Latent Heat Cannot be Less than zero

cvnaditya · June 29, 2022, 03:26

Hi all, I'm practicing multiphase analysis in fluent,

my problem involves air, R134a liquid & R134a vapour I have assign the properties and while going through initialization i have noticed this error.

Compute Node ID: 3
From-phase Domain ID: 1
To-phase Domain ID: 2
Cell Number: 0
Latent Heat: -294579

ERROR: Latent heat cannot be less than zero!

could you please help me to understand and resolve this error

sree kumaran · November 7, 2022, 04:20

have u found out how to solve the error

cvnaditya · November 12, 2022, 11:25

yes, it is solved

sree kumaran · November 12, 2022, 11:44

Can u share how did u solve it please

cvnaditya · November 12, 2022, 11:54

sure, in ansys it is suggested to consider latent heat for refrigerant in liquid material as zero

in ansys fluent, latent heat is calculated from standard state enthalpy of phase participating in mass exchange
only enthalpy difference matters

hvl(enthalpy total or vapour & liquid at ref temperature)= hv(vapour enthalpy)-hl(liquid enthalpy) at reference temperatures

so it is better to consider liquid enthalpy as zero

cvnaditya · November 12, 2022, 11:55

it is better to use

Tref= Tsat
hv, Tsat= hvl,Tsat

sree kumaran · November 12, 2022, 12:08

So in a evaporation condensation cycle should i put sse of water zero and air as it is

mhmmad_ibraham · March 27, 2023, 11:34

Quote:

Originally Posted by cvnaditya

it is better to use

Tref= Tsat
hv, Tsat= hvl,Tsat

Hello
where can I find Tref and Tsat in fluent?
Thank you

June 29, 2022, 03:26	Latent Heat Cannot be Less than zero	#1
cvnaditya New Member Hellboy Join Date: Apr 2018 Posts: 5 Rep Power: 8	Hi all, I'm practicing multiphase analysis in fluent, my problem involves air, R134a liquid & R134a vapour I have assign the properties and while going through initialization i have noticed this error. Compute Node ID: 3 From-phase Domain ID: 1 To-phase Domain ID: 2 Cell Number: 0 Latent Heat: -294579 ERROR: Latent heat cannot be less than zero! could you please help me to understand and resolve this error

November 7, 2022, 04:20		#2
sree kumaran New Member Sree Kumaran T Join Date: Nov 2022 Posts: 4 Rep Power: 4	have u found out how to solve the error cvnaditya likes this.

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November 12, 2022, 11:25		#3
cvnaditya New Member Hellboy Join Date: Apr 2018 Posts: 5 Rep Power: 8	yes, it is solved

November 12, 2022, 11:44		#4
sree kumaran New Member Sree Kumaran T Join Date: Nov 2022 Posts: 4 Rep Power: 4	Can u share how did u solve it please

November 12, 2022, 11:54		#5
cvnaditya New Member Hellboy Join Date: Apr 2018 Posts: 5 Rep Power: 8	sure, in ansys it is suggested to consider latent heat for refrigerant in liquid material as zero in ansys fluent, latent heat is calculated from standard state enthalpy of phase participating in mass exchange only enthalpy difference matters hvl(enthalpy total or vapour & liquid at ref temperature)= hv(vapour enthalpy)-hl(liquid enthalpy) at reference temperatures so it is better to consider liquid enthalpy as zero

November 12, 2022, 11:55		#6
cvnaditya New Member Hellboy Join Date: Apr 2018 Posts: 5 Rep Power: 8	it is better to use Tref= Tsat hv, Tsat= hvl,Tsat

November 12, 2022, 12:08		#7
sree kumaran New Member Sree Kumaran T Join Date: Nov 2022 Posts: 4 Rep Power: 4	So in a evaporation condensation cycle should i put sse of water zero and air as it is