Q: Fluid drainage along the outside of an inclined cylinder

  • Thread starter Thread starter Andy Resnick
  • Start date Start date
  • Tags Tags
    Fluid dynamics
AI Thread Summary
The discussion focuses on fluid drainage along the outside of an inclined cylinder, particularly in the context of rainwater transport on trees. The flow rate of rainwater is influenced by rainfall intensity and the tree's structural characteristics, such as inclination angle and surface roughness. The analysis of fluid dynamics is complicated by factors like solute transport from tree components into the water. Participants suggest starting with experimental data to understand flow rates and patterns better. The conversation highlights the need for references and models to aid in this complex study of water drainage dynamics.
Andy Resnick
Science Advisor
Education Advisor
Insights Author
Messages
7,682
Reaction score
3,746
TL;DR Summary
Looking for references analyzing fluid drainage along the outside of an inclined cylinder
Asking on behalf of a colleague who is studying rainwater transport/drainage in the context of plants (trees, mostly):

There's a lot of published work analyzing the flow of fluid within a tube, or along an interior corner. I can't seem to find much of anything about the flow of water along the outside of a cylinder- think rainwater on a cable. Clearly interfacial energy has a lot to say about how much water is transported along the cable and how much drips off onto the ground. I guess a pendant drop analysis is a reasonable starting point, but the contact line isn't pinned as the usual case.

Has anyone worked out the fluid dynamics?

Just hoping someone can point us in the right direction for a literature search. Thanks in advance!
 
Engineering news on Phys.org
Andy Resnick said:
TL;DR Summary: Looking for references analyzing fluid drainage along the outside of an inclined cylinder

Asking on behalf of a colleague who is studying rainwater transport/drainage in the context of plants (trees, mostly)
Interesting question.

Can you provide a bit more context? What is the flow rate of the rainwater, and what are the dimensions and incline angle of the trees? Are you wanting to figure out how much water falls off of the inclined tree? Are you trying to optimize how much of the runoff you can collect in a cistern near the base of the tree?
 
berkeman said:
Interesting question.

Can you provide a bit more context? What is the flow rate of the rainwater, and what are the dimensions and incline angle of the trees? Are you wanting to figure out how much water falls off of the inclined tree? Are you trying to optimize how much of the runoff you can collect in a cistern near the base of the tree?
I can try and answer these...

The flow rate is (most likely) driven by the rate of rainfall, and my colleague, and environmental scientist, is interested in how solutes from the tree (leaves, bark) dissolve into the water and are transported elsewhere- to other parts of the tree, to runoff, etc. So there's a range of inclination angles and 'cylinder' radii (abaxial surface of leaf vasculature/stems/branches/trunk).

At this point, he's just looking for some 'reference frame' to build a model, any quantitative results would be helpful.
 
Others will have better replies, but I wonder if it might be good to start with some experiments to gain some insights. Certainly the type and surface roughness of the bark will make a difference, in addition to the branch diameter and inclination angle. At least with the experimental data, they could start to get some ideas of the flow rates for all the different parts of the tree. Wow, complicated problem.
 
Andy Resnick said:
The flow rate is (most likely) driven by the rate of rainfall, and my colleague, and environmental scientist, is interested in how solutes from the tree (leaves, bark) dissolve into the water and are transported elsewhere- to other parts of the tree, to runoff, etc.
Drops that fall to the side, will flow to that side, but with an elliptical slope due to the section of a sloping cylinder.

Drops that fall on the upper central axis will flow down the axis, but as flow volume increases, that flow will radiate out to the sides, then flow down the elliptical side.

The water that wraps around under the cylinder will [converge and] flow down the lower axis until film thickness, or surface roughness, [detaches it, and] drops it to a cylinder below, or to the ground.

[edited]
 
Last edited:
How did you find PF?: Via Google search Hi, I have a vessel I 3D printed to investigate single bubble rise. The vessel has a 4 mm gap separated by acrylic panels. This is essentially my viewing chamber where I can record the bubble motion. The vessel is open to atmosphere. The bubble generation mechanism is composed of a syringe pump and glass capillary tube (Internal Diameter of 0.45 mm). I connect a 1/4” air line hose from the syringe to the capillary The bubble is formed at the tip...
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'
Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
I'd like to create a thread with links to 3-D Printer resources, including printers and software package suggestions. My motivations are selfish, as I have a 3-D printed project that I'm working on, and I'd like to buy a simple printer and use low cost software to make the first prototype. There are some previous threads about 3-D printing like this: https://www.physicsforums.com/threads/are-3d-printers-easy-to-use-yet.917489/ but none that address the overall topic (unless I've missed...

Similar threads

Replies
45
Views
5K
Replies
8
Views
2K
Replies
4
Views
8K
Back
Top