 3D particle simulation, where there are a 1000 particles of random x,y,z postn varying area between 2 n 4, and mass... There are different forces acting on each particles, Force due to heat, wind, and gravity, we calc acceleration from that, after which change in...
  37. L

    Solving 2D Heat Diffusion Eqn w/ Finite Difference Method

    I have to write a FD expilicit method, for temp dist on 2D plane. I am trying to mod the 1D solver to 2D solver, the code below is a 1D solver. Any possible suggestions how it can be done? I initially, derived u(i,j+1) for 2D for in that derivation i,j corresponds to x,y... where as in 1D...
  38. J

    Implicit integration in large simulation

    hello, I am an animation student at bournemouth university in England, I am writing a material simulator for my final major project ( some preliminary results http://www.youtube.com/user/jorjpimm ). The final idea is to have elastic, plastic and tearing and breaking material characteristics, all...
  39. S

    Quaternion conversion in satellite attitude using sun-earth sensors simulation

    I need to convert quaternion (q) to a form that is suitable to show changing attitude of a Satellite. like new x,y,z vectors of a satellite.I don't know the math of quaternions. I am getting updated state using rung -kutta 4 method where state vector x=[q(1:4) wx wy wz a(1:3) b(1:3)].I can...
  40. S

    Satellite using rung-kutta method for 4DOF or 6DOF simulation

    I am working on sun Earth attitude determination simulation for my satellite in MATLAB using SCT(space craft control toolbox)I have my keplerian elements for my satellite.I have some initial conditions for orbit setting or satellite is known.I need to use RK4 method for quaternion/state...
  41. A

    Expert Help: What do you guys think about this 3D physics simulation ?

    Cannon and proyectile trajectory with data dislayed in real time. Can adjust mass, drag, friction, elasticity, etc. Check it out free at: http://escxsoft.com/FrmPhysica.aspx
  42. E

    Switching power supplies simulation software

    hi does anyone know what kind of simulation software to be used for switching power supplies design. it should be free software available on the net. it may be student version although advanced version will be preferable!
  43. A

    Bus simulation in excel, exponential distribution departure

    Homework Statement The bus service operates between points A and B. The buses depart from the terminal station A with headways that follow the negative exponentioal distributiona with parameter 10 trips per hour. Assume that the characteristics of the system remain the same over time (not...
  44. J

    Compressor Simulation: Calculating Outlet Temperature & Mass Flow Rate

    Hallo friends, I am doing simulation of compressor process. I have used the following equation to calculate compressor outlet Temperature and mass flow rate. mass flow rate (m) : flow from compressor map(m3/h)*compressor pressure/(R*Inlet temp*z) T_outlet :T1+ (head*(kappa-1)/...
  45. A

    What is the level of detail and purpose of this IC engine simulation project?

    Hello this is my first post on the forum, i have very little knowledge in physics and high level mathematics, but for the past few years I've been dabbling with excel on a way to compare and give rough estimates of many facets of engines. At the moment what I am working on is determining the...
  46. L

    Buoyancy in particle-based viscoelastic fluid simulation

    Hello, I'm new here, and have a confession: I'm not a physicist, merely a games programmer. Please be gentle with me, and speak slowly :smile: The stuff I'm looking into seems to be outside the scope of all of the games programming forums I know of, so I thought I'd try here. I'm working...
  47. T

    Air flow caused by fans (game simulation)

    Hi, I'm currently taking a C++ course where we are going to make a project, we are 6 people in our group. We have decided to make a kind of puzzle game, where the goal is to move an object (maybe a ball?) through a room, avoiding obstacles and eventually reaching a goal somewhere in the room...
  48. I

    Expert Help: Does this physics simulation appear realistic to you?

    This is a game called Gran Turismo 5, which is still under development. 10 seconds into the clip, the car drives through some plastic barriers. I find that the barriers are simulated very unrealistically given their reaction to the car, as the force vector modeling appears to be completely...
  49. F

    Gravity Simulation: Consistent Rotation Pattern?

    Hi all. I've been playing around with a simple gravity simulator I wrote in Processing. I have a version that impliments a second degree modified Euler integration scheme on particles in three dimensions. Attached is a screen strip of screen captures showing the first few moments of the...
  50. S

    Become an Expert with Learning Simulation: Physics for RealFlow

    hi :shy:, well ı am a simple student and ı want to ask a question, if you can answer ı will be very glad... it is this: I want (very,very,very much:redface:)to be an expert like this person-http://physbam.stanford.edu/~fedkiw/ and ı am trying to learn this program-(http://www.realflow.com/) but...
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