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ehtesham.bokhari
Posts: 28
Registered: ‎03-06-2013
Accepted Solution

Heat Transfer Simulation Steady or Transient

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01-20-2014 11:19 PM

Hi,

I am trying to conduct this experiment. I have this setup (attached jpg).

I have a solar receiver that is getting a concentrated beam generating 16 w/mm2. it is a Aluminum duct wrapped with different layers of insulations on three sides and an air channel on the fourth side with cover of glass. ambient temperature is 25 'C

 

What I want to simulation is.

Putting a heat source on the botton of the Aluminum Duct. with body to body radiation and heat losses through the insulations and on the last layer exposed to air I want to add convection with air

 

on the botton side, I want to ad convection inside the air channel with Glass holding the radiations.

Please guide me how and what to set the boundry conditions and Nodal settings.

 

My (.fem) file is also attached. Please help me to get it work. It is not letting me to upload FEM file

 

To start with I dont mind transient of steady heat transfer. I just want to simulate it.

 

Regards

Ehtesham

Ehtesham Bokhari
PhD Student
Thermal and CFD Simulation Analysis
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Active Contributor
ehtesham.bokhari
Posts: 28
Registered: ‎03-06-2013

Re: Heat Transfer Simulation Steady or Transient

01-20-2014 11:44 PM in reply to: ehtesham.bokhari

It says

 

Warning: Material Model is not properly set
Error. Invalid or missing data

 

 **** FLUID FLOW CONVECTION IS NOT INCLUDED IN THIS MODEL.

 

Since, I have not there is no physical part in the inventor file for "AIR" How would I explain the Fluid Flow convection

Please suggest.

what am I missing.

 

Thanks

Ehtesham Bokhari
PhD Student
Thermal and CFD Simulation Analysis
Please use plain text.
Active Contributor
ehtesham.bokhari
Posts: 28
Registered: ‎03-06-2013

Re: Heat Transfer Simulation Steady or Transient

01-21-2014 12:32 AM in reply to: ehtesham.bokhari

I am doing this in Mechanical 2014 and this only has Thermal Simulation. I don't have Multiphysics

Ehtesham Bokhari
PhD Student
Thermal and CFD Simulation Analysis
Please use plain text.
Valued Mentor
AstroJohnPE
Posts: 510
Registered: ‎08-30-2012

Re: Heat Transfer Simulation Steady or Transient

01-21-2014 01:04 PM in reply to: ehtesham.bokhari

 

Hi Ehtesham,

 

The sentence about the fluid flow convection is just reporting that fluid flow results are not being used; in other words, that sentence is just for information. The problem is the warning (material model not set) and error (invalid data) although it is not entirely clear what data is missing.

 

I think the solution is to edit the material for each part, one by one. Eventually you will find a part (or maybe several parts, or maybe all parts) that either gives a warning that the material model is not set, or the material properties are missing required data (such as thermal conductivity for a steady state heat transfer, or density and specific heat for a transient analysis).

 

If the warning occurs, edit the Element Definition for the part and click OK. Then edit the material.

 

Good luck.

John Holtz, PE
Mechanical Engineer
Pittsburgh, PA

16 years experience with Simulation Mechanical
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Active Contributor
ehtesham.bokhari
Posts: 28
Registered: ‎03-06-2013

Re: Heat Transfer Simulation Steady or Transient

01-21-2014 10:14 PM in reply to: ehtesham.bokhari

 This is the warning message. how ever I am now trying to define appropriate/required data.

I will share my results 

 

Thanks 

 

 

Autodesk (R) Simulation Steady-State Heat Transfer
Version 2014.00.00.0513-W64/X64 22-Feb-2013
Copyright (c) 2013, Autodesk, Inc. All rights reserved.

**** Memory Dynamically Allocated = 6176396 KB
**** Steady-State Heat Transfer Analysis

----------------------------------------------------------------
DATE: JANUARY 22, 2014
TIME: 11:12 AM
Input Model: E:\Inventor Working Files\Receiver Simulation\Receiver Assembly ver1.0.ds_data\2\ds


PROGRAM VERSION: 201400000513
alg-win-x64.dll VERSION: 201400000513
algconfig-win-x64.dll VERSION: 201400000513
agsdb_ar-win-x64.dll VERSION: 201400000513
solvercallback-win-x64.dll VERSION: 201400000513
amgsolve.exe VERSION: 0360000000


Options executed are:
NOMIN
SUPSTR


processing ...

