Modelling Definition and 288 Threads

Hello! I'm a student in my 3rd year in physics, and due to low demand for physicits in my country. I'm planning to switch for something else. Right now, I have the opportunity to join a bachelor in Statistical Modelling and Computer Science. I love both majors, and I like how the second one...

I'm making some theoretical modelling for a system, which is effectively 1d in the sense that it is much longer the wide. This means (like in model for quantized conductance) that the energy bands are parabolas with a spacing equal to the energy difference between the ground state, first excited...

Hello! I would like to ask about any software package, where interaction between a moving particle and a monolayer can be simulated. What i need to get is a spectral angular density distribution in the far-field zone within optical frequency range for a problem when a particle crosses a...

Hi everyone, I want to build a car-model which should be good enough to study under-steer/over-steer and test various safety algorithms like ABS, TCS, ESP. Initially I made a quarter car model, here I could implement simple ABS,TCS. Quarter car model supports only longitudinal dynamics and is...

Homework Statement Hi, When finding the steady-state response to a sinusoidal input, since "s" is a complex number, (a + jw), why do we substitute "s" with only the imaginary part (jw) in the transfer function, G(s) , to get G(jw), rather than substituting the whole complex number to get G(a +...

Hi there! I am currently building a simulation to model the propagation of radio waves in seawater in terms of its propagation loss. I have previously discussed the models I've looked at but have settled on a model which depends primarily on the propagation distance ##r##, the carrier wave...

Before I start, I apologise for the information dump that is to follow. I don't expect all questions to be answered or all models to be addressed; I simply feel it is appropriate to provide the community with my current knowledge and stage of research so you may not have to search for it...

In order for me to be able to run a simulation I need to write an equation which calculates the distance from a point inside a circle of radius 'r' to any point along the circle's circumference using a point a distance 0<=d<=r from its center. The ultimate system to be simulated is a radially...

Homework Statement Sorry to disappoint the math fanatics but no this is not a question that integrates all three topics at once but individual ones. I still need assistance though with the following more so in the reasoning behind them as I feel my logic is flawed...

I have attached an image of a question I am trying to do, I want to find the differential equations that describe the second order system in the image. I know for a spring, potential energy = 1/2.K.x (where k is the spring constant, and x is the distance the spring is stretched). I know that...

Hi, I am recently new to Ansys version 14 APDL. Does anyone can help me in modeling masonry building using APDL. I have read many kind of tutorials but still it is very difficult to understand.I hope that someone can help me and teach me how because this is for my thesis where the due date is...

Hi i am working on a research paper for which i need very good citation for the analytic analysis coupling Electric - Thermal-Structural physics(via Joule Thomson effect & Thermal stress/strain). Please provide any good source of mathematical relations describing the above complete or in part...

Hello. I'm currently taking a physics course that gives me the freedom to take any subject related to semiconductors and do some research on it, presenting it at the end of the semester. I know I want to do something related to programming, but I'm having a hard time finding a theme. Hence me...

So if you were to slide a box-like object down a straight ramp with a single gradient (its literally just an incline no curve). And you attempt to model it accurately would this be correct? Given the DE ma=mg-kv where a=dv/dt, mg=force of gravity, kv= force of friction Anyway my main question...

Homework Statement Homework Equations Model diode in reverse direction as an open, model diode in forward direction as a short. The Attempt at a Solution In part e of the question, does the circuit stay in state 1 after it gets into state one or does it change states?

I’m currently constructing a solar wind outflow model, incrementally relaxing a series of initial assumptions in a stage-by-stage process. I’ve now arrived at the stage where I want to consider magnetism – and the MHD equations. My plan is, in what seems the simplest starting point, to...

Hi, I've been working with equilibrium modelling in bleach plants of kraft mills in order to find areas likely of being subjected to mineral scale deposits. This has been rather successful - and it's been done successfully be many people before me. However, now I am interested in applying...

