What is Mechanical Engineering?

SR-71 Blackbird

The SR-71 Blackbird, shown in the photograph at the right, is the world's fastest airplane. Its design and manufacture include virtually every area of mechanical engineering.


Engineers in general are the people who make science useful. We put the theories and findings of all of the branches of science to work in ways that benefit people, and we hope benefit the world. Virtually everything you buy or use has had an engineer involved in its production somewhere along the line. Even the food you buy has benefited from the work of engineers who developed tractors, trains, refrigeration cars and, in the case of agricultural engineers, better ways to grow crops. Most of the products you buy were designed and developed directly by engineers.

The scientist explores what is, the engineer creates what has not been.
- Theodore Von Karman

Mechanical engineers design and develop everything you think of as a machine, from the SR-71 Blackbird shown above to toasters and power tools. We design everything that is mechanical such as wheels and axles, airplane bodies, pumps, computer hard drives, bicycles and heart-lung machines. Mechanical engineers are concerned with the production, transmission and use of power. We design and develop systems which produce power such as steam and gas turbines, car engines, nuclear reactors, jet engines and rocket motors. We design and develop the devices that consume power in order to accomplish a useful result, such as refrigeration and air conditioning equipment, elevators and loud-speakers. In addition all of these products must not only be designed, they must also be built. Mechanical engineers design the tools and processes necessary to make all man-made products: robots to assemble cars, methods to melt and shape metals and plastics, tools to assemble circuit boards etc ...

Mechanical engineering is an extremely broad field. Projects being undertaken by mechanical engineers range from medical issues such as the freezing of living tissue and development of an artificial liver, to understanding the currents and waves in the oceans.

Areas of Mechanical Engineering

Mechanical engineering has many fields within it. Using the SR-71 Blackbird as a reference we can quickly identify many problems that need to be studied in order to create an airplane and the fields of mechanical engineering that relate to those problems. The first question is obviously whether it will fly. The field of fluid mechanics includes the study of air flow. In the case of a plane it is the air flow over the wing that determines whether the plane will fly. A study of the air flow will determine the general shape of the wing and aircraft body which will lead to an aircraft design. The wings and body of the aircraft must be strong enough so that they don't collapse or break in flight, but they ought to be as light as possible so that the plane will be able to get off the ground easily and will be as fuel efficient as possible. The design of the body involves the fields of materials science and solid mechanics.

The design of jet engines involves all of the fields of mechanical engineering, but two fields particularly important to engine design are thermodynamics and heat transfer. These two fields are concerned, respectively, with the ability of the engine to produce power to move the airplane, and with the actual combustion or burning of the fuel.

Finally the airplane must have controls so that the pilot can maneuver the airplane.

After all of these systems are designed the airplane must be built. The field of manufacturing deals with how to make all of the parts and how to assemble them.

In a modern manufacturing plant robots would be used to make and assemble the parts of the airplane.

Mechanical Engineers would be responsible for all of these tasks in airplane design and manufacture.

List of Mechanical Engineering Fields