Modeling Definition and 554 Threads

To solve this, I first used the units to work out that a= m* a/m, i.e. t=z/λ. This would allow you to determine the time duration within an interval section by section and then add this to the previous ones to obtain the age of the respective layer. However, this would require a constant...

Hello, I am a student from Ireland in the final year of a BSc in physics and am looking around for a master's to apply for. I would really like a master's degree that has a strong focus/track on modeling and simulation. I was unsure whether it would be better to apply to a more theoretical...

Hi all, I am trying to derive a relation (as function of temperature) for the coefficient of linear thermal expansion (CLTE) strating from a correlation for the density. But I'm getting a huge discrepancy from the experimental data. I'll start telling you some reasoning I did to get a relation...

Hi For a personal project, I am looking for software that models a QCL laser. It can be free or for a small fee. Any help would be appreciated. Thanks. Adrian

Hello I'm reading this research paper about obtaining an accurate DC-link capacitor current equation. I've attached the paper. Im struggling to understand a few things and was hoping someone could help with them. 1) How is the the value marked in the bracket after each V vector describing the...

Hi I am back :). I have been doing some Simulink modeling for a project. I modeled it with a discrete system due to the controller rate. I have noticed that for all the discrete system I have tried, adding a derivative filter not only improves the performance (smaller settling time), but it is...

Hi All, I am trying to model this mechanism for a project. It is a switch that uses a solenoid to break the contact by lifting the aluminium arm. I understand that there is most likely software out there that can do this but i would like to understand how to model this from first principals. I...

I started to study synchronous generator modelling some time ago... Quite a rabbit hole to say the least. So, there are basically two types of models : abc reference frame models aka phase variable models and dq0 reference models. dq0 are primarily used for steady state modelling of generators...

I am currently taking some time off of college (I am a sophomore), and I'm trying to continue coding and experimenting with Calculus-y math as I'll be going into Calculus II and then III when I go back. I am currently trying to develop a 3D baseball pitch visualizer for my own purposes. I am not...

I have the following constrained optimization problem corresponding to the maximum likelihood density estimation: $$ \begin{aligned} &\text{maximize} && L(f) \\ &\text{subject to} && f \in H \\ &&& \int_a^b f(x) \mathop{}\!\mathrm{d} x = 1 \\ &&& f(x) \geq 0...

I use macro definition to model the results can be viewed in vised but vised does not display all the big guy know? Is there something wrong with my modeling?

C 1 1 -19.35 -7 1 -2 2 1 -19.35 -8 3 -4 3 1 -19.35 -5:-6 4 0 5 6 #1 #2 C 1 RCC 0 -10 0 0 -10 10 2 2 RCC 0 -10 0 0 -10 10 5 3 RCC 0 10 0 0 10 10 2 4 RCC 0 10 0 0 10 10 5 5 RPP 2 5 -10 10 0 10 6 RPP -3 0 -15 15 0 10 7 RPP 0 5 -15 -10 0 10 8 RPP 0 5 10 15 0 10 C M1 074184 1

Modeling and simulation, or computational physics/chemistry, is a large and important part of engineering. In nuclear energy, there are applications of finite element methods (and occasionally finite different or finite volume depending on the problem) applied to nuclear plants, nuclear...

Modeling the time evolution of the sun and earth orbiting each other using ##F = \frac{GMm}{r^2}## is straightforward. However, it appears that modeling the time evolution of the same 2 body system using general relativity seems to be a hard/intractable problem? There was in depth discussion by...

Say there is a gas made up of two gas molecules: Molecule A and Molecule B. Molecule A has a mass: ma and mole fraction: na. Molecule B has a mass: mb and mole fraction: nb. The gas is at thermal equilibrium and has a constant temperature throughout itself (T) everywhere. It is placed in a...

The problem gives these data external (cold) air temperature: ##T_c = 20^\circ{\rm C}## internal (hot) air temperature: ##T_h = 80^\circ{\rm C}## lantern volume ##V=0.2 {\rm m^3}## lantern surface ##A=2.0 {\rm m^2}## lantern mass ##m_{\rm L}=30 {\rm g}## external convective heat transfer...

