How does a 4 stroke engine work ?

4
October 7, 2015
Working of 4 stroke engine with animation



These are the most basic engines used in cars & bikes i.e Four stroke cycle petrol engine OR 4 stroke engine(often called). It is very easy to understand until & unless you wanna do all the thermodynamic calculations & all that stuff ! more “How does a 4 stroke engine work ?”

NASA’s next Mars rover mission – 2020

5
October 1, 2015

After an overwhelming success of Mars rover mission 2012, NASA’s next nuclear powered Mars rover is planned to launch in 2020. Scientists say that – it is gonna be way more smarter & efficient than Curiosity, which is currently exploring the red planet.

Curiosity rover
I mean seriously, this thing is the LORD of robots… just look at it & it’s complexities ! (source:- reddit.com)

Curiosity had an awesome design, heck lot of instruments, also its launch & entry into atmosphere of Mars & its landing – all went perfect as planned.

The rover 2020 mission is planned to explore a selected site which is geologically diverse & gives signs of having a past life.




This rover will collect samples of soil & rock and drop them at a selected point. Later those samples will be scooped up another mission to deliver the specimens collected back to Earth.
The development of this mission is a combination of the “old” and the “new,” said Gentry Lee, chief engineer for Solar System Exploration at NASA’s Jet Propulsion Laboratory (JPL) in California.
Mission engineers said that the rover is going to get a new refined design.

Curiosity has been battling wear & tear on its wheels.

Wheels of Curiosity
Damage caused to the wheels of Curiosity ! (source:- mars.nasa.gov)

The 2020 rover wheels are going to become more heavy along with the rover’s body becoming a little longer. That may change the rover’s mobility system.

We are really looking at ways to make this largely heritage, built-to-print rover drive faster and do more science on the surface of Mars

said Jennifer Trosper, JPL’s mission manager on Mars 2020.

The future rover would have machines which will increase the speed of it even on rough terrains, Trosper said.

NASA-Mars-2020-Rover-instrument-selection-PIA18405
Instruments selected for rover 2020 mission which are also assembled on Curiosity. (source:- mars.nasa.gov)




The mechanical design & additional instruments would make mission efficiency jump from Curiosity’s roughly 55% to 80% !!
Eagerly waiting for _______ !

The Mars Space Laboratory mission rover names –
1st was SOJOURNER;
2nd was OPPORTUNITY & it’s twin SPIRIT;
3rd was CURIOSITY;
all giving a positive inspirational, motivational feeling !

What do you think would be 2020 rover’s name ? Share with us in the comment section below…

source:- economictimes.indiatimes.com

Why are brake lights red ?

5
September 23, 2015

Why only red ? Why not blue, orange, purple, pink or any other colour ?
In case, if you think that red was the favorite colour of the one who had this idea (humour me) then you’re… WRONG !
Seriously, when I came to know about it, I realised that – Yes, everything has a reason ! & the brake lights having red colour has a reason too ! more “Why are brake lights red ?”

How do elevators or lifts work ?

0
September 13, 2015

Seriously, what would have happen if there were no elevators & if people were to walk up &  down a 50 or 100 storey building everyday in cities like NY ! I can’t even imagine the fatigue.

Well, keeping our thought aside, let us see how do elevators work ? more “How do elevators or lifts work ?”

what happens when an aircraft travels more than the speed of sound ?

1
September 10, 2015

Does everything remain normal ? I guess NO.
Fighter jets are specially designed for that – powerful weapons, missiles & high speed. So here we will talk about what happens when an aircraft travels more than the speed of sound or breaks the sound barrier !

Mach number :-
In fluid dynamics, the Mach number(M) is a dimensionless quantity representing the ratio of flow velocity past a boundary to the local speed of sound. If an object travels at speed of sound, it will be called as Mach 1; likewise if the object is travelling at the speed double of sound, it will be called as Mach 2 & so on. The speed represented by Mach number is not constant as the speed of sound depends upon the temperature & the altitude at which aircraft is flying. The Mach number is named after Austrian physicist and philosopher Ernst Mach, a designation proposed by aeronautical engineer Jakob Ackeret.

Here are some things which we are not able to see, observe or experience everyday.

Shock wave :-
The name – it’s cool. We are gonna come across one more cool word later in this post. A shock wave is a type of propagating disturbance. When a wave moves faster than speed of sound, it is called a shock wave. Like other ordinary waves, it carries energy(immense) & can travel through any medium – solid, liquid, gas & plasma. It is characterized by an abrupt, nearly discontinuous change in pressure, temperature and density of the medium. Shock waves arise at explosions, detonation, supersonic movements of bodies, powerful electric discharges etc. This shock wave is sometimes the “father of destruction”. The greatest example is the atom bomb dropped on Hiroshima & Nagasaki. The shock wave had so much energy that the area within couple of miles were instantly vaporised.

