RC India

Hi all

My new self Design 10 Blade 71mm EDf fan

Thrust 950 gram on 4S & 1.2KG on 5S Lipo battery
Weight of EDF ---104 Gram
Thrust Vs Power ratio --2.37
Motor --2750Kv
4S-5S Lipo

Thanks
Samant Mishra
9888460199
 

My self design 71 EDF Sound like a jet engine.

https://youtu.be/n-DcTgIZTLQ

@Samant Mishra,

Nice.
How much total static thrust?
How much specific thrust (gms/watt)?
How does it compare with a commercially available equivalent?

More importantly, how did you make the impeller?

Regards

Static thrust on

4S Lipo battery  ---950gram
5S Lipo battery ----1.2Kg
Gms/watt  ratio -----2.37

As commerical available EDF  which run on 4S consume higher current 40Amps & above & require ESC of above 50Amps
so you can assume the power consuption is about 840 watt or may be more because of that flight time of model have huge impact.

the motive of designing EDF

1) To reduce Current consuption
2) improve flight timimg
3) Improve the efficieny of ducted fan

Designing a ducted fan is itself a challenge for me several design i have tried but fail to acheive the desired result, so finally i have decided to consult my one of the friend who is good in CFD simulation, we have run our cad file in the  simulation many time & make the changes in design accordingly & result is in front of you.

Thanks & Regard
Samant Mishra

Some rough calculation i have used in excel


EDF Thrust Calculation                     
Parameters   MM      Meter         RPM   
Pie   3.142               37000   
DH   27                  
RH   13.5                  
DT   71                  
RT   35.5                  
PH   84.834      0.0848   m/r      616.6666667   r/s
PT   223.082                  
Velocity         52.3143   m/s         
                     
Area of fan Tip   3959.71   mm2   0.00339   m2         
Area of fan Hub   572.63   mm2               
                     
Volume of air Flow         0.1772   m3/s         
                     
Mass of Air by volume         1.2250   kg/m3         
                     
Change in Mass of Air         0.1772   kg/s         
                     
F=MA                     
                     
F         9.2697   kgm/s2         
Thrust         945.23   gramm         
                     
                     
P=FV                     
                     
Power consuption         383   watt         

Thanks & Regard
Samant Mishra

Very interesting, though beyond my grasp!

How does the actual test compare with the theory predictions?

See the dimension given in the calculation is same which i have used in the EDF and  the actual test parameter have the accuracy of 95% with respect to the theoretical calculation. But very important part is blade aerofoil selection and the blade angle at tip and hub play important role in the thrust vs watt ratio more the ratio more will be the efficiency of ducted fan.

Thanks and regard
Samant

Hi

All if any one want to buy 10 blade edf or its parts
Can contact me.
samant.mishra434@gmail.com
9888460199

Nice

Hi to all

plz revert if any one have the solution of below problem

On Parallel connection of EDF the thrust is reducing by 30%  i am using below configuration

two nos 40A ESC
and one battery pack of 2200MAH lipo battery of 40C/80C ratting
at full throttle my single EDF consume 23A current at 16.8Volt (4S) & produce 1020gm thrust but when i am running twing EDF on single battery pack it producing 1430grm thrust only

current consuption when running twing EDF 46A & voltage 16.8(40S) thrust output 1430grm only.
 
Thanks
Samant Mishra

First check if the second EDF by itself produces 1000gms+ at 16.8v and 23A.

Then check your lipo voltage under full throttle load of both EDFs. Maybe well below 16.8!

Regards

Thanks for Replying Mr. KK Iyer

I have individually check both the EDF they are producing 1020grm of thrust at full throttle.

& AMPS consuption is also getting double during running both the EDF at same time 23+23 =46 AMP as per the watt meter reading


The test which i have conducted after full charging of battery pack & measured the thrust with in first 15 second  of run.

Thanks & Regard
Samant

Check the lipo VOLTAGE under full load.
At 46 amp draw, the voltage drop will be twice as much as at 23 amps.
If you have tach, you can check the rpm too.
Regards