TP: Defining problem regions

Defining problem regions

In attempting to apply the laws of Thermodynamics in such a way as to solve engineering problems, it is critical that we define exactly the region of space to which we are applying those rules.

DEFINITION:

The universe is all of space.

While the laws of thermodynamics could be applied to the universe, it is usually more convenient to break that space up into:

DEFINITION:

The system is the region of space that is of interest in the problem.

DEFINITION:

The surroundings is all of the space which is not contained within the system.

The system is enclosed by a boundary (that may be real or simply a "line"), so that the system can be open, closed, or isolated.

The system boundary may be real or hypothetical.

regions cartoon

Outcome

Distinguish between the universe, system, surroundings, and boundary