Watch the shock wave coming towards the camera after dropping a bomb !

Vapor cone :-
A vapor cone, also known as shock collar or shock egg, is a visible cloud of condensed water. It is typically observed around an aircraft when it is flying at transonic speed(Mach 0.8 – Mach 1). When the pressure drops around a object so does the temperature. In case of aircrafts, the cloud is caused by supersonic expansion fans decreasing the air pressure, density and temperature below the dew point. As the temperature drops below dew point, a cloud is formed.

Vapor-Cone-Flyby
An aircraft creating vapor cone. (source:- maniacworld.com)

Sonic Boom :-
This is the word I was going to talk about. A sonic boom is a sound associated with the shock wave created by an object travelling through air faster than speed of sound. They create enormous amounts of sound energy, much like explosion.
When an aircraft passes through air, it creates a series of pressure waves just like the waves created by the boat. As the speed of aircraft increases these waves are forced to compress. As they are not able to get out of the way of each other, they merge in a single shock wave & thus the sound – boooommmm…

Here is a video containing footages of fighter jets breaking the sound barrier. Also watch the shock waves created by the Atlas rocket at the end of the video which was launched into ideal conditions for showing off shock waves (watch carefully & feel the power of sonic booms !)

holy crap ! somebody just give me a fighter jet 🙁 !!!

 

source :- wikipedia.org

Amazing Archimedean screw !

6
September 6, 2015



The name itself gives us an idea that it is invented by Archimedes.
Now this man – Archimedes, was an Ancient Greek mathematician, engineer, inventor, physicist, & an astronomer(such a smartass). We are living in 21st century & still we are not able to think stuff like this on our own & this man did it in the 3rd century BC !!!!!




We already discussed one of his works – buoyancy & we saw how do ships float ?
So the Archimedean screw OR screw pump is just a simple machine consisting a cylinder & a helical surface on the inside part of cylinder. Basically, it was designed to work like a pump & it worked without any of our presently available motors which we use to run todays pumps. The screw was used mostly for draining water out of mines or other areas of low lying water.

Archimedes-screw_one-screw-threads_with-ball_3D-view_animated_small
Animation of the Archimedean screw. Let us assume that the ball is a water molecule.

 

Construction :-
The screw pump consists of a screw or a helical structure inside a hollow pipe. The screw is turned through a handle which is outside the cylinder. As the shaft turns, the bottom end scoops up a volume of water. The water then gets pushed out up by the rotating helicoid until it pours out from the top of the tube & done just so simple.

Applications OR Uses :-
Why it was made ? – the first purpose was to transfer the water from low lying region to other parts of
the city. Along with transferring water to irrigation ditches, the device was also used for draining land that was underneath the sea in the Netherlands and other places in the creation of polders.

A screw conveyor :-
It is an Archimedean screw contained in a tube & turned by a motor so as to deliver material from one end to other end. It is particularly used for transporting granular materials such as plastic granules used in injection molding and cereal grains.

Conveyer Screw
Conveyor Screw (source :- ibis-int.co.uk)

 Screw turbine :-
If water is poured into the top of Archimedes’s screw, it forces the screw to rotate. The rotating shaft can then be used to drive an electric generator.

Worm gear :-

Worm_Gear

This is actually not an application of the Archimedean screw but yea it might be an inspiration to the one who designed & invented the worm-gear mechanism.It is awesome & I really love it. Remove the outer cylinder of the Archimedes’s screw, mesh a gear of proper tooth thickness with the screw & we are done. Here the screw thing is called worm. Now the reason I love it is because the worm will definitely drive the gear but the gear may or may not drive the worm depending on the design of worm.




(It’s like if you close your door/gate of your house with help of worm gear mechanism, only you would be able to open & close it from inside because only you would be able to rotate the worm. Don’t ever worry about burglars unless & until the gate/door is big enough & not made of wood ! 😛 )

All hail great polymath – ARCHIMEDES !

 

source & animations source :- wikipedia.org

Why does a spinning ball follows a curve path during flight ?

1
September 3, 2015

You must have noticed this while watching a football match that a spinning ball follows a curve path during flight ! So why does this happen ? Lets find out… more “Why does a spinning ball follows a curve path during flight ?”