Tuesday 18 September 2018

How Air Bags Work ?

Air Bags:-
An airbag is a type of vehicle safety device and is an occupant restraint system. The airbag module is designed to inflate extremely rapidly then quickly deflate during a collision or impact with a surface or a rapid sudden deceleration. 

The purpose of the airbag is to provide the occupants a soft cushioning and restraint during a crash event to prevent any impact or impact-caused injuries between the flailing occupant and the interior of the vehicle. The airbag provides an energy absorbing surface between the vehicle's occupant and a steering wheel, instrumental panel, A-B-C- structural body frame pillars, headliner and windshield/windscreen.

There are three parts to an airbag that help to accomplish this feature:
>The bag itself is made of a thin, nylon fabric, which is folded into the steering wheel or dashboard or, more recently, the seat or door.
>The sensor is the device that tells the bag to inflate. Inflation happens when there is a collision force equal to running into a brick wall at 10 to 15 miles per hour (16 to 24 km per hour). A mechanical switch is flipped when there is a mass shift that closes an electrical contact, telling the sensors that a crash has occurred. The sensors receive information from an accelerometer built into a microchip.

>The airbag's inflation system reacts sodium azide (NaN3) with potassium nitrate (KNO3) to produce nitrogen gas. Hot blasts of the nitrogen inflate the airbag.

Tuesday 7 August 2018

LAMINAR FLOW Vs.TURBULENT FLOW : DIFFERENCE EXPLAINED !!!

In fluid flows, there are two distinct fluid behaviors experimentally observed. These behaviors were first observed by Sir Osborne Reynolds.We will discuss this in detail in this article.


Laminar Flow

  1. The fluid flow in which the adjacent layers of the fluid do not mix with each other and moves parallel to each other, is called laminar flow.
  2. In the laminar flow, the fluid layer moves in straight line.
  3. The laminar flow always occurs when the fluid flow with low velocity and in small diameter pipes.
  4. The fluid flow having Reynolds number less than 2000 is called laminar flow.
  5. The fluid flow is very orderly i.e. there is no mixing of adjacent layers of the fluid and they move parallel to each other and also with the walls of the pipe.
  6. Shear stress in laminar flow depends only on the viscosity of the fluid and independent of the density.

Turbulent Flow

  1. The fluid flow in which the adjacent layers of the fluid cross each other and do not move parallel to each other, is called turbulent flow.
  2. In turbulent flow the fluid layers do not moves in straight line. They move randomly in zigzag manner.
  3. The turbulent flow occurs when the velocity of the fluid is high and it flows through larger diameter pipes.
  4. The fluid flow having Reynolds number greater than 4000 is called turbulent flow.
  5. The fluid does not flow in definite order. There is a mixing of different layers and they do not move parallel to each other but crosses each other.
  6. The shear stress in turbulent flow depends upon its density.


The difference is summarized in table below.


Hope,you got a clear picture of the difference between the two types of flow.Share this article with your friends.

Monday 6 August 2018

PUMP Vs. COMPRESSOR : DIFFERENCE EXPLAINED !!!


Pump and compressor both are hydraulic machines used to increase the energy of fluid. Both of these devices used in industries and for domestic work. Pump is a device which is used to move the fluid (water, liquid and gases) and increase its elevation. It is mostly used to supply fluid from low elevation to high elevation. A compressor is a device which is a mechanical device just like pump but it increases the potential energy of fluid by compressing it in a closed container.

Difference between pump and compressor

The main difference between pump and compressor is that the pump is used to increase kinetic energy of fluid which further increases the elevation or pressure energy of it.  It moves the fluid from one place to another. But the compressor is mostly used to increase the potential energy (pressure energy) of fluid by pressuring it into a container. It is used to compress the fluid which increases its density and pressure. There are many other differences which are described below.

Difference between pump and compressor: