## The Melting Snow Castle – a diffusion model application

This is an application to the previously derived 2D diffusion (heat transfer) model. The snow melting process is very similar to diffusion or heat transfer. Just open the model and hit “Start-Pause” to see for yourself. It is a 2003 model or earlier. I wasn’t able to run it in 2007 with animation but I’ve got some friends who managed to runContinue Reading

## Building a Dynamic Two Dimensional Heat Transfer Model – part #2

This is the second half of the tutorial which shows how to build a basic animated 2D heat transfer model in Excel. [sociallocker][/sociallocker] Building a Dynamic Two Dimensional Heat Transfer Model – part #2 by George Lungu – This is the second half of a tutorial which shows how to build a basic dynamic heat conduction model of a squareContinue Reading

## Building a Dynamic Two Dimensional Heat Transfer Model – part #1

Here is the first part of a tutorial which shows how to build a two dimensional heat transfer model in Excel. The presentation shows how to partition a square plate in elementary elements on which the simplest form of the heat storage and heat transfer equations can be applied. The numerical form of the final temperature formula is derived . BuildingContinue Reading

## A Basic 2D Animated Heat Transfer Model (a diffusion model too)

Here is a basic 2D heat transfer model. The first  five worksheets model square plates of 30 x 30 elements. The last worksheet is the model of a 50 x 50 plate. You can modify the initial temperature by hand within the range C21:AF240. It is also a diffusion model. It uses the storage and transport equations derived in the previous tutorials.Continue Reading

## Animated Heat Transfer Modeling for the Average Joe – part #4

This is the last tutorial of the series and it shows how to implement the previously derived formulas into a spreadsheet model. The spreadsheet formulas, the macros and charting of the dynamic data is explained. [sociallocker][/sociallocker] Animated heat transfer modeling for the average Joe – part #4 by George Lungu – This is the last section of the beginner seriesContinue Reading

## Animated Heat Transfer Modeling for the Average Joe – part #3

This section shows how to model heat transfer in a linear bar by dividing it in elementary sections in which the basic linear equations introduced in the previous tutorials can be used. Animated heat transfer modeling for the average Joe – part #3 by George Lungu – This is a new section of the beginner series of tutorials in heatContinue Reading

## Animated Heat Transfer Modeling for the Average Joe – part #2

This is a continuation of the first part of the beginner series of tutorials in heat transfer modeling. The first part introduced the reader to the concept of heat capacity (being analogous to the electrical capacity).  This section continues with the concept of heat conductance which is analogous to the electrical conductance.  Ohm’s law applies. Toward the end, the principleContinue Reading

## Animated Heat Transfer Modeling for the Average Joe – part #1

This the first tutorial on modeling heat transfer at a very introductory level. If you follow this series and spend your own effort in developing your own models you will be able to model heat transfer in very complex shapes (1D, 2D, 3D) in a short time and with the basic understanding of a 12 year old school boy. Animated heat transfer modelingContinue Reading

## A One-Dimensional Dynamic Heat Transfer Model – a diffusion model

Hi guys, Here is a 1D dynamic model I built today simulating heat transfer in a 21-segment bar. Just click on the orange “Demo” button for a quick demo. Hitting “Reset” sets the 21 segments of the bar to the initial conditions which is a fully customizable initial temperature map. Clicking “Start/Pause” starts the simulation and you can watch the bar temperature profileContinue Reading

## How to Model a Phase-Locked Loop (PLL) in Excel – part#4

This last section of introductory PLL modeling shows how to upgrade the model with  adjustable scale charts for three voltage signals within the loop. The model also shows how to create a Lissajous based phase display. [sociallocker][/sociallocker] How to Model a Phase-Locked Loop (PLL) in Excel – part #4 -This is the continuation of part #2 of the PLL tutorial. The previousContinue Reading

## How to Model a Phase-Locked Loop (PLL) in Excel – part#3

This is a continuation of the PLL series of tutorials and it takes the recursive numerical formulas derived in the previous section, implementing a dynamic spreadsheet  model with help from a copy-paste loop type of macro. This macro emulates the behavior of the phase locked loop model in time. At this point, the model is functional. Charting options for the waveformsContinue Reading

## How to Model a Frequency Modulated (FM) Signal – an insight

Both frequency and phase modulation are important not only in electronics but also in science and physics in general. It seems like a trivial chore but when I first tried to model such a signal some time back I hit a hard wall. Our minds easily understand kinematics concepts such as coordinate, speed, acceleration and the relations between them inContinue Reading

## How to Model a Phase-Locked Loop (PLL) in Excel – part#2

This is a continuation of the PLL series of tutorials and it starts by implementing and testing the low pass filter created in the previous section. After that, the block diagram is updated and the presentation begins to show how to build the PLL model in a worksheet using the existing LPF formulas. [sociallocker][/sociallocker] How to Model a Phase-Locked Loop (PLL) inContinue Reading

## How to Model a Phase-Locked Loop (PLL) in Excel – part#1

A Phase-Locked Loop is a type of electronic circuit. It generates an oscillation with the same frequency as a reference oscillation and a relatively constant phase difference  with respect to the same reference. The applications spectrum of such a circuit are extremely wide. Signal modulation, demodulation, detection and filtering, frequency conversion and synthesis are just a fraction of what this circuit can do.Continue Reading

## Casual Introduction to Numerical Methods – spring-mass-damper system model – part#5

In this tutorial, most of the calculations for the numerical simulation a SMD (spring-mas-damper) system will be consolidated into a single formula, the coordinate formula. In this case, in order to calculate the coordinate at the end of a any time step, we will need just the coordinates from the previous two time steps and of course the input parameters (constants). TheseContinue Reading

## Casual Introduction to Numerical Methods – spring-mass-damper system model – part#4

This tutorial explains the principles to generating animation for the spring-mass-damper system analyzed in the previous presentations. [sociallocker][/sociallocker] A casual approach to numerical modeling – part #4 – a Spring-Mass-Damper-System – creating the animation by George Lungu – We are trying to generate animation for the system sketched above knowing the deviation from the equilibrium function of time. This deviation isContinue Reading