Hello everyone! 1. Homework Statement I want to model the irradiance on a fluid element while it is flowing, from a fixed(above or below) light source that has an irradiance that shows first order decay with time and from x-naught to x-infinity . here are the assumptions: -Laminar flow at...

Hi! I am to model the motion of a meteor as it travels through the atmosphere, taking into account the loss of mass, which is 0.025 kg upon impact (height = 0). I also have to take into account the air resistance on the meteor, the fact that the air density is a function of height and that the...

Hi! I am to model the motion of a meteor as it travels through the atmosphere, taking into account the loss of mass, which is 0.025 kg upon impact (height = 0). I also have to take into account the air resistance on the meteor, the fact that the air density is a function of height and that the...

Im about to graduate with a physics and math double major, so I'm currently searching for graduate programs that include applied physics, applied math, and engineering. Ultimately I am interested in applying science/math to practical applications in engineering or Earth science. My goal is to...

How do we explains space-time through Riemann Calculus?

Hi guys, I am very interested in modelling and simulation as a part of a bachelor physics course. So I am searching for a physics course, as a part of 1st year bachelor study, where you do very much modelling and simulation. Can you name me some universities or universities of applied sciences...

Hi, I had been communicating with Chestermiller for the past many months and I modeled the exhaust gas flowing through the pipe of a car. Now, I had problems with the temperature sensor used, so this model couldn't be applied very well and its been a difficult time due to that. I have to...

I am trying to use computer modelling to see stress. I want to compare it to my hand calculation, which uses the frusta cone method to find the stiffness of the joint. This way, I can check my calculation in a conceptual way. The model includes a nylon insert nut, a threaded rod, a washer and a...

Hello everyone, I'm new here and new to Matlab. I hope I do place the post in the right place. First of all, thanks for viewing my post. Please bear with my English. I tried my best to explain everything clear. If you have any question about anything I wrote or spot any fault, please tell...

Hello everyone, Assume that you have a flat plate, that is moving up and down in a sinusoidal motion with the following equation: y = yo*sin(2*pi*f*t) where yo is the amplitude of the motion, f is the frequency and t is time. There is another smaller size plate attached to the edge...

Hi all, This is my first post on PF so forgive any rookie errors. I'm a 17 year old British student. I have just finished a month long placement at Newcastle University researching my chosen topic of quantum tunnelling. The placement itself was very disappointing and I had no interaction with...

i'm looking for a curve that would have a shape of a snowdrop (the white spring flower) in 3D space. i have tried some sine and cosine functions but they don't give me the right shape. if anyone knows how solve this problem feel free to comment :) (i have tried f(x,y)= sin (x*x + y*y)/(x*x +...

Hi . I am modeling a sodium steam generator in Octave. I build a set of differential equations and solve them with Octave DAE solver. My model works just fine. Now i would like to start implementing controls but I am quite confused with P conroler output signal and with what it actually...

Please help me continue this problem A market vendor bought a crate of mangoes for 55 peso. when the crate was opened he found that 4 pieces were not fit to be sold. If he sells the rest at 80 cents more than the buying price, he gets a profit of 8 peso for these remaining mangoes. How many...

I am a bit confused between single neuron models and population of neuron models. If we have single neuron models (Integrate and fire model etc) then why we want to develop models for population of neurons? Although single neuron models are ordinary differential equations (easy to analyze) and...

Hi everyone! I am doing a simulation of threaded connection in ANSYS workbench and have some problem. In this 2D model, the initial make-up is modeled by setting an "initial overlap" (shown in figure 1). This is how I did: - The initial contact between pin and box as "frictional" with...

Good Evening , i am post graduate student of Thermal Engineering.I have some experience to COMSOL software(but not expert atleast). So now i am doing a project on Modelling a Micro thermal energy harvestor. The problem goes something like this , there is strip made up of bimetal ( material of...

