2.4　Simulation

When we study the laws of material movement and various natural phenomena,conduct scientific research or solve technical engineering problems,some special situations including large research objects,inappropriate changing processes or dangerous environments are often encountered.As a result,it is difficult to perform direct research and on-site measurement on these objects.Therefore,based on the similarity theory,people can create a similar model to imitate the actual situation in laboratories,which may reproduce,delay or accelerate the corresponding physical phenomenon or process of the object,then the research and measurement on the object can be realised.This method is called the simulation.Usually,simulation can be divided into physical simulation and mathematical simulation.(https://www.daowen.com)