Modeling Definition and 554 Threads

I feel like this is a dumb question, but here goes: I'm trying to model a pendulum with damping. The pendulum is connected to a rubber band (unstretched when the pendulum is vertical) on the right side, and the rubber band is fixed at the other end. How would I go about modeling a rubber band...

This was the equation that they showed me. I thought P was for pressure, V for Volume, T for Temperature, R for Gas Constant, and n for the number of moles. Was I correct for the initials?

Summary: Do physicists really need to master mathematical modeling? Do physicists really need to master mathematical modeling? As far as I know Mathematical modeling is a separate discipline form Physics?

Anybody have experience with it? Is it really meshless or just hiding a mesh generation?

I am in a process of making a mathematical model of an automobile driveline validation procedure called "Driveline impact". In this test, after the engine in cranked, first gear is selected. While clutch pedal is still pressed, engine rpm is raised unto its max. torque deliverable speed. In this...

I modeled a throttle body in Simulink. How do I model the position of the gas pedal so that if the position of the gas pedal changes the input voltage to the throttle body actuator will change and open the throttle? why should i give on the left side to get position of the gas pedal from the...

Summary: Relation between deformed foil and friction force Good morning everyone, i have a small leaf or steel that is bent from one side by a Pressure of many bars. in front of the leaf there's a rotating disk, separated by the leaf by a small gap. this leaf, as it deforms, wins the gaps and...

The rate at which glucose enters the bloodstream is ##r## units per minute so: ## \frac{dI}{dt} = r ## The rate at which it leaves the body is: ##\frac {dE}{dt} = -k Q(t) ## Then the rate at which the glucose in the body changes is: A) ## Q'(t) = \frac{dI}{dt} + \frac {dE}{dt} = r - k...

I am a beginner to mechanics and am finding it very difficult to visualize/model what happens if I push a box quickly and let go. I know how to model the scenario when the box is continually pushed by a force. We simply use ##F=ma## where ##F## is the force. If the ground is rough, we also use...

Hello everyone, I am wondering how to model ambient air around a thermoelectric module in COMSOL. I am fairly new to the software and am doing undergraduate research revolved around it. Any help or pertinent examples would be appreciated. I can send/post screenshots and or .mph files if it would...

Imagine an half car model with the two suspension and two wheels. There is a torque applied to the rear wheels, that torque create the force between tire/asphalt that pull the car. How that torque react in the main body? I have two hypotesis: 1) It's only internal force that tend to bend the...

Hi All, I'm really struggling with the below question - I'm not sure if I've taken the correct approach to determining the model as there may be an easier way to do this? Any help in much appreciated, please let me know if I have submitted this template correctly as this if my first time...

Dear Everyone, I am having trouble with how to start with one part of the question: "In this exercise, we derived the PDE that models the vibrations of a hanging chain of length $L$. For convenience, the x-axis placed vertically with the positive direction pointing upward, and the fixed end...

Hello new to the forum. I'm a builder by trade and enjoy studying the concepts behind the things I build. My problem is: A typical concrete post and base panel with a wooden fence. Unit mass approximately 350kgs including the foundation concrete around the posts. 2.0m wide x 2.0m above...

Hello everyone, I am new here, and wondering if anyone would have some knowledge on a current problem I have been working on. I am trying to create time- and frequency domain 3D models of an object hanging using a spring from a fixed point within a shell. I am trying to figure out how the...

In this task of mine, I need to develop a tool/software to carry out (dynamic) hydraulic analysis of a central heating network, formed with supply and return pipes so forming a multi-parallel loops in a closed circuit, as can be seen in the below picture. Can anyone suggest me some references...

Homework Statement [/B] Let us assume that neutral atoms or molecules can be modeled as harmonic oscillators in some cases. Then, the equation of the displacement between nucleus and electron cloud can be written as $$\mu\left(\frac{d^x}{dt^2}+\gamma\frac{dx}{dt}+\omega_0^2x\right)=qE.$$ where...

