Aerodynamics-Introduction

The term aerodynamics is defined as the science that deals with the flow of air.
There are several basic properties that we use in the study of air.

They are follows

01.Pressure

The normal force per unit area exerted on a surface.

02.Density

The density of a substance is the mass of that substance per unit volume.

03.Temperature

The temperature is a measure of the average Kinetic Energy of a gas.

04.Velocity

The Displacement at a direction per time unit.

05.A streamline

A streamline is the path taken by a molecule of a gas in a steady flow situation.

06.Altitude

Height above sea level

07.Geometric Altitude

The height of the aircraft relative to the local terrain, which could range from sea level to a mountain top.

08.Absolute Altitude

Absolute altitude is the geometric height from the centre of the earth.
I

Aerodynamics - What is an Aerofoil

The speciality of the aerofoil is always the upper camber is longer than the bottom camber.For air molecules to flow from A-B along the upper camber and bottom camber time is equal.As upper camber is longer than the bottom camber the velocity of airflow over the upper camber is higher than the velocity of airflow along the lower camber.According to the Bernoulli's principal outcome pressure of the upper camber is lower than the pressure of the lower camber.Therefore when air is flowing across an aerofoil plane will be lifted.Therefore all aircraft wings are made out of aerofoil shape.

LIFE IN SPACE

We haven't conquered space.Not yet,We have sent some twenty men on camping trips to the moon,and USA and the Soviet Union have sent people to spend restricted lives orbiting the Earth.During the next few weeks for instance,the US space shuttle will take space lab into orbit,showing that ordinary(non astronaut) scientists can live and work in space-for a few days only.

All these are marvelous technical and human achievements.but non of them involves living independently in space.The Russians need food and even oxygen sent up form Earth.And they haven't gone for in to space.The residents of sheffield are farther from London than those of the shuttle or the Soviet's Salyut.It is only in friction ,and in space movies ,that people spend long periods living more or less normally deep in space.