It is often said that one of the drawbacks of the standard model is that it has many free parameters. My question is two-fold: What exactly is a free parameter? My understanding is that the free parameters of a model/theory are the ones that cannot be predicted by the theory and need to be...

I am trying to model numerically the following system: A rigid body mass is rotating freely around an axis (no rotational stiffness/damping) within a range, let's assume plus-minus 3 degrees for now. Case A. The external forces on the mass are low and keep changing which results in the situation...

How can I mathematically model a real system and predict values from that system? I have a real device that produces data that I can graph. The data looks like a sinewave. I want to use an sinewave fit equation to predict some of the measurements because of how long it takes to run a...

how does the partial pressure of oxygen (O2) that is raised to the (1/2) power "magically" combines to give PSO3? , i know that at constant Temperature you can pretty much express pressures between reactants and products using conversion but still you won't be able to factorize because they are...

Hello, I'm trying to solve this problem but I'm confused with some things, is correct that in the system there are two input forces, the torque and u(t)? I assumed that the system has two free levels, which are the z displacement and theta (rotational movement), so the system has a linear...

I am looking at modeling a PV cell and I'm trying to understand the real difference between the single diode and double diode mode. I now realize that I don't fully understand the purpose of the diode in the model in the first place. I've just learned that it was there and went with it. I...

Please see question attached. I am really stuck on this.

I've attached my attempts at the solution and the actual question below. I believe the only issue I am having is I don't know how to get rid of "I" in both my final inductor and capacitor equations as the HW states I shouldn't have anything in term of I. I believe I need to put "I" in terms of...

Summary:: How can I get mathematics modeling for these tree systems? First of all, my mother tongue is not English, so my expression could be ambiguous. I want to get mathematics modeling for these three system above, like this form. First one is b -> (b1+b2), right? but I'm not sure...

find the whole idea of modelling real world events involving human beings an interesting intersection of math, science and bull####. The idea of assigning a probabilty to a complex event like an election seems like scientism at its worst. If someone who has studies past elections says ‘my...

I am a junior engineer tasked with modeling the dynamics of a small research UAV after landing. The UAV has 3 tires, 1 on the nose landing gear and 2 on the rear landing gear. The rear tires are equipped with disc brake calipers. My coworker has explained that the simplified model (MODEL 1...

I'm writing a physics simulation to mimic the old equipotential mapping experiment like this one. I can't find much information on how the voltage across this semi-conducting sheet relates to the E-field. Before I start heading down the path sheet resistance and the resistivity of thin-film...

I am trying to model stress in simple objects such as a disk, a cube, a rectangular prism or a solid ball under their own weight or additional point mass weight on top to demonstrate such material response to students. I understand the usual process is to set up Mesh, boundary condition, and...

Hii Friends. I was trying to model an Induction motor in ANSYS Maxwell 2D. The final output of Transient torque (negative torque) looks like shown below. The input passed is a sine wave current with 120 deg phase shift. Any Suggestion will be highly appreciated

At a total loss here

Honestly not sure how to go about this. Again this is one equation of 4 that I have. I considered using Laplace transforms but taking the Laplace transform of a step function whose argument is one of the variables being solved for doesn't seem possible. Also, if there is an alternative way to...

Basically, I want to know if my assumptions and workings are correct. This is how I see this situation. First, I'm viewing this body as a series of disconnected points, like I have in this animation I made, modeling purely rolling motion. Modeling the body like that worked in that case, and...

Fgravity = m*g Ffriction = k*A*v^2 Ftotal = Fgravity - Ffriction a = Ftotal/m v = v+a*dt if t<7 then Fgravity>Ffriction if 7<t<67 then v =55,88 (meters per second) if t>67 then A = 45 (square meter) if t>67 then Fgravity<Ffriction the t defines the seconds the first 7 seconds are the free fall...

