AEROFOIL AND HYDROFOIL

Aerofoil is an interesting and ingenious shape which helps us to fly in the air-plane.

The shape is more curved on the top and less curved at the bottom. It is fixed at an inclined angle to the air plane wings. The working of the foil can be explained in two ways.

1. Bernoulli's principle
Consider wide width pipe connected to a narrow width nozzle. When the water flow from the pipe to the nozzle, the speed of flow increases;consequently we get forceful jet of water from the nozzle. (eg: water fountains). It happens because of the conservation principle. "Same quantity of water must enter and leave the pipe in the same time". Here the water flow is constrained by narrow nozzle; Hence speed has to increase to maintain conservation principle.

In the case of aerofoil; when the plane runs or flies, the air-flow is constrained by top curvature; Hence the wind speed will increase and consequently air pressure drops over the foil (Bernoulli's principle). Below the foil, the wind flows normally and there is high air pressure compared to the top surface. Hence the airplane is lifted up.

2. Molecular theory
If you run in the rain, the rain will fall slantingly on your front body. The back of your body will remain almost dry. Similarly for a foil, most of air molecules will easily flow underneath it. Only less air molecules will flow over the foil because of the curvature and the angle of inclination. Hence more pressure under the aerofoil than above it.

HYDROFOIL:

Hydrofoil is the same structure; attached to the bottom of the boat and moves in water. When the boat goes fast, water pressure lifts up the hydrofoil and the hull of the boat. (You might have seen it in the boat chasing movie scenes)
Once the hull of the boat is lifted up, it is easy to stir and manure the boat. And also less fuel is consumed.

Note: The wind mill blades look like airplane wings. Their design also based on aerofoil. The blades always directly face the flow of wind. Each blade is one by one lifted by the wind flow. Hence they keep rotating.

-----------------------------------------------------

Comments

THE EARTH, A SUPER ORGANISM

JOIN MY COURSE: "Become a programmer in a day with python" A man called 'love lock' (what a name) proposed a theory called Gaia theory, named after Greek Goddess. It says, "Earth is a self-regulating organism like a human being. The organic life in it interacts with in-organic matter and maintains atmosphere, temperature and environment". Hence the earth is still suitable for the life to thrive. Imagine, in a particular place, there are lot of flowers. Some flowers are white and some are darkly coloured. We know, white reflects light and heat while dark absorbs the same. White flowers can thrive in hot climate. But dark flowers requires cold climate. The absorption and reflection balances and the environment reaches average, warm temperature at which both the flowers can co-exist. This is the essence of "Gaia" theory. On our earth, the oxygen constitute 20% of the atmosphere. The oxygen level is always mai

THE PARABOLA

A jet of water shooting from a hose pipe will follow a parabolic path. What is the so special about parabola. Y= x^2 Draw a graph for the above equation. It will result in a parabola. This parabola is also called unit parabola. Any equation involving square will yield a parabola. Example: Y = 2x^2 +3x+3 (also called quadratic equation) X= 2 and -2, both satisfies the equation 4 = X^2. Parabolic equations always have two solutions. Any motion taking place freely under gravity follows parabolic path. Examples: An object dropped from a moving train, A bomb dropped from flying plane, A ball kicked upwards. If a beam of light rays fall on the parabolic shaped mirror, they will be reflected and brought to focus on a point. This fact is made use of in Dish Antenna, Telescope mirrors, etc. Inverted parabola shape is used in the construction of buildings and bridges. Because the shape is able to bear more weight. A plane

DISORDER IS THE "ORDER OF THE DAY"

Imagine a balloon full of air. The air molecules are moving randomly inside the balloon. Let us pierce the balloon with a pin. The air rushes out. Why should not the air molecules stay inside the balloon safely and ignore the little hole? That is not the way the world works. The molecules always "want to occupy as many states as possible". Hence the air goes out in the open to occupy more volume. The things always goes into disorder (entropy) and the disorder increases with time. The above statement is what we call "second law of thermodynamics". Consider a cup of coffee on the table. Suppose the heat from entire room flows to your cup of coffee, the coffee will boil and the rest of the room will freeze. Freezing means bringing things to order and arrangement. It violates the second law. Hence it will never happen. Hence heat must flow from high temperature to low temperature and not the other way. The air molecules in y

sciencecapsules

Search This Blog