I Conversion of Fluid Rotational Force to Rocking Motion

[akwok]

TL;DR Summary

Determining parameter equivalents for a bag of fluids sitting on a rocker from known parameters for fluid being mixed through centrifugal force

Does anyone know how to convert the parameters within constraints to equate rocking motion from fluid being mixed through consistent shaking?

What I am given:
Centrifugal Force Calculations:
mass = 0.25 kg
angular velocity = 12.57 rad/s
radius = 0.045 m

What is known about the bag of fluid on top of the rocker
mass of bag = 0.5 kg
Range of speed = 8-42 beats per minute
Range of angle = 4-10°

Is it even possible to get similar results within these constraints?

Thanks!

 

[Arjan82]

I don't understand the question to be honest. Could you explain this with more detail?

 

[BvU]

Or perhaps an informative drawing ?

 

[berkeman]

Summary:: Determining parameter equivalents for a bag of fluids sitting on a rocker from known parameters for fluid being mixed through centrifugal force

What is known about the bag of fluid on top of the rocker
mass of bag = 0.5 kg
Range of speed = 8-42 beats per minute
Range of angle = 4-10°

Something like this?

https://www.fishersci.com/shop/products/fisher-scientific-nutrating-mixers-fixed-speed-1/p-5470767#?keyword=

 

[akwok]

Something like this?

View attachment 294380
https://www.fishersci.com/shop/products/fisher-scientific-nutrating-mixers-fixed-speed-1/p-5470767#?keyword=

Something similar to this. My current situation is a mixing of fluid equivalent for a buffer where I am currently using a mixer that rotates clockwise, but want to transition to a rocker with the aforementioned constraints.

 

[akwok]

Or perhaps an informative drawing ?

Not sure if this makes the most sense, but the circle is from a transverse view and the platform rocker is from a coronal view.

 

[berkeman]

currently using a mixer that rotates clockwise

Sorry, how does rotating a fluid filled container cause efficient mixing?

 

[akwok]

Sorry, how does rotating a fluid filled container cause efficient mixing?

The assumption for the rotation mixing is that the agitation rate would be high enough through swirling to mix over long periods of time as rotating does not keep particles in the same field due to the shape of the container being that of a conical flask. When placed into experimentation, the mixing does occur, but I would like to place it into the system of rocking in a sterile bag instead of rotating/shaking in a flask.

 

[Arjan82]

So, if I understand correctly you want to know what parameters (speed, angle) of the rocker would give "similar" results as the rotation mixing? Similar meaning same time to mix a particular fluid?

I don't think there is a simple answer for this as the fluid is moving in a highly complex way (the more complex usually the better for mixing). You will have to experiment.

 

[jrmichler]

Would a paint shaker work? Lots of videos if you search paint shaker video. Here's a randomly selected video of a commercially available paint shaker that sets the paint can on its side and uses a rocking motion on a vertical axis: .

And a simple homemade paint shaker: . This one uses a rocking motion on a horizontal axis, with the paint can vertical.

through swirling to mix

If by swirling, you mean that the fluid undergoes a spinning motion, this generally does not work. Fluid spinning does not mix fluid. You need complex fluid motion, as @Arjan82 posted above.

It's been a while since I watched the paint shaker in the hardware store. My vague recollection is that they use two motions simultaneously - side to side plus rocking.

Note that paint shakers are designed to get a settled out pigment back into suspension in a viscous fluid. If your mixing needs are less difficult, the same concepts can be used by running at a slower speed.

 

[akwok]

Would a paint shaker work? Lots of videos if you search paint shaker video. Here's a randomly selected video of a commercially available paint shaker that sets the paint can on its side and uses a rocking motion on a vertical axis: .

And a simple homemade paint shaker: . This one uses a rocking motion on a horizontal axis, with the paint can vertical. If by swirling, you mean that the fluid undergoes a spinning motion, this generally does not work. Fluid spinning does not mix fluid. You need complex fluid motion, as @Arjan82 posted above.

It's been a while since I watched the paint shaker in the hardware store. My vague recollection is that they use two motions simultaneously - side to side plus rocking.

Note that paint shakers are designed to get a settled out pigment back into suspension in a viscous fluid. If your mixing needs are less difficult, the same concepts can be used by running at a slower speed.

Unfortunately, there are constraints (as posted above). I do understand that fluid motion works in a complex way, hence asking here if anyone knows of a solution that could make it translatable. We can only implement one system or the other. Thanks though!

 

[akwok]

So, if I understand correctly you want to know what parameters (speed, angle) of the rocker would give "similar" results as the rotation mixing? Similar meaning same time to mix a particular fluid?

I don't think there is a simple answer for this as the fluid is moving in a highly complex way (the more complex usually the better for mixing). You will have to experiment.

Similar results would mean the similar mixing of the fluid within the same time. This was the answer I was hoping not to see haha. Thanks though!