Heat transfer through pipe wall

billue123 · June 4, 2013, 11:51

I am designing a gas water heater. i have modelled and meshed the whole structure. unfortunately the flue gases which are at a temprature of 750K do not seem to heat up the water through the wall. the temperature of the water remain at 303K at 2.5sec to 1min. Please help me in this regard kindly. what options in the wall must i select "on" so that heat is transfered through it to the water
thanks

delaneyluke · June 4, 2013, 15:58

Your walls (between the flue gas and pipe and water) should be defined as coupled walls

Regards
Luke

billue123 · June 4, 2013, 16:41

how can i define it as couple wall? in the fluent on the option of wall comes?

delaneyluke · June 4, 2013, 17:59

Yes it is an option in wall BC screen, i think under the Temperature tab

Regards
Luke

billue123 · June 5, 2013, 04:15

unfortunately i can not find such option. the options available to me are as follow in the picture shown.kindly please help

June 4, 2013, 11:51	Heat transfer through pipe wall	#1
billue123 New Member sheikh Join Date: Apr 2013 Posts: 16 Rep Power: 13	I am designing a gas water heater. i have modelled and meshed the whole structure. unfortunately the flue gases which are at a temprature of 750K do not seem to heat up the water through the wall. the temperature of the water remain at 303K at 2.5sec to 1min. Please help me in this regard kindly. what options in the wall must i select "on" so that heat is transfered through it to the water thanks

June 4, 2013, 15:58		#2
delaneyluke Senior Member Join Date: Mar 2009 Location: Indiana, US Posts: 186 Rep Power: 17	Your walls (between the flue gas and pipe and water) should be defined as coupled walls Regards Luke billue123 likes this.

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June 4, 2013, 16:41		#3
billue123 New Member sheikh Join Date: Apr 2013 Posts: 16 Rep Power: 13	how can i define it as couple wall? in the fluent on the option of wall comes?

June 4, 2013, 17:59		#4
delaneyluke Senior Member Join Date: Mar 2009 Location: Indiana, US Posts: 186 Rep Power: 17	Yes it is an option in wall BC screen, i think under the Temperature tab Regards Luke