# Particle Injection Mass Flow Rate and Position

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 April 24, 2011, 14:26 Particle Injection Mass Flow Rate and Position #1 New Member   Leon Ong Join Date: Nov 2010 Posts: 7 Rep Power: 15 Hi community, 1) Does anyone know how to get the total mass flow rate in Particles injection. mass flow rate = density x area x velocity it look simple if consider only fluid flow in pipe. does particle mass flow need other formula or do i need to fin speed for the particles which i dont know how? I got details for pipe- density, area and fluid velocity, particles- density and diameter(sphere) and volume fraction of 0.073 2) How to inject particles at the bottom of the pipe. is it to select injection type as single and key in x,y,z value. cause my seems not able to converge. and what should the particle velocity be like zero or my fluid flow velocity? some one please help... plz

April 29, 2011, 05:04
#2
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ANIL
Join Date: Apr 2011
Posts: 3
Rep Power: 15
Quote:
 Originally Posted by leonozx Hi community, 1) Does anyone know how to get the total mass flow rate in Particles injection. mass flow rate = density x area x velocity it look simple if consider only fluid flow in pipe. does particle mass flow need other formula or do i need to fin speed for the particles which i dont know how? I got details for pipe- density, area and fluid velocity, particles- density and diameter(sphere) and volume fraction of 0.073 2) How to inject particles at the bottom of the pipe. is it to select injection type as single and key in x,y,z value. cause my seems not able to converge. and what should the particle velocity be like zero or my fluid flow velocity? some one please help... plz
Hi...
single line injection gives a single path of particles injected into the primary flow.
there are multiple options available as far as injection is considered. which option u choose depends on its relevance to the real time problem. as far as injecting the particles is concerned, u can specify the point of injection using the x,y,z(z if 3-D) co-ordinates.
The number of inputs vary between different injection methods.

 April 29, 2011, 09:19 #3 New Member   Leon Ong Join Date: Nov 2010 Posts: 7 Rep Power: 15 yeah i check le why it cant converge with my question 1. I am using DPM model the volume fraction had been ok in the system under 10 percent but whent the particle fall due to gravity effect and with a high loading it get too concentrated and cause solution not being able to converge. Alternative will be using Eulerian model with DDPM but it dun come with erosion whcih that is what i need to do in my disseatation dueing in 1 week time. and i dunno what to put into my report other than a fail simulation. thanks anyway

 March 9, 2018, 09:58 help #4 New Member   nirjhor Join Date: Feb 2015 Posts: 7 Rep Power: 11 I have noticed that for surface injection the number of particle does not change, with respect to the change of mass flow rate. I am just wondering, why is that. Since the mass of each particle is constant by the diameter and density, I thought increasing mass flow rate should increase the particle number. Can anyone please help me to clarify it?

 Tags dpm, dpm in fluent, fluent, mass flow rate, particle