[General] Fwd: Drag torque

[Ethan Chew]

Good Evening,

       I was wondering if you guys could help an inquiring young mind.
 Eric would like to know how to calculate the drag torque of a cylinder
rotating on a shaft (wheel and axle configuration in picture attached).  He
will be applying a certain torque to rotate the assembly and is seeking a
general equation that would tell him for the certain torque what the
rotational velocity would be after a certain time, its maximum rotational
velocity and how long it would take to reach it.
       Help would be appreciated.  Thanks!

               - Ethan/spacefelix

---------- Forwarded message ----------
From: Eric Chew <ericchew24 at gmail.com>
Date: Sat, Jan 14, 2012 at 8:44 PM
Subject: Re: Drag torque
To: Ethan Chew <spacefelix at gmail.com>


Hey!

So here's a simple picture of what I'm doing.

Pretty much, I'm trying to rotate a cylinder on an axle, as shown in the
picture. I will be applying a certain torque on it, and I wanted to find a
general equation that would tell me what the velocity would be after a
certain time and also what the maximum velocity it could reach would be and
how long it would take to reach it.

I talked with my physics teacher, and she told me that the equation I put
on the paper would give me a general idea, but that calculating the drag
torque would be difficult and that she didn't know how to. I tried looking
on my own and found a lot of equations for drag force when something is
moving, but nothing on when something is rotating in place. Do you know of
an equation for the drag torque? Or could you help me derive one?

Thanks,

Eric Chew


On Sat, Jan 14, 2012 at 4:49 PM, Ethan Chew <spacefelix at gmail.com> wrote:

> Hello!
>
>       This is my business/technical contact.  Please use this e-mail only
> for technical and business communication.  That being said, can you send me
> a drawing of your device and how it operates so I may understand how it is
> being loaded?
>
>              - Ethan
>
> On Sat, Jan 14, 2012 at 1:44 PM, Ethan Chew <eflyingfelix at gmail.com>wrote:
>
>>
>>
>> ---------- Forwarded message ----------
>> From: Ethan Chew <eflyingfelix at gmail.com>
>> Date: Sat, Jan 14, 2012 at 1:44 PM
>> Subject: Fwd: Drag torque
>> To: Ethan Chew <eflyingfelix at gmail.com>
>>
>>
>>
>>
>>
>>  ---------- Forwarded message ----------
>> From: Eric Chew <ericchew24 at gmail.com>
>> Date: Sat, Jan 14, 2012 at 10:35 AM
>> Subject: Drag torque
>> To: Ethan Chew <eflyingfelix at gmail.com>
>>
>>
>> Hey Ethan,
>>
>> I was wondering if you knew how to calculate the drag torque of a solid
>> cylinder, given the radius, width, and mass of it, while it rotates on an
>> axle in the air.
>>
>> Thanks,
>>
>> Eric Chew
>>
>>
>>
>
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