3 replies to this topic

[ColorMan]

i understand the difference between laminar and turbulent flow in both gases and liquids.

however, what if the substance is a solid that is moving due to an external source (ie. an auger). how does one account for this in heat transfer calculations?

[Andree]

If you consider a solid body then you can talk about the flow around it... Solids do not flow, they can be transported by auger in form of suspension (then you can treat this problem as flow of liquid having apparent viscosity as for suspension) or in form of granules (in this case the fluid mechanics equations do not apply)

I guess you probably mean not a solid but the flow of a very viscous polymer as in extruders - this is often a "creeping flow"...

Implications to heat transfer:
- heat transfer is ineffective
- high viscosity causes energy dissipation in flow and this leads to temperature increase (more cooling is necessary)

[ColorMan]

No, I am not talking about the flow of a very viscous polymer in an extruder.

I am talking about nylon pellets (3-5mm in diameter). i am devising a system to transfer heat from the pellets, through stainless steel, and into water. i have all of my "knowns" for water and stainless steel.

An auger will move these pellets at a rate of about 1.5 meters/hour.

but i am not sure how to handle the solid nylon pellets?