I am a masters student in the UK. For my project I have to monitor the efficiency of zinc sulphide detectors for monitoring alpha particles in liquid solutions. I need to model things like the proximity of the detector to the liquid, the size of the detector and the thickness of the light-tight...

Hi Everyone i'm new member of Physics Forums, my research field is about Switched Reluctance Motors i have question about Optimetrics in Maxwell! my question is: How can Optimize Design Parameters ( like Outer and inner Diameter of Stator and Rotor or Embrace of them) of a Switched Reluctance...

Homework Statement Determine the parameters of the PI controller such that two of the closed-loop poles of the transfer function Gclr(s) correspond to the poles of a second order LTI system with the following specifications: i) overshoot S% = 25%; and ii) settling time ts(5%) = 120 s. Homework...

Some time ago I made a modelling project and obtained a plot. Now, I want to remember what the transfer function was, as I want to try changing the parameters. The graph is the following: How can I obtain the transfer function? Thanks a lot

Hi. I was trying to test a code for the diffusion equation, using the analytical solution for infinite media, with a Dirac delta source term: ##q(\mathbf{r},t)=\delta (\mathbf{r}) \delta (t)##. The code is not giving the analytical solution, and there might be several reasons why this is so...

Hello PF, I am new to the science of turbulence and fluids but recently I have been working with my professor on 2D steady state turbulence and I was looking for a way to model and simulate this scenario: I have a flow affected by a spatially varying magnetic field and having a current pass by...

Homework Statement Hi, So I have a perfectly insulated rectangular plate and I trying to use the 2D heat equation in conjunction with numerical finite diference methods and MATLAB to see how the temperature changes throughout the plate. My issue is with the heat source. I am supposed to decide...

Homework Statement A plane starts its descent from height ##y =h## at ##x = -L## to land at ##(0,0)##. Choose ##a, b, c, d## so its landing path ##y =ax^3 + bx^2 + cx + d## is "smooth". With ##\frac{\mathrm {d}x}{\mathrm {d}t} = V =##constant, find ##\frac{\mathrm {d}y}{\mathrm {d}t}## and...

Looking for existing examples of or guidance on building computer simulations of simple N-bodies in relativist situations. Of particular interest is the simulation of a planet orbiting a star whilst that trivial solar system is caught in a dark flow of relativist velocity; maybe .8 or .9 C. Not...

I'm working on a project at university to calculate the magnetocaloric effect of dysprosium. This will be done using a new technique designed at the university of which its not necessary to go into detail about. In short, the Dy is placed in a solenoid, through which a current runs, the current...

Homework Statement I am trying to model a structure that has moment connections between some beams and columns, and shear connections between the remaining beam and columns in 3D. The software I am using (S-Frame 11) gives me an error when running the analysis for the nodes that I have...

Say I have a function that represents the population growth of a certain country that can be written as ##f\left(x\right)=1.25\left(1.012\right)^t##, where t is in years. I can graph this function and it will look a certain way exponentially. I've looked at a ton of examples, and they're all...

Hi guys, I'm wanting to test materials developed in CAD software for their radiation blocking qualities (EM Spectrum), I would ideally need to use a software where I can set the wavelength and frequency of the emitter and set up a receiver, allowing me to place different materials in the middle...

Hello, I have an problem with mathematical modelling of a special kind of articulated trailer (please have a look at the images: 1st image is the yaw plane and the second is the ZX plane). I have two methods of deriving equations of motion namely Lagrange and Newton-euler to analyse their...

I need to model a system of water flow from a gate whose opening is a function of time the height of the reservoir = H width of the gate = w opening of the gate = f(t) = 0.01t^2 how can i create a differential equation that takes an account of the varying area of the gate?

Consider, I have a dynamic system model for air compressor. Which means I have modeled the system by including its physics. Does this means I also included the transients of the system? What I think is, when i modeled any system with equations, I think that includes the transients. Is it...

mod: approved HexSim Life History Simulation Modeling Platform - free to download. Landscape ecology, anyone? After >10 years of development, the HexSim life history simulator is ready for use by students and researchers.HexSim is a free, versatile, multi-species, life history simulator ideal...

