Physical Model
Also known as physical models, which can be further divided into actual models and analog models.



Physical Model: A tangible representation, scaled down (or up, or the same size as the original system) according to similarity theory, such as aircraft models for wind tunnel experiments, hydraulic system experimental models, architectural models, ship models, and so on.

② Analog Models: In different fields of physics (mechanical, electrical, thermal, fluid dynamics, etc.), the variables within each system sometimes follow the same laws. Based on this common rule, models with completely different physical meanings can be created through analogy and inference. For example, under certain conditions, the pressure response of an air system composed of a throttle valve and a gas capacitor exhibits a similar pattern to the output voltage characteristics of a circuit made up of resistors and capacitors. Therefore, the air system can be simulated using a circuit, which is easier to experiment with.