Particle Pathline: User Manual Doubt

Pravaah · April 25, 2019, 06:37

This is regarding particle pathline calculation procedure mentioned in Tecplot's user manual. https://www.tecplot.com/documentation/

So my question is regarding the procedure adopted there:
the first step is to generate streamlines and then mention values for velocity components, mass, radius and drag coefficient.

Why pressure values are not being taken as input?
Even in the documentation, there is no mention of contribution, in particle's acceleration, by the pressure gradient.

davetaflin · April 26, 2019, 21:25

The density of the particles is assumed to be much larger than the density of the fluid, making pressure forces unimportant. See FLUENT's explanation of this here: https://www.sharcnet.ca/Software/Ans...le_motion.html

Pravaah · April 28, 2019, 10:41

Many thanks for reply

I had one counter question:

What you are saying is true for Fluent.

What about Tecplot? because there is no mention of any such assumption.

Why do they calculate stramlines first? Is it for inital guess of path only?
I was thinking if it gets density and velocities then it can easily calculate pressure gradients for those terms.

April 25, 2019, 06:37	Particle Pathline: Missing Pressure Gradient Term	#1
Pravaah New Member Join Date: May 2015 Posts: 5 Rep Power: 11	This is regarding particle pathline calculation procedure mentioned in Tecplot's user manual. https://www.tecplot.com/documentation/ So my question is regarding the procedure adopted there: the first step is to generate streamlines and then mention values for velocity components, mass, radius and drag coefficient. Why pressure values are not being taken as input? Even in the documentation, there is no mention of contribution, in particle's acceleration, by the pressure gradient. Last edited by Pravaah; April 26, 2019 at 07:48.

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April 26, 2019, 21:25		#2
davetaflin New Member Dave Taflin Join Date: Nov 2017 Posts: 12 Rep Power: 9	The density of the particles is assumed to be much larger than the density of the fluid, making pressure forces unimportant. See FLUENT's explanation of this here: https://www.sharcnet.ca/Software/Ans...le_motion.html

April 28, 2019, 10:41		#3
Pravaah New Member Join Date: May 2015 Posts: 5 Rep Power: 11	Many thanks for reply I had one counter question: What you are saying is true for Fluent. What about Tecplot? because there is no mention of any such assumption. Why do they calculate stramlines first? Is it for inital guess of path only? I was thinking if it gets density and velocities then it can easily calculate pressure gradients for those terms.