Currently to my knowledge, there are no iOS simulators available. Historically:
1. Windows could virtualize Windows via VMware (and PowerPC versions of OSX via PearPC)
2. Apple ported the Macs to Intel; you could now dual-boot a Mac (Windows/OSX) or run Windows in a virtual machine (Parallels/VMware/Virtual Box)
3. Hackintosh used Windows computers to natively boot OSX; using the same techniques, people were able to virtualize OSX on Windows using VMware etc.
4. Android was officially ported to x86 for manufacturers (ex. Dell Venue 8 7000-series Android tablets running on Intel processors); alternatives for end-users were created, such as Android-x86 & ConsoleOS (and virtualized versions like Andy)
5. iOS is closed-source & ARM-based; there are no real emulators for Windows or Linux - they are all just GUI emulators that don't actually run iOS. The best simulator is probably iPadian, but all they do is rig up some games & apps and pretend to be a real emulator, but it's not. The best you can do is jailbreak a compatible iPad, install VNC or some other type of remote desktop service, and connect remotely to it from the Windows machine. Closest thing you can do is get a Mac (or Hackintosh), download Xcode, and run an iOS simulator for developmental purposes: (iirc you have to have access to the source code to do so, i.e. compile & run, because it translates it for the Intel CPU instead of the ARM hardware foundation)
https://developer.apple.com/library/ios/documentation/IDEs/Conceptual/iOS_Simulator_Guide/
TL;DR - no, there are no real virtual machines for iOS.