{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Fluid Kinematics\n", "\n", "\n", "## Learning Outcomes\n", "\n", "This Jupyter Notebook will introduce ideas related to how fluid motion can be described mathematically. These are very important tools that let engineers build systems and machines that involve fluid flow. Examples are vehicles of all kinds, pumps and engines, weather simulations, domestic plumbing systems and medical implants.\n", "\n", "The following concepts will be discussed in detail:\n", "\n", "* Velocity fields\n", "* Eulerian and Lagrangian descriptions of fluid motion.\n", "* Streamlines, pathlines, and streaklines\n", "\n", "Most of you should be familiar with the idea of a vector field already but it's always a good idea to take a fresh look. Concepts such as Eulerian and Lagrangian descriptions might seem abstract at first but they are important ideas in taming the complex nature of fluid flow which allows us to work as engineers. In the next notebook we will look at the Reynolds Transport Theorem, which will allow us to move from the Lagrangian to the Eulerian description. As you will see this will make analysis of many flows much easier.\n", "\n", "You will no doubt have heard the term 'streamlined' before and perhaps have a feeling for what it means. It might be along the lines that a race car is streamlined while a bus or a lorry is not. Here we will describe what streamlines mean mathematically and also introduce the related ideas of pathlines and streaklines and how we can use them to describe fluid flow." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Vector fields" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Lets take a step back from this complexity and deal with some of the basics.\n", "\n", "Take a look at the weather map of Ireland below. Each icon on this map is fixed in space (longitude and latitude) and the pointy end indicates the direction of the wind. The numeric value indicates the speed of the wind. Therefore the icon gives us the local *velocity vector*. A field of these vectors arranged over a space is a vector field.\n", "\n", "\n", "