×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# parameter estimation of heat energy balance by using lsqcurvefit

## parameter estimation of heat energy balance by using lsqcurvefit

(OP)
Hi,

I have the following problem and maybe someone can give me a clue how to solve it.
I have collected data (Temperature, Q_gen, Ambient temperature) of a heating process and now I want to estimate some parameters in order to solve the energy balance.
This is the energy balance:
internal Energy = Heat generated - Heat flux due to convection
m*cp*dT/dt = Q_dot_generated-Q_dot_convection
Q_dot_convection=1/R * (T-T_amb)
C=m*cp;
--> dT/dt=1/(C)*(Q_dot_generated - 1/R * (T-T_amb))

I wrote a function which looks basically like this:
function [T] = myfunc(Parameter, Data)
Q_dot_gen=Data(:,1);
T(1,1)=Data(1,2);
T_amb=Data(:,2);
C=Para(1);
R_T=Para(2);

for i=1:length(Data(:,1))
dT=1/(C)*(Q_dot_generated(i) - 1/R * (T(i)-T_amb(i)));
T(i+1)=T(i)+dT;
end

Then I pass everything to lsqcurvefit in order to solve it:
Parameter=lsqcurvefit(@myfunc, [10000, 0.5], Data, T_Process)

I got something but I am wondering if I do it right. I haven't much experience or knowledge about solving such proplems but I am happy to learn more about it.

If someone can share some knowledge, it would be great.

Regards,

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

#### Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a partâ€™s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!