Hey Physics Forum I am currently doing my bachelor project in geophysics, with focus on the evolution of glaciers in Greenland. My project consists partly of programming, because I want to get better at it. I have, however, hit a wall. I can't seem to figure out what is wrong with my code and I...

So far, I have implemented the code below, using Java Priority Queues and Maps. I tried to identify each customer by the time they came in (ranging from 360 and onwards) and their grades. However, this is my first time using priority queues and maps, and I am not very sure if I'm doing things...

From solving the characteristic equations, I got that ##\lambda = 0.5 \pm 1.5i##. Since using either value yields the same answer, let ##\lambda = 0.5 - 1.5i##. Then from solving the system for the eigenvector, I get that the eigenvector is ##{i}\choose{1.5}##. Hence the complex solution is...

hello, I have dynamically modeled a drum boiler, but when i am solving the equation i am getting an negative rate of change of enthalpythe reason i find is the enthalpy of the steam is very higher than the enthalpy of water. can someone please verify the model and help me with this...

import matplotlib.pyplot as plt import numpy as np #constants and conditions initial_velocity = 49.1744 #m/s, book has 110mph velocity_angle = 35 * np.pi / 180 #coverted to radians because numpy only likes radians gravity = 9.8 #m/s^2 dt=0.1 windspeed = 4.4704 #m/s book has 10mph #calculating...

Hello my dear physicists, I'm trying to model the varied generated (needed)Torque to rotate a washing machine Drum during a Washing Process so i assumed that the Model has as Input the target vilocity and as an Output the new needed torque to rotate the Drum(to be as a input for the motor...

I am trying to model an evaporator which evaporates water to steam in Matlab/simulink. Are there any governing equations i need to know and follow when modelling the evaporator mathematically? Please let me know.

Input parameter $$I_{pv}= 8.2 A$$ $$I_{o=}9.8 e -8 A$$ $$R_s=0.221 \Omega$$ $$R_p=415.405 \Omega$$ $$a=1.3$$ $$V_t=21177.82 V$$ source (Villalva, Marcelo G. 2009. Comprehensive Approach to Modeling and Simulation of Photovoltaic Arrays. IEEE Transaction On Power Electronics, Vol. 24, No. 5)...

So I'm trying to figure out how to model a ball getting thrown vertically with the starting velocity v_0. So I've come up with a differential equation which I'm pretty sure is correct: Where D is a constant. So far so good. My problem is solving this. This is my attempt: And when i do this...

I am trying to design a compressor in simulink. the mathematical equations has been modeled. but i just need, is there any relation to find the rate of change of volume with respect to time in compressor. Are there any equations or relations to find the rate of change in volume. As its a...

Hello, The first step in 3D printing is the generation of a 3D model using a CAD software. But to be able to print the object, the CAD software is not enough, even if the file is saved in .stl or .obj format, correct? Another software, called the slicer, must then receive the 3D modeling file...

So this is what I have done: ##f'(t)=k*f(t)*(A-f(t))*(1-sin(\frac{pi*x}{12}))## ##\frac{1}{f(t)*(A-f(t))}=k*(1-sin(\frac{pi*x}{12}))## I see that the left can be written as this (using partial fractions): ##1/A(\frac{1}{f(t)}-\frac{1}{A-f(t)})## And then I take the integral on both sides and...

I have yet to decide on values for the mass of the fixed object, M, the mass of the moving celestial body, m, the initial velocity, v, and the distance between the two objects, r. I will most definitely decide on a larger mass M because I would like the celestial body to spiral in towards the...

Hello everyone, i am Ali a PhD scholar i need some help regarding MCNP, i wand to model a pwr core with spacer grid but i don't know how to model spacer grid can anyone help? Regards

Consider a 3-body Newtonian system with equal masses such that velocity change at a given time epoch for a single body is given by: I am interpreting that if also change per epoch such that say which means as a component. So body state information propagates in a way that one could...