Two Ducted Fans For More Thrust

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Using two ducted fans, one at the intake and one at the exhaust, can potentially increase thrust by allowing the exhaust fan to further accelerate the air from the intake fan. However, the effectiveness of this setup largely depends on the specific fans used and the design of the duct. If the fans are fixed-speed axial types and the pressure drop is minimal, the thrust gain may be negligible. Understanding the pressure ratio between the two fans is crucial for optimizing performance. Preliminary actuator disk theory analysis can provide insights into the expected outcomes of this configuration.
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If you have a cylinder with a slightly larger diameter at one end (the intake end) Would having one ducted fan powered by it's own motor at intake end and a second ducted fan powered by it's own motor at the exhaust end produce more thrust? It seems like the already accelerated air coming from the intake fan would be "super accelerated" by the exhaust ducted fan? I purposely stated using two fans for reasons of experimenting/controlling fan RPMs separately and also my final design may not be a straight cylinder. The diameter of fans would probably need to be at least 12 inches for the power I'd need. Any suggestions by folks with real experience with larger ducted fans would greatly be appreciated.
 
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It depends on the the fans and duct. If the fans are fixed-speed axial and the pressure drop is low, there won't be much of an impact.
 
One thing you need to know, as was stated earlier, is the pressure ratio of the two fans. You can perform a preliminary actuator disk theory analysis
 

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