So I am making my own EDFs that are 3D printed. The inside volume of the tube is 412,132 cubic millimeters I believe: Inner diameter is 80mm and length was 82mm
The hub diameter is: 40mm
Calculated FSA: 69.28
I’m using a standard 9v dc motor.
The calculated Kv for this motor is approximately 2,222
The calculation I found was:
Thrust = Mass flow rate * (Exhaust Velocity - Free Stream Velocity)
I went to calculate for mass flow rate as a start but that requires velocity and I can’t find a resource that tells me how to calculate for velocity without asking for mass flow rate which requires Velocity to calculate for 🤦♂️ .
Is that the velocity that the motor/fan spins at or is it the velocity that the air moves through the fan, or is it something else?
I know the density of the fluid is a part of that Velocity calculation and the Mass Flow Rate calculation. Given the fluid is just air I found that it’s 12.01 Pascals at sea level. I’m about 157ft above sea level.
I will then need to find Free Stream and Exhaust Velocity and I am not sure how to do that!
Can you give me an equation that gives me Thrust that uses any combination of only: motor RPM, motor Kv, Tube Volume, FSA, Wattage Motor Uses, number of rotors, Diameter of interior EDF tube, Diameter of Hub, Voltage, Air density, length of EDF.
I have the numbers for all these and that should be enough, that’s a lot of details.
If not can you explain what Velocity it’s talking about and also what Exhaust and free stream velocities are?