I was curious about the decision to increase the number of blade elements in T200 thruster to 3 from earlier 2. AFAIA 2 bladed thrusters are more efficient than 3. What are the advantages of increasing the blade number in terms of thrust performance? is there any other reason?
Hi @milindfernandes,
Two blades are not necessarily more efficient than three blades in all circumstances. In particular for the T200, in order to hit the thrust performance needed, a two bladed propeller would need to have such a steep pitch that three blades of a shallower pitch ended up being more efficient overall.
-Adam
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Thank you Adam. In hindsight I should have realized the range of voltages T200 works for unlike T100 and at almost twice the power.
the less blades, the faster you can go, the moore blades, the moore power/toque you can have… just like a Speedboat;)
Thanks Christian. As per what i have learned so far is that
- Low number of blades are suitable/required for high rpm/low torque( and low power) motors such as those on T100.
- Lower blade number implies higher top speed but lower acceleration for a given motor output.
- more blades imply lower top speed but higher low end thrust. Since for higher thrust at low rpm for 2 bladed prop would imply increasing its dia which would load the motor and would be less efficient than 3 bladed prop with lower dia.(or steep pitch as Adam mentioned)
- less number of blades have higher efficiency due to low torque (which depends on total blade area), consequently more blades-> more drag, more torque → lower efficiency (torque here is the drag torque experienced by the propeller, which also increases with higher pitch)
- For high rpm motors 2 blades are better
- for low rpm motors with higher power (W) 3 blades seems to be sweet compromise between low end thrust and efficiency.
Am i wrong anywhere?