Conversion of Fluid Rotational Force to Rocking Motion

In summary, the conversation discusses the process of converting parameters from centrifugal force calculations to determine equivalent parameters for a bag of fluids on a rocker. The known parameters for the bag of fluid include its mass, range of speed, and range of angle. The conversation also explores the possibility of using a paint shaker as an alternative to rotating and shaking a flask for mixing. However, it is noted that complex fluid motion is necessary for efficient mixing. Ultimately, the conversation ends with the acknowledgement that there are constraints in place and the search for a solution to make the process translatable.
  • #1
akwok
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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!
 
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  • #2
I don't understand the question to be honest. Could you explain this with more detail?
 
  • #3
Or perhaps an informative drawing ?
 
  • #4
akwok said:
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?

1639847429578.png

https://www.fishersci.com/shop/products/fisher-scientific-nutrating-mixers-fixed-speed-1/p-5470767#?keyword=
 
  • #5
berkeman said:
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.
 

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  • #6
BvU said:
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.
 

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  • #7
akwok said:
currently using a mixer that rotates clockwise
Sorry, how does rotating a fluid filled container cause efficient mixing?
 
  • #8
berkeman said:
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.
 
  • #9
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.
 
  • #10
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.

akwok said:
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.
 
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  • #11
jrmichler said:
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!
 
  • #12
Arjan82 said:
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!
 

FAQ: Conversion of Fluid Rotational Force to Rocking Motion

What is the conversion of fluid rotational force to rocking motion?

The conversion of fluid rotational force to rocking motion is a phenomenon that occurs when a fluid, such as water or air, exerts a rotational force on an object, causing it to move in a rocking motion. This is commonly seen in boats or ships, where the force of the water against the hull causes the vessel to rock back and forth.

How does this conversion occur?

This conversion occurs due to the Bernoulli's principle, which states that as the velocity of a fluid increases, its pressure decreases. In the case of a boat or ship, the water flowing around the hull creates a difference in pressure, with higher pressure on one side and lower pressure on the other. This pressure difference causes the vessel to rock as the water pushes against the hull.

What factors affect the conversion of fluid rotational force to rocking motion?

The conversion of fluid rotational force to rocking motion can be influenced by several factors, including the shape and size of the object, the speed and direction of the fluid flow, and the density and viscosity of the fluid. Other factors such as the angle of the object and any external forces acting on it can also affect the conversion.

Can this conversion be harnessed for practical use?

Yes, this conversion can be harnessed for practical use in various applications. For example, in hydroelectric power plants, the force of flowing water is converted into rotational motion, which is then used to generate electricity. In sailing, the force of the wind on a sail is converted into a rocking motion to propel a boat forward.

Are there any potential drawbacks to this conversion?

One potential drawback of this conversion is the potential for instability or loss of control, especially in larger vessels. The rocking motion can also cause discomfort or seasickness in passengers. In some cases, the conversion of fluid rotational force to rocking motion can also cause damage to the object or its surroundings, such as erosion of riverbanks due to the force of flowing water.

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