Originally Posted by markdrela
Thrust = mass_flow_rate * (Vexhaust - Vflight)
Mark, how did you arrive at this equation?
It's part of the continuity equation, a rewriting of Newtons second law, you can see here:
Near the bottom of the page, under usage.
The equation Mark gave ignores the acceleration term.
The velocity term gives you a linear relationship, from maximum attainable thrust at 0 airspeed, down to zero thrust at whatever the exhaust velocity itself is.