How do I calculate the yield pressure for a Bingham plastic in a tube?

Click For Summary

Discussion Overview

The discussion revolves around calculating the yield pressure for a Bingham plastic in a tube, exploring the engineering of liquids with specific yield stresses, and identifying suitable materials for such applications. It encompasses theoretical and practical aspects related to fluid mechanics and material science.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Participants inquire about the calculation of yield pressure for Bingham plastics, specifically how to determine the pressure difference required for flow based on tube dimensions and yield stress.
  • Some participants express uncertainty regarding the availability of tailored liquids with specific yield stresses, noting difficulties in finding suppliers or formulations that meet their criteria.
  • There is mention of the potential for engineering liquids with specific yield stresses, with suggestions to explore Bingham plastics and dilatant fluids as possible avenues.
  • One participant highlights the challenge of finding non-suspension liquids that exhibit the desired yield stress range of 150 Pa to 250 Pa while maintaining low viscosity.
  • Another participant suggests that most Bingham plastics are typically suspensions and mentions drilling mud as an example, indicating a need for materials that can form gels.

Areas of Agreement / Disagreement

Participants generally agree on the complexity of calculating yield pressure and the challenges associated with finding suitable materials. However, there is no consensus on the feasibility of engineering specific yield stresses or the types of materials that could be used.

Contextual Notes

Participants note limitations in available information regarding tailored liquids, with references to general knowledge and specific examples like ketchup and drilling mud. There is an acknowledgment of the need for further exploration into chemical formulations and supplier catalogs.

Peter Hessellund
Messages
11
Reaction score
0
I have three questions.
1. How do I calculate the yield pressure for a Bingham plastic in a tube if I am given:
Length of tube
Diameter of tube
Yield stress of liquid

2. Is it possible to engineer a liquid to have a specific yield stress ?
3. What kind of material would be suited for engineering a specific yield stress? Could it be done with silicon oils or could it be done with additives to water?
 
Engineering news on Phys.org
Peter Hessellund said:
I have three questions.
1. How do I calculate the yield pressure for a Bingham plastic in a tube if I am given:
Length of tube
Diameter of tube
Yield stress of liquid

2. Is it possible to engineer a liquid to have a specific yield stress ?
3. What kind of material would be suited for engineering a specific yield stress? Could it be done with silicon oils or could it be done with additives to water?
I don't quite understand your first question. Are you asking how much of a pressure difference is required before the bingham plastic begins to flow?
 
  • Like
Likes   Reactions: Peter Hessellund
Yes I am asking how much pressure difference is required for flow. I think that I have read somewhere that a larger initial pressure is required for small diameters.
 
Hi Chester
You already answered the first question for me. I was googeling yield pressure and getting nothing. The right words were the ones you used in your reply to me:)
I still need answers for the two last questions.
The formula is:
upload_2016-12-29_7-33-22.png

Found in this PDF
http://onlinelibrary.wiley.com/doi/10.1002/9780470516430.app7/pdf
 
Peter Hessellund said:
Hi Chester
You already answered the first question for me. I was googeling yield pressure and getting nothing. The right words were the ones you used in your reply to me:)
I still need answers for the two last questions.
The formula is:
View attachment 110883
Found in this PDF
http://onlinelibrary.wiley.com/doi/10.1002/9780470516430.app7/pdf
Nicely done. For questions 2 and 3, I recommend that you google Bingham plastics and dilatent fluids and see what you come up with.
 
Hi Chester

I have already been googeling for hours on question 2 and 3 but the only thing that comes up is general stuff about ketchup or specific stuff about solving the governing equations or simulations. I have so far been unable to find a nice catalogue from a supplier producing a liquid with the desired yield stress or a company claiming to be able to make tailor made liquids with the desired properties. I have not been able to find a chemical formulation of a liquid with at attached yield stress number at all. I am looking for a liquid with a yield stress in the range of 150 Pa to 250 Pa with as low a viscosity as possible or maybe even a shear thinning liquid. The liquid can not be a suspension.
 
Peter Hessellund said:
Hi Chester

I have already been googeling for hours on question 2 and 3 but the only thing that comes up is general stuff about ketchup or specific stuff about solving the governing equations or simulations. I have so far been unable to find a nice catalogue from a supplier producing a liquid with the desired yield stress or a company claiming to be able to make tailor made liquids with the desired properties. I have not been able to find a chemical formulation of a liquid with at attached yield stress number at all. I am looking for a liquid with a yield stress in the range of 150 Pa to 250 Pa with as low a viscosity as possible or maybe even a shear thinning liquid. The liquid can not be a suspension.
Ugh. Most Bingham plastics are typically going to be suspensions. I was thinking of something like drilling mud, which is a suspension of bentonite clay particles. You need to find something that forms a gel, so maybe something with polar molecules with ends that attract. Unfortunately, this is about all that I can help. I don't know much more.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 8 ·
Replies
8
Views
2K
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 10 ·
Replies
10
Views
2K
Replies
22
Views
3K
  • · Replies 15 ·
Replies
15
Views
5K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 7 ·
Replies
7
Views
8K