Timeline for Why does blocking a fan speed it up?
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 25, 2023 at 0:03 | comment | added | niels nielsen | You can quantify it closely by running the motor with the impeller removed, and noting the resulting RPM. this is the unloaded RPM case. if the motor is unloaded, it will be performing almost no work and hence will be consuming almost no power- just spinning at the speed where its induced back voltage equals the mains voltage, and current falls to a low value. | |
| Jan 24, 2023 at 22:12 | comment | added | Redirectk | Is it possible to quantify the increase in RPM that the near-vacuum conditions would cause? Or is it highly dependent from the motor itself? I am asking because I am curious why vacuum cleaners do not control the motors in such a way that RPM remain constant under different conditions. The pitch increase is quite noticeable so I would assume the increase in RPM is also quite big, which in turn means the motor is under more stress | |
| Jan 23, 2023 at 0:34 | comment | added | niels nielsen | @benjimin, it means the airflow no longer follows the contours of the fan blades, but has separated from the blades, creating turbulence and thrash instead of accelerating the air. | |
| Jan 22, 2023 at 21:02 | comment | added | benjimin | Could you expand on the meaning of stall in this context? | |
| Jan 22, 2023 at 19:21 | history | answered | niels nielsen | CC BY-SA 4.0 |