I always had an interest in science. At SUNYA, I took a lot of science, and did modeling for Jay Forrester's Club of Rome Report. My junior thesis was based on that work, and my advisors laughed at it, so I decided that I did not want a degree from SUNYA. My second choice university did not...

In Quantum Optics by Mark Fox, it says that a lossy medium can be modeled by a beam splitter that splits part of the input and sends it to the "loss port", while the unabsorbed energy propagates to the output. This model accounts correctly for the loss, the increased noise at the output etc. Is...

This is only the third thing that I've created in 3D modeling. If you played the PC video game Quake 2 back in 1998, then you might remember this. https://imgur.com/a/dqEqD

Hello, I am running a program that takes relatively long time to read the corpus of some documents, and create the topic model. The code to do this is: from gensim import models, corpora corpus = corpora.BleiCorpus('./data/ap/ap.dat', './data/ap/vocab.txt') #Creating the topic model model =...

Vibrations - Modelling system, equation of motion Hi, In the first question (question 4) in the attached file, how would you go about modelling the system and finding the equation of motion? All those masses are confusing me, I don't even know where to start. I don't know whether the angle...

I am taking a my first water management course and I need your help getting through my first Water Supply Reliability Modeling assignment. It involves a data set that I must manipulate and a problem set. I am not a civil engineer, so I do not know where to start with this. The only hint I have...

I am trying to write code for analytical solution of 1D heat conduction equation in semi-infinite rod. The analytical solution is given by Carslaw and Jaeger 1959 (p305) as $$ h(x,t) = \Delta H .erfc( \frac{x}{2 \sqrt[]{vt} } ) $$ where x is distance, v is diffusivity (material property) and t...

I've previously studied and used the k-epsilon turbulence model within Ansys to model water in a small stirred vessel. I am now interested in CFD models appropriate for modeling flue gas dispersion. I'd like to know: What additional considerations are required for modeling a gas as opposed to...

Suppose a spring with spring constant 6N/m is horizontal and has one end attached to the wall and the other end attached to a 3 kg mass. Suppose the friction/damping constant is 1 N s/m Set up a differential equation that describes this system with x denoting displacement of the mass from...

I'm working on modeling a basic mechanical power system for a video game project. The transfer system consists of meshing gears, belts, and axles/shafts which can have basic clutches that engage/disengage. There are also power producers (hand crank, windmills, water wheels, turbines) and...

Hi all, I have just measured the pressure on a point of a tillage tool and the resulting signals is reported in the following link. In literature, tillage tool are modeled with a constant pressure, but i reality the pressure changes over time and I would like to model the pressure...

Hello, I'm having difficulty finding equation of motion for 3 degree of freedom spring mass system. Homework Statement the positions of the masses at the equilibre are respectively X10, X20, X30 At t = 0s, the mass m1 is drawn to the...

I am thoroughly confused regarding the modeling and graphic depictions of gravitational wave propagation. These waves must propagate in three dimensions, not in the planar rubber sheet example that is often shown or the ripples on a pond example. Even the recently publicized example of the...

Preface There are lots of times in physics when we use approximations of a more accurate or fundamental physics theory because it is easier to work with. For example, in quantum chromodynamics (QCD) lots of calculations are done using the Schwinger-Dyson equations rather than the actual...

Homework Statement Suppose at time zero, the bob was drawn upward four units from the equilibrium position, let C=2, K=2, m=1 lbm, initial speed=2 unit/sec find an expression for body's position. and in the solution it says: y''+6y'+5y=0 my question is: from where does the numbers (6) and (5)...

Homework Statement Can't model a simplfied version of my problem, it's a Steady State Thermal problem. I'm trying to get the superficial temperature of a copper tube and the heat transfer from a flame to the tube(this is a simplified version of the problem). Now my problem started when I...