how to write derivation of source(x,y,z)?

February 27, 2006, 20:41

hi.i would like linearize my energy source(x,y,z)in UDF,but i don't know who should be its argument in 3D.please help me. thanks!

February 28, 2006, 04:28

maybe you got something wrong. linearizing a source term requires the derivation with respect to the dependent variable of the governing equation (enthalpy or temperature in your case) and not in terms of spatial coordinates Markus

February 28, 2006, 07:34

focused laser energy is Gaussian distribution in 3D,so 3D energy source term in UDF is necessary in order to simulate a melting process.

February 28, 2006, 08:00

The source term may be a divergence term in 3D space but Markus is correct about linearising the source term. It must be done with respect to the dependant variable of the particular transport equation.

Patankar has a good book with information about linearising source terms. "Numerical heat transfer and fluid flow" 1980

February 27, 2006, 20:41	how to write derivation of source(x,y,z)?	#1
wanghong Guest Posts: n/a	hi.i would like linearize my energy source(x,y,z)in UDF,but i don't know who should be its argument in 3D.please help me. thanks!

February 28, 2006, 04:28	Re: how to write derivation of source(x,y,z)?	#2
Markus Guest Posts: n/a	maybe you got something wrong. linearizing a source term requires the derivation with respect to the dependent variable of the governing equation (enthalpy or temperature in your case) and not in terms of spatial coordinates Markus

February 28, 2006, 07:34	Re: how to write derivation of source(x,y,z)?	#3
wanghong Guest Posts: n/a	focused laser energy is Gaussian distribution in 3D,so 3D energy source term in UDF is necessary in order to simulate a melting process.

February 28, 2006, 08:00	Re: how to write derivation of source(x,y,z)?	#4
Aidan Guest Posts: n/a	The source term may be a divergence term in 3D space but Markus is correct about linearising the source term. It must be done with respect to the dependant variable of the particular transport equation. Patankar has a good book with information about linearising source terms. "Numerical heat transfer and fluid flow" 1980

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