**** Model Unit System Settings:
--------------------------------------------
Unit System : Custom
Force : N
Length : mm
Time : s
Temperature (Absolute) : deg C (K)
Thermal Energy : J
Voltage : V
Current : A
Electrical Resistance : ohm
Mass : N*s^2/mm
--------------------------------------------

**** OPENING TEMPORARY FILES
NDYN = 10
**** BEGIN NODAL DATA INPUT
Node number= 7837
Equation number= 7837
**** END NODAL DATA INPUT
Warning: Material Model is not properly set
Error. Invalid or missing data

Ehtesham Bokhari
PhD Student
Thermal and CFD Simulation Analysis
Please use plain text.
Active Contributor
ehtesham.bokhari
Posts: 28
Registered: ‎03-06-2013

Re: Heat Transfer Simulation Steady or Transient

01-21-2014 10:47 PM in reply to: ehtesham.bokhari

I am making it furher simpler to at least start my simulation working.

I will start with steady heat transfer

 

My scenario is a heat source in the middle insulation at its three sides.

on the fourth side there is Air  gap

after the air gap there is a glass that is trapping infrared. 

 

Please see the attached picture for the cross section of my scenario. My scenario is 12 foot long this is cross section. so I will be doing it on 3D simulation

 

Please suggest me. what element type should be define   to the heat source (Al metal square rod)

what element should be define to insulation?

what element type should I define the 5mm transparent glass 

 

how should I define air gap, there is no part.

 

On all the sides ourside and inside glass where air is touching, I am defining Convection 

 

Please see the attached image and suggest what settings to keep in order to make this simulation work.

 

Ehtesham Bokhari
PhD Student
Thermal and CFD Simulation Analysis
Please use plain text.
Active Contributor
ehtesham.bokhari
Posts: 28
Registered: ‎03-06-2013

Re: Heat Transfer Simulation Steady or Transient

01-23-2014 01:27 AM in reply to: ehtesham.bokhari

 

attached is my result.

 

Can I do a Heat flow  with Convection and radiation at the same time on the same setup ?

 

Ehtesham Bokhari
PhD Student
Thermal and CFD Simulation Analysis
Please use plain text.
Valued Mentor
AstroJohnPE
Posts: 510
Registered: ‎08-30-2012

Re: Heat Transfer Simulation Steady or Transient

01-23-2014 08:34 AM in reply to: ehtesham.bokhari

The answer is yes.

 

But how do you intend to account for the effects that occur by the air trapped inside: conduction through the air, and currents transporting heat due to temperature differences (buoyancy)? The "convection" that you apply to the model will add or remove heat, but you cannot apply that amount of heat to another part of the model. In other words, the heat coming off of the aluminum that heats the air in reality is then transported to the sides and the glass and acts like a heat source to those components.

 

You probably should use Autodesk Simulation CFD: it can handle the air as a fluid and the other parts as a solid, etc.

 

In either case, you probably want to include the air in the model.

John Holtz, PE
Mechanical Engineer
Pittsburgh, PA

16 years experience with Simulation Mechanical
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Active Contributor
ehtesham.bokhari
Posts: 28
Registered: ‎03-06-2013

Re: Heat Transfer Simulation Steady or Transient

02-06-2014 09:37 PM in reply to: AstroJohnPE

yes. I will try it with CFD then.

But for now, I am doing different simulations of

Convections

Conduction

Radiations

seperately 

 

I will ask you when i am stuck any where

Ehtesham Bokhari
PhD Student
Thermal and CFD Simulation Analysis
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Active Contributor
ehtesham.bokhari
Posts: 28
Registered: ‎03-06-2013

Re: Heat Transfer Simulation Steady or Transient

02-07-2014 12:19 AM in reply to: ehtesham.bokhari

   In Body to body radiation i am getting this error

 

Error: No enabled surfaces in enclosure [2]!

 

I have mistakenly added multiple enclosures, and now I dont know from where to remove the extra enclosures

Ehtesham Bokhari
PhD Student
Thermal and CFD Simulation Analysis
Please use plain text.