How do you stop smoke generation? I am trying to do a smoke/fire simulation.  I can get "ignition" by setting the Start frame for the Smoke Cache bake.  I want the fire to "go out" and the last generated smoke to still drift upwards.    Think of a candle going out.  The last of the smoke still rises for a moment.  Setting the End frame for the smoke cache bake simply freezes the last simulation step.  How can I get smoke/fire to cease being generated without freezing the simulation?
You can keyframe the Density parameter on the flow object to make it start and stop emitting smoke.