By a “Blockchain Simulator” if you mean a test environment where you can test different methods prior to executing them on a live blockchain where its impacts bear large-scale effects by trial and error, then certainly there are a couple of options you could try out.
IBM Hyperledger: The IBM hyperledger eliminates the need for miners by providing an interface where the consensus is derived by 51% majority of independently run servers. IBM’s hyperledger program is fairly easy comparatively and makes use of Chain-code to deliver and execute contracts. One might consider using the free developer version prior to developing one.
Ethereum Test Net: As is the case with any entity that bears long-term change effects on usage, Ethereum provides a test net where one could test their application to make sure it is functional and behaving as expected. Since directly deploying contracts on the publicly live blockchain could have irreversibly drastic effects this is extremely important.
Bitcoin Testnet: Bitcoin protocol allows a test net where people can test their application to make sure it is functional and behaving as expected. Since directly deploying contracts on the live blockchain could have irreversibly drastic effects this is an important step.
Testnets are valuable to developers for testing purposes because they have no value.
Multichain: Multi-chain is by far the cheapest method to deploy a live blockchain. It is so cheap that you could deploy two on your own machine, one as a test and one as a live version. Feel free to experiment with both. Multichain, however, provides the ability to execute smart contracts through a method called streams and it employs a different protocol compared to the rest.
Addendum: Each Blockchain testing simulator employs a different protocol inherent to its own and sufficiently different from the rest. There are numerous other methods by which one could feature a fully fledged testing scenario, but among the ones that I’ve worked with, I happened to find these more fruitful than the rest.