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View Full Version : Help! Ducted Fan Ducting

Greg Evershed
Mar 19, 2002, 01:39 AM
Has anyone done any experimenting with the cross sectional area of electric ducted fan ducting?

A full size turbine engine moves a small volume of air over a large speed range. And if a ducted fan works on the principal of moving a relatively "large" volume of air over a small speed range.

Could the efficiency of our electric ducted fans not be improved by installing the fan in a venturi? I remember reading an ezone article saying that the inlet diameter should be 110% larger than the fan area and the outlet diameter 90% of the fan area for optimal thrust....But that would not be compatable with the ventury theory??? :confused:
tampasis
Sep 23, 2005, 10:24 AM
THE A7 DUCTED FAN RC PLANE IS GREAT, FAST AND GLIDES SMOOTH
MAKE SURE YOU BEND UP THE ELEVATOR LEFT AND RIGHT UP ABOUT 2 DEGREES.
HAND LANCH AND HAVE FUN THIS IS A 2 CHANNEL RC BUT IT REALLY FLIES WELL THE ONLY DRAW BACK IS ABOUT 4 MIN. FLYING TIME THEY NEED TO PUT IN LiT BATTERIES TO GET AT LEAST 10 MIN ON A FLIGHT. WHEN YOU FLY IT MAKE SURE YOU ARE AT LEAST 50 FT UP BEFORE TURNING LEFT OR RIGHT ALTITUDE IS CONTROLLED BY ENGINE SPEED SAME AS A REAL PLANE. JET FLIGHT ON THE CHEAP ABOUT $89.00 FROM WWW.RCDISCOUNTS.COM
AND THEY ARE IN STOCK ALSO BUY AN EXTRA BATTERY FOR NOW IT ONLY TAKES ABOUT 10 MIN TO RECHARGE ON A CAR CIG LIGHTER
cad4u dt
Oct 05, 2005, 04:38 PM
A manufactured model edf jet is designed with inlet and outlet air movement calculations incorporated. The modeler should only be concerned with the models ready to fly weight. One could examine the smoothness of the outlet duct. The smoother it is the less drag it will create. The inlet duct should also be smooth but mainly the leading edge of the duct should resemble the leading edge of the wing. blunt leading edges will creat turbulance that will intifier with clean air flow. This can also effect air flow through the fan unit.
If you are a fun flyier follow the manufacturs instructions, keep it light and have fun. If a serious flyier refer to ducted fan tech. books and calculate tell your harts content and have fun.