THE ELECTRIC DUCTED FAN.( E.D.F.)

The Great Planes Hyperflow E.D.F.

SPECIFICATIONS
Stock Numbers:
    GPMG3910 without Motor
    GPMG3911 with Motor
Housing Diameter: 2.23 in (56 mm)
Housing Length: 1.5 in (38 mm)
Total Length w/cone: 4.25 in (108 mm)
Weight fan system only: 1.3 oz (37 g)
Weight w/370 Brushed Motor: 3.85 oz (109 g)
Weight w/Ammo™ Brushless Motor: 3.57 oz (101 g)
Motor: 370 BB Brushed motor (included with GPMG3911 only)

Depending on the motor used, The efflux speed of this unit can be up to 165MPH!- with a thrust of 28.9 oz.

For further information on this unit, please click here.

The recent improvements in electric motor and Li-Po battery technology have enabled the development of electric ducted fans to reach fantastic levels of performance. The secret is in the RPMs available. Now revs can be close to 50.000RPM. This results in high thrust to weight ratios, that in turn gives true jet-like performance.

This chart shows how thrust increases as RPM increases.

To ensure that all the thrust developed is used to fly the model, the intake and efflux areas must be large and the duct must be smooth.

The critical area is the swept area of the fan blades. For the Hyperflow unit the Fan Swept Area (FSA) equals 2.74 square inches.(17.68 square cm) If a straight intake tube were to be used, then the entry area would be 134%FSA. The exit or efflux area should be between 90 and 99%FSA. So if you are designing your own EDF jet, or trying to improve the performance of a purchased jet, then measure these dimensions as accurately as you can and check the ratios.

More information can be found in the Hyperflow manual-click here to view it.

When selecting a ducted fan jet model, I look at the all-up weight, of the finished model and ensure that the total thrust of the fan(s) is close to, or even exceeds, this figure. Also consider the wing area. A small wing will mean a high wing loading, The larger wing area translates into a better handling model that flies better at low speeds. This last attribute is particularly important during landing!

The RC Lander Ducted Fan.

The photo at left shows the RC Lander Electric Ducted Fan. This unit is constructed mainly from aluminum alloy.

This unit is 68 mm (2.67inches) diameter and incorporates a 5 bladed fan. RPM can be as high as 47,000 with a maximum thrust of 1.6 kg(3.52lb)

Maximum RPM is 47,000.

This unit is available from NitroPlanes.

Click on the icon to visit NITROPLANES.com and at "Find a Product" type in "RC Lander EDF Metal Fans" This will take you to a page with the RC Lander ducted fans listed. The pricing varies from $106.95 to $129.95 depending on brushless motor specifications.

Jet Hanger Hobbies.

This web site has everything for the jet flyer! Whether your interests are Electric Ducted Fans or Glow engine powered Ducted Fans or turbines. There is valuable information here. EDFs are offered from the smallest to the largest.

The E-TURBAX  electric ducted fan unit is 5 1/4 inches(133.3mm) outside diameter, with a 4 3/4 inch(120mm) diameter fan. Thrust can be 13-15 lbs, with an RPM of 30,000. This is certainly one of the largest units available.

Jet Hanger Hobbies have been involved in the design and flying of jets for a long time. Visit their site, by clicking here.

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