JSAMVTOL
May 14, 2007, 09:52 PM
Join Date: Oct 2006
Posts: 43 Discussion - EDF-Physics & Superchargers
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I was curious about maintaining and/or boosting edf elec.motor/fan efficiency (lbs/ft thrust) by using a separate supercharger (smaller edf fan/duct) as the compressor.
Q: Would this in theory increase mass flow?
Based on basic edf thrust equation: mass flow x velocity = thrust
I realize fan inlet area / ambient temp. and density plays a factor, so
Q1. Decrease inlet air density with wator vapor. Less dense air.(water vapor when mixed in air pushes out nitrogen and other gases that are heavier, it replaces them as they move back into the free stream) Less air density means reduced drag on fan enabling more rpm at constant power?? am i close?? :eek:
Q2. How do you get wator vapor from a smaller edf supercharger without weight penalties? :confused:
3. What if the inlet air was cooled (less or equal to exit air tem), had low density (due to wator vapor) and increase in charged air (increased mas flow from smaller edf supercharger of about 1.5psi). :cool:
Could this work?? or would the weight penalties from supercharging with intercooling mitigate any increase in edf efficiency. :(
Really curious
Thanks
JS
Posts: 43 Discussion - EDF-Physics & Superchargers
--------------------------------------------------------------------------------
I was curious about maintaining and/or boosting edf elec.motor/fan efficiency (lbs/ft thrust) by using a separate supercharger (smaller edf fan/duct) as the compressor.
Q: Would this in theory increase mass flow?
Based on basic edf thrust equation: mass flow x velocity = thrust
I realize fan inlet area / ambient temp. and density plays a factor, so
Q1. Decrease inlet air density with wator vapor. Less dense air.(water vapor when mixed in air pushes out nitrogen and other gases that are heavier, it replaces them as they move back into the free stream) Less air density means reduced drag on fan enabling more rpm at constant power?? am i close?? :eek:
Q2. How do you get wator vapor from a smaller edf supercharger without weight penalties? :confused:
3. What if the inlet air was cooled (less or equal to exit air tem), had low density (due to wator vapor) and increase in charged air (increased mas flow from smaller edf supercharger of about 1.5psi). :cool:
Could this work?? or would the weight penalties from supercharging with intercooling mitigate any increase in edf efficiency. :(
Really curious
Thanks
JS