From afbacb8dc22087028017e9b34b0bf1c6e22374be Mon Sep 17 00:00:00 2001 From: Susan Allen Date: Sat, 3 Feb 2024 16:05:19 -0800 Subject: [PATCH] Lab 3, UG second worksheet --- .../Worksheet_UG_Lab3_2_2024.ipynb | 157 ++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 worksheets/Worksheets_Lab3/Worksheet_UG_Lab3_2_2024.ipynb diff --git a/worksheets/Worksheets_Lab3/Worksheet_UG_Lab3_2_2024.ipynb b/worksheets/Worksheets_Lab3/Worksheet_UG_Lab3_2_2024.ipynb new file mode 100644 index 0000000..76fefe2 --- /dev/null +++ b/worksheets/Worksheets_Lab3/Worksheet_UG_Lab3_2_2024.ipynb @@ -0,0 +1,157 @@ +{ + "cells": [ + { + "cell_type": "markdown", + "id": "1533bd8e", + "metadata": {}, + "source": [ + "Names: " + ] + }, + { + "cell_type": "code", + "execution_count": 22, + "id": "8be05185", + "metadata": {}, + "outputs": [], + "source": [ + "# your import statements\n" + ] + }, + { + "cell_type": "markdown", + "id": "c17b4ce4", + "metadata": {}, + "source": [ + "Consider a long hallway (length $L$) in an office building. If we assume that any\n", + "cigarette smoke mixes across the width of the hallway and vertically\n", + "through the depth of the hallway much faster than it mixes along the\n", + "hallway, we can write the diffusion of cigarette smoke as an equation\n", + "$$\\frac {\\partial S} {\\partial t}\n", + "= \\frac {\\partial \\kappa \\partial S}{\\partial x^2}$$\n", + "where $S$ is the concentration of smoke, $\\kappa$ is the rate of diffusion of\n", + "smoke, t is the time and x is\n", + "distance along the hallway. At the centre of the hallway is the smoker and here the smoke is 5 su (smoke units). At one end of the hallway (x=0) is an open window, here the smoke is 0. At the other end of the hallway (x=L) is a closed window (no smoke through the closed window)." + ] + }, + { + "cell_type": "markdown", + "id": "9eb3d006", + "metadata": {}, + "source": [ + "**Question 1**\n", + "\n", + "Under what conditions can you move $\\kappa$ outside the derivative? Make that assumption here, and also make the steady state assumption. What is your new differential equation?" + ] + }, + { + "cell_type": "markdown", + "id": "5f110569", + "metadata": {}, + "source": [] + }, + { + "cell_type": "markdown", + "id": "ace733e0", + "metadata": {}, + "source": [ + "**Question 2**\n", + "\n", + "Using a centre-difference scheme, separating your hallway into $N=10$ divisions (so $N+1=11$ grid points) write down linear equations for the 1th to $N/2-1=4$th grid points and the $N/2+1=6$th to $N-1=9$th grid points. Note that the 0th and $N=10$th grid points are boundary points and there is a special condition at the $N/2=5$th grid point." + ] + }, + { + "cell_type": "markdown", + "id": "b0f3282e", + "metadata": {}, + "source": [] + }, + { + "cell_type": "markdown", + "id": "6bcb3435", + "metadata": {}, + "source": [ + "**Question 3**\n", + "\n", + "What type of boundary condition is at $x=0$ (0th grid point)? Write it as linear equation." + ] + }, + { + "cell_type": "markdown", + "id": "1abcc6cf", + "metadata": {}, + "source": [] + }, + { + "cell_type": "markdown", + "id": "305884ee", + "metadata": {}, + "source": [ + "**Question 4**\n", + "\n", + "What type of boundary condition is at $x=L$ (N=10th grid point)? Write it as linear equation." + ] + }, + { + "cell_type": "markdown", + "id": "9f3f791b", + "metadata": {}, + "source": [] + }, + { + "cell_type": "markdown", + "id": "3ffd3078", + "metadata": {}, + "source": [ + "**Question 5**\n", + "\n", + "Consider the condition at the centre of the hallway ($x=L/2$, $N/2=5$th grid point) Write it as linear equation." + ] + }, + { + "cell_type": "markdown", + "id": "648910b3", + "metadata": {}, + "source": [] + }, + { + "cell_type": "markdown", + "id": "68450247", + "metadata": {}, + "source": [ + "**Question 6**\n", + "\n", + "Put all your equations into a matrix equation and solve the matrix equation. Plot the solution." + ] + }, + { + "cell_type": "code", + "execution_count": null, + "id": "577152a7", + "metadata": {}, + "outputs": [], + "source": [] + } + ], + "metadata": { + "kernelspec": { + "display_name": "Python 3 (ipykernel)", + "language": "python", + "name": "python3" + }, + "language_info": { + "codemirror_mode": { + "name": "ipython", + "version": 3 + }, + "file_extension": ".py", + "mimetype": "text/x-python", + "name": "python", + "nbconvert_exporter": "python", + "pygments_lexer": "ipython3", + "version": "3.10.1" + } + }, + "nbformat": 4, + "nbformat_minor": 5 +}