What Happens If You Block a Fan with a Drag Tube?

  • Thread starter EngineerAhmad
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In summary, if a drag tube is trapped before a fan, the motor will experience less load and the current draw will decrease. However, this can only be done with certain types of fans and should not be done for an extended period of time as it can cause the motor to overheat and fail.
  • #1
EngineerAhmad
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Hi every body..
Say you trapped the drag tube before a fan, what would happen then?
Will the Amber decrease?
Will the motor be heated ?
Why?

Please I need reasonable replies ..
 
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  • #2
EngineerAhmad said:
Hi every body..
Say you trapped the drag tube before a fan, what would happen then?
Will the Amber decrease?
Will the motor be heated ?
Why?

Please I need reasonable replies ..
It is not possible to give a reasonable reply without knowing more about the size of the drag tube, its orientation, the size of the fan.

What does one mean by trapping the tube before the fan?

What amber?

A motor would heat if there was more mechanical resistance to it. Most motors are designed for a particular speed.
 
  • #3
Say the fan is put in a tube which have the same size of it, then we trapped the tube before this fan, that no new air can be drawn.
Would the motor have less load (then the Amber of the fan motor will decrease) or the motor would be heated?
I.e: Would the load increase or decrease and why do everybody say the motor would break up?
 
  • #4
Oh, I get it.

You can't really do this with an ordinary fan, since the enclosure which keeps you from accidentally contacting the blades allows enough space for air to circulate past. But, you can do this with a vacuum cleaner; if you put your hand over the intake, you can actually hear the result: the motor speed increases, since there is less drag on the impeller. In the meantime, however, the current draw (the word you want here is not "amber" it's "amperage) actually decreases. You don't want to run the motor for very long in this condition, though, because it is designed to be cooled by the airflow. Eventually the windings would overheat and fuse and the motor quits.
 

1. What is a drag tube?

A drag tube is a device used in aerodynamics to measure the drag force on an object. It is typically a long, narrow tube with one end open and the other end connected to a pressure gauge. When air flows through the tube, it creates a difference in pressure between the two ends, which can be used to calculate the drag force on the object.

2. How does blocking a fan with a drag tube affect the airflow?

Blocking a fan with a drag tube creates an obstruction in the airflow, which can change the characteristics of the airflow. This can result in changes in the pressure and velocity of the air, which can affect the drag force on the object being tested.

3. Can blocking a fan with a drag tube affect the accuracy of the measurements?

Yes, blocking a fan with a drag tube can affect the accuracy of the measurements. The obstruction in the airflow can cause turbulence and alter the pressure and velocity readings, leading to inaccurate results. It is important to ensure that the drag tube is properly positioned and does not block the fan's airflow.

4. What happens if the drag tube is not placed correctly while blocking the fan?

If the drag tube is not placed correctly, it can block too much or too little of the fan's airflow, resulting in inaccurate measurements. It is essential to carefully position the drag tube to ensure it does not interfere with the airflow and accurately captures the drag force on the object.

5. Are there any other factors that can affect the measurements when using a drag tube to block a fan?

Yes, there are other factors that can influence the measurements when using a drag tube to block a fan. These include the distance between the fan and the object, the speed of the fan, and the shape and size of the object being tested. It is crucial to consider and control these factors to obtain reliable and accurate results.

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