Welcome to Episode 2 of my series that helps students choose an engineering discipline. The first discipline is the one I studied in school: mechanical engineering! In this video I attempt to help students answer the question: is mechanical engineering right for me?
I start by exploring events where mechanical engineering may originate from and end with where I think mechanical engineering is going. My hopes are that this video will show potential students what mechanical engineering is all about, what mechanical engineering classes are like, and how mechanical engineering has developed and evolved. So... who should study / do mechanical engineering? YOU, if you can appreciate how mechanical engineering started, feel excited by the courses you’ll take in school, and feel hopeful about the future of mechanical engineering.
01 | History Of Mechanical Engineering
Year: ~200 BC.
Location: Syracuse, Sicily.
A well-known engineer by the name of Archimedes is approached by King Hiero II. The king asks Archimedes to design him a ship worthy of a king. The luxury ship would be named, The Syracusia, after their hometown. This ship would come to be known as one of the largest of its time being able to hold at least 1600 tons of cargo and approximately 2000 people. Archimedes was faced with a problem. Big ships have big hulls. At the time, ships with big hulls were at risk of having too much water leak into the ship and you know what that means. Too much water in the ship means the ship sinks! In order to deal with the enormous amount of water that would leak into the ship, Archimedes designed an ingenious device that consisted of a screw that could be turned inside of a pipe. This formed a simplistic pump. With each turn of the screw water would be lifted up the pipe. This is one of the earliest mechanical engineering devices and it became known as the Archimedes Screw.
Year: ~132 AD
Current rulers: Han Dynasty
In ancient China, an earthquake symbolized that the current rulers had done something wrong in order to upset the heavens. A common mistake that the rulers would make was ignoring the needs of the common person. In order to restore balance to the world and help the people effected by the earthquakes, an engineer by the name of Zhang Heng presented an ancient seismometer to the Han government. On the outside of the seismometer were 8 dragons with small balls in their mouths. They were equally spaced out and pointing to 8 different directions. When an earthquake occurred a pendulum inside would swing, releasing a ball which activated a lever for one of the dragons. This caused the ball in the dragons mouth to fall into the mouth of a toad which would indicate the direction of the earthquake. Zhang Heng’s device represents an early mechanical device used to accurately detect the direction of an earthquake and acts as a precursor for modern seismometers.
Jump forward to around 200 AD, but still in China. Imagine that you are a soldier, and you’re out lurking at night. It would be easy to get lost right? How would you find your way back home? In order to solve this dilemma, Ma Jun, an engineer, created a compass-like device known as the “South-Pointing Chariot”. The chariot used a system of differential gears in order to ensure that a doll positioned on top of the chariot was always pointing south. Although the chariot was not always accurate or precise, it could be used for simple navigation.
Year: ~1206 AD in the middle of the Islamic Golden Age which was a time that many Islamic scientists were offering great contributions to the world.
Location: Northern Mesopotamia
An engineer by the name of Al-Jazari was working on his book titled “The Book of Knowledge of Ingenious Mechanical Devices”. He is credited with creating the camshaft and the crankshaft. Both are considered basic building blocks for any mechanical device in the modern world. He used these devices in order to create one of the first known double-action pumps with a suction line. According to Wikipedia, Al-Jazari’s double-action suction pump "could lift 13.6 metres of water, with the help of delivery pipes” which was quite impressive at the time. Al-Jazari used his knowledge of mechanical systems in order to create one of the first water delivery systems that used gears and hydropower. Using this system he was able to supply water to Mosques and hospitals that needed it.
Time: 17th Century
The 17th Century marked a huge moment for engineering. Sir Isaac Newton had created calculus and formulated his 3 laws which are:
1. An objects velocity remains constant unless acted upon by a net force.
2. The net force on an object is the product of its mass and acceleration. This is commonly seen as the formula F= ma
3. "When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body” - Wikipedia
Newton’s discoveries sparked a more numerical and analytical approach to engineering.
Mechanical engineering really became its own discipline in the 19th Century. Mechanical engineers were needed in order to create, power, and run the new machinery that came during the industrial revolution.
02 | Mechanical Engineering In The Present
As you can see, mechanical engineering has consistently involved the creation and analysis of mechanical devices in order to benefit humanity. However, the mechanical engineers of today have a much broader toolset than the engineers of the past. Typical mechanical engineering curriculums consists of:
Namely calculus, linear algebra, and differential equations.
Statics & Dynamics
Statics is the analysis of systems in equilibrium so the acceleration and net force = 0. Dynamics is the analysis of systems in motion, therefore the net force is not equal to 0. Both consist of analyzing solid systems
Solid mechanics is the analysis of how an objects motion and deformation are affected by various factors like force and temperature.
Thermodynamics is the study of heat and temperature as they are related to work and energy.
Heat transfer is pretty much what it sounds like. It’s the study of how thermal energy is transferred between things.
Fluid mechanics is like statics and dynamic but for liquids, gases, and plasmas.
Math, statics & dynamics, and solid mechanics all echo the mechanical engineers of the past. They are the building blocks for many mechanical devices. However, today's mechanical engineers are also using thermodynamics, heat transfer, and fluid mechanics as a part of their tool kit.
03 | The Future Of Mechanical Engineering
The future of mechanical engineering looks very exciting and I believe that there will be a lot of hybridization between mechanical engineering and other disciplines.
The first exciting field is in microelectromechanical systems or MEMS. MEMS are tiny mechanical devices that are combined with electronics. They are typically about the width of a human hair. An example of MEMS technology is the accelerometer in your phone. An accelerometer is the thing that your phone uses when you play games to track tilting and rotational movement.
In the video above, one of the employees from GE discusses how they are using MEMS technology in order to make switches that open and close faster. I find it very interesting how he said the only way to make a switch faster is to make it smaller!
The next exciting field is biomechanics and biomedical engineering. This field of mechanical engineering involves combining biology and engineering in order to do things like build artificial body parts or mechanical medical devices. Some cool examples of mechanical medical devices would be hearing aids and artificial hearts. Traditionally, students who go down this route take biomedical courses in post-secondary. You definitely need some knowledge of biology and the human anatomy in order to go down this route.
The third field is alternative energy. Solar and wind energy are becoming more economically viable each day. As we slowly deplete our remaining stores of fossil fuels, we will see a rise in alternative energy. Mechanical engineers will play a large role in making these technologies more cost effective, safe, and efficient.
Then we have mechatronics which is the combination of mechanical, electrical, and software engineering. Essentially, the three disciplines are combined in order to automate things. Examples of mechatronics are robots and the autofocus on your camera. In order to go down this route, mechanical engineers will need to increase their knowledge of both electrical and software engineering, or work with others who already have this knowledge.
Lastly, there is computational fluid dynamics or CFD. This is an area of study where computers are used to analyze what happens when a fluid is in motion. For example, CFD is used to see how well a spaceship will perform or how well a plane will fly.
These are just a few of the exciting fields emerging in mechanical engineering. So, you’ve seen the history, the coursework, and a bit of the future for mechanical engineering.