1. ### Mathematical modeling of a screw compressor

I am trying to design a compressor in simulink. the mathematical equations has been modelled. 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...
2. ### I Justifying a correlation

all the references I can find on the net to justifying a correlation treat it as a matter of judgment, and, quite correctly, that it depends on the application. But it seems to me that one could compare the fit to the data of a horizontal line (i.e. average y) with that of the linear regression...
3. ### A Partial Differential Equation Mathematical Modelling

Salutations, I have been trying to approach a modelling case about organism propagation which reproducing with velocity $$\alpha$$ spreading randomly according these equations: \frac{du(x,t)}{dt}=k\frac{d^2u}{dx^2} +\alpha u(x,t)\\\ \\ u(x,0)=\delta(x)\\\ \lim\limits_{x \to \pm\infty}...
4. ### Dynamic modeling of a system and transients of the system

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

### Coil connection in Ansys

Hello everyone, wondering if you can give some help with ansys Maxwell 3D modelling. I'm working on the design of a new type of transformer and according my drawings and calculations I need to physical connect (not mutually-inducted) three coils in the secondary side of the transformer, they...
6. ### Why does not this Erdos-Renyi C code work?

Homework Statement I need to write an Erdos-Renyi random graph, by using the adjacency matrix (or alternatively list) and calculate the fitness of the graph. Definition: G(n, p) is a random graph with n vertices where each possible edge has probability p of existing. Homework Equations The...
7. ### Modeling epidemics - solving differential equation

I am given a modified SIR model in which the rate of decrease of susceptibles S is proportional to the number of susceptibles and the square-root of the number if infectives, I. If the number R of those who have been removed or recovered increases in proportion to the infectives, we have the...
8. ### I Chernobyl Dose Model & Estimates

Hello all, I've been tasked with developing a model for dose received from the Chernobyl Accident. I'm struggling a little to find dose estimates from which I can extrapolate back to find the initial dose received. Does anyone have any references that they can point me towards? I believe there...
9. ### I Why is DNS more computationally expensive than k-ε?

In the modelling of turbulent flows, DNS is often too computationally expensive. Therefore, we take a 'statistical' approach and use mean flow equations, which require closure on account of the Reynolds stress. One way to do that is through the Eddy Viscosity Hypothesis, and one of the ways of...
10. ### What is a positive sequence model of an induction machine?

I'm trying to understand a 3 phase induction machine model used as a generator in a Doubly Fed Induction Generator (DFIG) arrangement in Simulink. In this model for the induction generator component, they have stated that the model is a "Positive sequence model" of the induction generator...
11. ### Describing elliptic orbit as a parametric function

Hi PF I've beent rying to model the lunar orbit around the sun (cardioide) as a parametric function, but have run into a problem. f(t) = r(t) : x = a cos(ωt) y = b sin(ωt) z = k t The angular frequency ω as well as the distance from to the center varies around the orbit. Is...
12. ### Consequences of Choosing Incorrect Variables in BuckinghamPi

This question arose as I was studying mathematical modeling in fluid mechanics. It was posted to math.stackexchange, but there a was a lack of response, probably due to the applied nature of the problem. One form of the Buckingham Pi Theorem says that for nn variables with kk dimensions, the...
13. ### Use of Bicycle car model?

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...
14. ### Understanding propagation loss: What does this output mean?

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...
15. ### How is radio wave propagation modelled in seawater?

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...
16. ### Engineering Mathematical modelling of Electric-Thermal-Structuralphysics

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...
17. ### Research theme about semiconductors involving programming

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...
18. ### Equilibrium modelling in kraft mills

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...
19. ### Modeling: Light irradiance and spatio-temporal decay

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...
20. ### Schools Graduate school in applied math, physics, or engineering?

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...
21. ### Bachelor physics course with a large amount of modelling / simulation

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...