A model is a representation of a real object

in order to visualize and study its behavior and the way it looks (appearance),

and simulation is a process of changing from a mathematical or computer model

to a description of the system behavior based on a set of input parameters.

Modeling and simulation is important in

engineering because description of the system behavior by experimentation may

not be possible due to

§ The experiment may be too

expensive

§ The experiment might be

too dangerous

§ The experiment might get

disturbed by some uncontrolled environmental conditions

§ An experiment can also

take a much longer time to finish which might not be compatible with the time a

person has.

Control or system engineers use process

control in order to get a precise and simple manipulated model by predicting

the real world observations. The mathematical equations used to describe a

system and predict the behavior is known as a mathematical model. The model is

also known as an operator that gives the relation between the input and output

signals, the input and output signals usually refers to the model and not to

the physical system. In order to control processes, the phenomena has to be

described first by using some equations, algebraic, differential or integral

which will give some results which are like the real system.

Recently modeling has become more important

because of the complexity in modern industrial processes. The search for the

best solutions using powerful computers needs mathematical models for all types

of simulations. So simulation is used in almost everything from simple control

of ovens to artificial satellites and ambitious enterprises one way or the

other. Today independent services for modeling exist within the frame work of

research and development.

TYPES OF MODELLING

TECHNOLOGICAL LEVEL. this level is used to construct the architecture of the system

of different-sub systems which are usually the simple components. On this level

the languages used for modeling give a normal description in the form of a

technological model. It is easy to be done but it only indicates how the schema

is made. This level of modeling the satisfaction of the model is not verified

and the physical models are not considered. It is also known as the black box

model.

THE

PHYSICAL LEVEL; this level of modeling uses an energy description of the

physical phenomena.