boundary condition in inducer

thousand · July 28, 2012, 04:03

hi
i'm trying to model a inducer in rated flow of pump
suction pressure is known but pressure in outlet of inducer and inlet to impller is unknown
i try with pressure inlet and pressure outlet(i guess a pressure) and compute the flow rate and compare it with nominal flow rate but i have not enough time to iterate with wide guess pressures.
Am I putting the right boundary condition at the outlet or inlet?
can you give me a better strategy?
tanks alot

eng_s_sadeghi · July 28, 2012, 07:34

This is not possible, you should know the outlet pressure. Also I think it is better to use mass flow inlet for better converges. I mean put the real mass flow in the inlet and the outlet pressure, after solving check if the inlet pressure is correct or know.

thousand · July 29, 2012, 17:32

thanks a lot
i try with increase 3m in head in inducer but flow rate was very far from my desire flow rate but range of pressure was very far from cavitation
i too simulate in free cavitation , with pressure inlet in inlet and mass flow rate in outlet increase in head is about 24m and is mistake beacuse maximum incrase head must be 5% total head (9 m).
there is a problem that inducer act as axial pump and his flow rate is independet from head
now this act for checking flow rate in various pressure or checking pressure in various flow rate is true?

July 28, 2012, 04:03	boundary condition in inducer	#1
thousand New Member khalil Join Date: Jul 2012 Posts: 21 Rep Power: 14	hi i'm trying to model a inducer in rated flow of pump suction pressure is known but pressure in outlet of inducer and inlet to impller is unknown i try with pressure inlet and pressure outlet(i guess a pressure) and compute the flow rate and compare it with nominal flow rate but i have not enough time to iterate with wide guess pressures. Am I putting the right boundary condition at the outlet or inlet? can you give me a better strategy? tanks alot

July 28, 2012, 07:34		#2
eng_s_sadeghi Member Join Date: Mar 2011 Posts: 64 Rep Power: 15	This is not possible, you should know the outlet pressure. Also I think it is better to use mass flow inlet for better converges. I mean put the real mass flow in the inlet and the outlet pressure, after solving check if the inlet pressure is correct or know. __________________ Saeed Sadeghi Ansys Fluent CFD Consultant

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July 29, 2012, 17:32		#3
thousand New Member khalil Join Date: Jul 2012 Posts: 21 Rep Power: 14	thanks a lot i try with increase 3m in head in inducer but flow rate was very far from my desire flow rate but range of pressure was very far from cavitation i too simulate in free cavitation , with pressure inlet in inlet and mass flow rate in outlet increase in head is about 24m and is mistake beacuse maximum incrase head must be 5% total head (9 m). there is a problem that inducer act as axial pump and his flow rate is independet from head now this act for checking flow rate in various pressure or checking pressure in various flow rate is true?