Granular model to simulate sand bed

kharnabnew · October 1, 2015, 01:20

Hi all,
I am simulating bed erosion using the Granular Eulerian model. The bed is patched, initially, within a pipe. Then, a turbulent flow entrains the sand particles. The objective is to replicate the bed erosion with time and to quantify the entrainment rate. I am comparing my simulation results to experiments I did myself and the behavior of the bed is different between CFD and exp. In CFD the bed spreads and its leading edge moves in the opposite direction of the flow close to the wall towards the inlet of the pipe which is inconsistent with the experiments. In the experiments the particles are all entrained in the flow direction towards the pipe outlet and the shape of the bed changes with time in different ways depending on the flow speed.
I believe it is something related to the viscosity or the properties of the secondary phase considered as a fluid in the Eulerian model and some tuning has to be done to replicate the behavior of a solid phase.
Can anyone explain what is the causes of such an issue in the Granular model? I will appreciate if someone shares his similar experience with me.
Thank you in advance

devesh.baghel · October 1, 2015, 06:56

Hi,

What are the BC you are using in your simulation....?

Regards

kharnabnew · October 1, 2015, 06:59

Velocity profile at the inlet of the pipe, outflow and no slip at walls. I also tried few values of specularity coefficient at walls.

October 1, 2015, 01:20	Granular model to simulate sand bed	#1
kharnabnew Member khar nab Join Date: Sep 2009 Posts: 34 Rep Power: 16	Hi all, I am simulating bed erosion using the Granular Eulerian model. The bed is patched, initially, within a pipe. Then, a turbulent flow entrains the sand particles. The objective is to replicate the bed erosion with time and to quantify the entrainment rate. I am comparing my simulation results to experiments I did myself and the behavior of the bed is different between CFD and exp. In CFD the bed spreads and its leading edge moves in the opposite direction of the flow close to the wall towards the inlet of the pipe which is inconsistent with the experiments. In the experiments the particles are all entrained in the flow direction towards the pipe outlet and the shape of the bed changes with time in different ways depending on the flow speed. I believe it is something related to the viscosity or the properties of the secondary phase considered as a fluid in the Eulerian model and some tuning has to be done to replicate the behavior of a solid phase. Can anyone explain what is the causes of such an issue in the Granular model? I will appreciate if someone shares his similar experience with me. Thank you in advance

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Euler Granular Model	Sashankh	FLUENT	1	January 29, 2017 12:41
Is it possible to simulate tank filling process in 2D (VOF Model)?	Blue	FLUENT	0	November 30, 2013 12:47
Simulate Coal Gasification with Non-Premixed Combustion Model	nurul efha	FLUENT	0	November 2, 2012 00:51
Granular model in Fluent Vs CFX	US	FLUENT	0	August 15, 2005 19:41
eulerain multiphase model for granular flow	satyam	FLUENT	0	August 4, 2005 18:03

October 1, 2015, 06:56		#2
devesh.baghel Member Devesh Baghel Join Date: Mar 2009 Posts: 84 Rep Power: 17	Hi, What are the BC you are using in your simulation....? Regards

October 1, 2015, 06:59		#3
kharnabnew Member khar nab Join Date: Sep 2009 Posts: 34 Rep Power: 16	Velocity profile at the inlet of the pipe, outflow and no slip at walls. I also tried few values of specularity coefficient at walls.