Mechanical engineering

Gears, engine cycles, and fluid dynamics

What is mechanical engineering?

Mechanical engineering is the branch of engineering concerned with designing, analyzing, and building machines and mechanical systems — anything that involves moving parts, forces, and energy conversion, from engines and turbines to everyday household appliances.

Machines and mechanisms

A machine takes in energy or force and converts it into useful work. Mechanical engineers design the individual mechanisms that make this possible: gears (which transmit rotational motion and can change speed or force), levers, pulleys, and linkages, all built on the fundamental physics principles covered in the Mechanics article.

Energy conversion

A large part of mechanical engineering deals with converting energy from one form to another — burning fuel to produce heat, then converting that heat into mechanical motion (as in a car engine), or converting motion into electricity (as in a generator). These processes rely directly on the thermodynamics covered in the Thermodynamics article.

Manufacturing and materials

Mechanical engineers also need to understand how to actually manufacture the parts they design, and which materials suit a given application. Choosing a material means balancing factors like strength, weight, cost, and how easily it can be shaped or machined into the needed form.

Why mechanical engineering matters

Mechanical engineering underlies the design of vehicles, engines, industrial machinery, HVAC systems, and countless consumer products — nearly anything with moving parts or that converts energy from one form to another has mechanical engineering behind its design.