I'm an udergrad, 2nd year physics. I recently got interested in solar physics - one reason being, that I was offered to cooperate on a project, where I'll be doing some sunspot simulations. I really like mathematics and I kinda like the mathematical modelling curriculum. However the...

Consider the two species competition model given by $$ \frac{da}{dt }= \frac {λ_1 a} {a+K_1} - r_{ab}\cdot ab - da, \ \ \ \ \ \ \ \ \ \ (1)$$ $$\frac{db}{dt }= λ_2 b (1-\frac{b}{K_2}) - r_{ba}\cdot ab , \ \ \ \ \ \ \ t>0,\ \ \ \ \ \ \ \ (2)$$ for two interacting species denoted a=a(t) and...

Hi, I am currently writing my master thesis and am confronted with specifying and verifying my approach in a temporal logic. I will shortly explain the basic scenario, but feel free to ask for details ;-) Basically I'm wondering which temporal logic would be the best to use in my circumstances...

Hello guys, I am a computer science PhD student. But my project somehow requires some knowledge about computational fluid dynamic modelling (both discrete and continuous). nowadays I am abit stucked in an issue. I want to model pressure drop across a filter medium dynamically. i assume i have...

Hi there, I am currently a student at Heriot-Watt University and have been given a project of deriving a nonlinear equation of motion for an a380 wing engine. The engine is to be considered as a lumped mass attached to the cantilever beam and the main fuselage is considered having translational...

Hi all, Consider a simple gear system. I want to learn to model this system and write equation for it that any information/state regarding system can be extracted from. thanks

Hello all! I am curious. Sometimes I would like to do a trade study on a mechanical component; so in the interest of time, I think I would use 2D analysis techniques so that a) I can save time on the front end in the CAD package and b) save time on the analysis side of things. But I want...

Homework Statement Construct a Microsoft Excel® spreadsheet that models an internal combustion engine based on the ideal air-standard Diesel cycle. Given the minimum temperature (##T_1##) and pressure (##P_1##) in the cycle, the engine size (##V_1##), the compression ratio (##r_v##), the...

Hi there, I'm trying to create a computer model which takes into account output power in a car due to acceleration, drag and rolling resistance. The car will be accelerating for a set amount of time and I am able to model the power required for this with respect to time, as well as the power...

Hello! I am on my last year of study for my bachelor degree in Mechatronics. Looking back at my courses I can say that what I want to do with my life is mathematical modelling of systems (Be they technical, financial, whatever). My favorite courses so far were the mathematical ones and the...

I can't seem to model this properly. This isn't an assignment, I'm just curious how this will go, lol. So I have this tank with an incoming feed stream with temperature Ti, and an output stream T. It has a jacket where q would be modified depending on the desired output stream T. So I...

Homework Statement A thunder cloud can be loosely modeled by two point charges -q and q at heights h and d above the Earth's surface with d > h. Model the Earth's surface as a conducting plane at z=0. Sketch the Electric field lines (on a plane perpendicular to the earth). Indicate the...

Hi all, I´m a researcher in computational biology thinking on topics quite far from my field. I want to model long thin-walled tubes of dimensions like those treated here, for example: ≈2 m long, radius ≈50mm and thickness ≈1mm. The tubes I´m interested in should be made of...

I am building a mathematical model of a piston engine which calculates the pressure and temperature of the cylinder gas every 1° of crank angle. I'm having some difficulty with the heat transfer to and from the cylinder wall (to when the Tg > Tw and from when Tg < Tw). I found the heat...

I'll be starting a degree course in applied maths and physics next month (though I might change to the theoretical physics pathway next year). I was reading about my course online, and apparently I'll have to choose between two sets of two modules (on top of the 4 compulsory modules). One set...

Galactic Modelling - Bulge formation The bulges at the centres of galaxies often host supermassive black holes (SMBHs), with masses as large as 10^9 M sun. The masses of SMBHs correlate with properties of bulges. Therefore it is important to understand how bulges form in order to understand...