UDF for non uniform heat flux around cylinder

binjoes · December 28, 2017, 23:47

Hi,
I am currently working on analysis of Parabolic Trough Collector. I have an an equation for heat flux with respect to angle. Can anyone help me regarding this problem.

LCR = b3*f^3+b2*f^2+b1*f+b0

f- angle in 0-360

KAA · April 20, 2018, 02:52

Dear binjo,
I am also working on writing UDF codes for an PTC absorber tube i.e., UDF for implementing non uniform heat flux around the absorber section. Can u please help me in it.

binjoes · April 22, 2018, 01:27

Mr. Arshad, somehow i wrote the program for non uniform heat flux by myself. How good are you in c programming? Do you have any profile with you to convert it into boundary condition like Concentration ratio profile or Heat flux profile? Reply asap. I can guide you.

KAA · April 22, 2018, 12:12

I'm some 40% good with C language. But exactly I do not have any Heat Flux profile with me. Arbitrarily I wrote a program, but it does not hold good.

binjoes · April 22, 2018, 12:43

Ok, Find(From journals) or prepare a profile (using a software like Soltrace, more authentic method)

Convert the profile into set of curves with 3rd degree polynomeal equation using excel or any other software.

Write the code for polynomial equation.

AlexanderZ · April 22, 2018, 21:36

If you want to apply heat flux as a boundary condition, than go to manual Ansys Fluent Customization Manual and check DEFINE_PROFILE macro

best regards

KAA · September 9, 2018, 14:33

y = -9E-07x5 + 0.001x4 - 0.393x3 + 64.07x2 - 3725.x + 53733
How to start with the heat flux UDF for this equation around the absorber tube. kindly help me with it.

gearboy · September 10, 2018, 22:03

Quote:

Originally Posted by binjoes

Hi,
I am currently working on analysis of Parabolic Trough Collector. I have an an equation for heat flux with respect to angle. Can anyone help me regarding this problem.

LCR = b3*f^3+b2*f^2+b1*f+b0

f- angle in 0-360

Is it a boundary condition? if yes, use DEFINE_PROFILE to define it. If no, you should use DEFINE_SOURCE to specify the heat source for the first cell layer.

nima.shirani · June 14, 2019, 05:54

Quote:

Originally Posted by binjoes

Hi,
I am currently working on analysis of Parabolic Trough Collector. I have an an equation for heat flux with respect to angle. Can anyone help me regarding this problem.

LCR = b3*f^3+b2*f^2+b1*f+b0

f- angle in 0-360

hi
could you plz link your valid paper to me ... i have same problem and need to find a non uniform eq for heat flux

Nourhan Bahgat · October 19, 2019, 17:36

please how write udf code for heat flux change with angle as a BC in fluent.

Nourhan Bahgat · November 11, 2019, 05:09

Quote:

Originally Posted by binjoes

Mr. Arshad, somehow i wrote the program for non uniform heat flux by myself. How good are you in c programming? Do you have any profile with you to convert it into boundary condition like Concentration ratio profile or Heat flux profile? Reply asap. I can guide you.

please , can you guide me to write code in c for this graph Screenshot (37).jpg

dhiraj kumar · February 22, 2022, 03:26

hello everyone. I have a solar receiver in which at outer surface of the receiver i have to apply non-uniform heat flux [cosine profile - q(θ) = qnet ·
cos θ(−90 ≤ θ ≤ 90)] with radiation and convection losses to ambient. can anyone give me the idea for writing the UDF for this condition. thanks !

December 28, 2017, 23:47	UDF for non uniform heat flux around cylinder	#1
binjoes New Member Binjo Geo Join Date: Dec 2017 Posts: 4 Rep Power: 8	Hi, I am currently working on analysis of Parabolic Trough Collector. I have an an equation for heat flux with respect to angle. Can anyone help me regarding this problem. *LCR = b3f^3+b2f^2+b1f+b0** f- angle in 0-360

April 20, 2018, 02:52	CFD modelling with UDF	#2
KAA New Member arshad ahmed Join Date: Apr 2018 Posts: 4 Rep Power: 8	Dear binjo, I am also working on writing UDF codes for an PTC absorber tube i.e., UDF for implementing non uniform heat flux around the absorber section. Can u please help me in it.

April 22, 2018, 12:12	Dear Mr. Binjo,	#4
KAA New Member arshad ahmed Join Date: Apr 2018 Posts: 4 Rep Power: 8	I'm some 40% good with C language. But exactly I do not have any Heat Flux profile with me. Arbitrarily I wrote a program, but it does not hold good.

April 22, 2018, 21:36		#6
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	If you want to apply heat flux as a boundary condition, than go to manual Ansys Fluent Customization Manual and check DEFINE_PROFILE macro best regards KAA likes this.

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April 22, 2018, 01:27		#3
binjoes New Member Binjo Geo Join Date: Dec 2017 Posts: 4 Rep Power: 8	Mr. Arshad, somehow i wrote the program for non uniform heat flux by myself. How good are you in c programming? Do you have any profile with you to convert it into boundary condition like Concentration ratio profile or Heat flux profile? Reply asap. I can guide you.

April 22, 2018, 12:43		#5
binjoes New Member Binjo Geo Join Date: Dec 2017 Posts: 4 Rep Power: 8	Ok, Find(From journals) or prepare a profile (using a software like Soltrace, more authentic method) Convert the profile into set of curves with 3rd degree polynomeal equation using excel or any other software. Write the code for polynomial equation.

September 9, 2018, 14:33		#7
KAA New Member arshad ahmed Join Date: Apr 2018 Posts: 4 Rep Power: 8	y = -9E-07x5 + 0.001x4 - 0.393x3 + 64.07x2 - 3725.x + 53733 How to start with the heat flux UDF for this equation around the absorber tube. kindly help me with it.

October 19, 2019, 17:36		#10
Nourhan Bahgat New Member Nourhan Bahgat Join Date: Aug 2019 Posts: 13 Rep Power: 7	please how write udf code for heat flux change with angle as a BC in fluent.

February 22, 2022, 03:26		#12
dhiraj kumar New Member dhiraj Join Date: Nov 2021 Posts: 6 Rep Power: 5	hello everyone. I have a solar receiver in which at outer surface of the receiver i have to apply non-uniform heat flux [cosine profile - q(θ) = qnet · cos θ(−90 ≤ θ ≤ 90)] with radiation and convection losses to ambient. can anyone give me the idea for writing the UDF for this condition. thanks !