simulate, simulation

simulate: 

1. VERB

If you simulate an action or a feeling, you pretend that you are doing it or feeling it.

• They rolled about on the Gilligan Road, simulating a bloodthirsty fight.     
• He performed a simulated striptease.

2. VERB

If you simulate an object, a substance, or a noise, you produce something that looks or sounds like it.

• The wood had been painted to simulate stone.
  

3. VERB

If you simulate a set of conditions, you create them artificially, for example in order to conduct an experiment.

• The scientist developed one model to simulate a full year of the globe's climate.     
• Cars are tested to see how much damage they suffer in simulated crashes.

... Cobuild

1(a). To have or take on the appearance, form, or sound of; imitate.

1(b). To make in imitation of or as a substitute for. See Synonyms at imitate.

2. To make a pretense of; feign: simulate interest.

3. To create a representation or model of (a physical system or particular situation, for example).

... Am-Heritage

simulation: Thesaurus-WordNet3.0

1. the act of imitating the behavior of some situation or some process by means of something suitably analogous (especially for the purpose of study or personnel training)

2.  (computer science) the technique of representing the real world by a computer program; 

• "a simulation should imitate the internal processes and not merely the results of the thing being simulated" 
• = computer simulation

3. representation of something (sometimes on a smaller scale)

• = model
  

4. the act of giving a false appearance; 

• "his conformity was only pretending" 
• = pretending, pretense, feigning, pretence

... http://www.thefreedictionary.com/simulate, http://www.thefreedictionary.com/simulation