Thermodynamics DiscussionsLatest discussions happening in the Thermodynamics category
https://studentcommunity.ansys.com
ANSYS for thermodynamic study<p><span style="color: #222222; font-family: 'Open Sans', 'Helvetica Neue', Helvetica, Arial, sans-serif;">Can we study thermodynamic properties of fluid and the work outputs in ANSYS. I'm working on a thermodynamics course project in which we generate Convection Currents that are going to drive a turbine (or propeller/airfoils). I want to study the thermodynamics properties, TS and PV diagrams and work outputs. It's very difficult to fabricate an apparatus to carry out the experiment. Therefore, I'm going for ANSYS (if it is applicable to the stated problem).</span></p>2018-05-26T05:05:10.9400000
https://studentcommunity.ansys.com/thread/ansys-for-thermodynamic-study/
Transient thermal analysis - Thermal interface<p>Hello,</p>
<p>I am trying to simulate the temperature effect of two bonded bodies, each at different temperatures. Body 1 is at 20 degrees Celsius and Body 2 is at 100 degrees Celsius. Body 1 is the cavity with a hole in the middle where body 2 is assembled and bonded. I run the simulation for 480 seconds. The heat in the model is transferred by conduction. Convection is applied at the top surfaces of both bodies and the boundaries of body 1 that contains body 2. I have experimentally run also this arrangement, so I have points to validate the model.</p>
<p>The problem that I have with the simulation results is that the temperature in the boundary increases very rapidly and this does not correspond to the reality. I have attached an example.</p>
<p>Could you please advise?</p>
<p>Many thanks.</p>2018-01-16T19:51:57.4270000
https://studentcommunity.ansys.com/thread/transient-thermal-analysis-thermal-interface/
Time dependent Variable Boundary Contidion<p>Hello,</p>
<p>how to use time dependent variable boundary conditions in Transient Thermal Analysis?</p>2018-05-15T22:06:24.8400000
https://studentcommunity.ansys.com/thread/variable-boundary-contidion/
I C ENGINES<p>CAN ANY ONE HELP ME TO FIND A GEOMETRY FILE OF IC ENGINE FOR ANA ANALYSIS JUST TO START LEARN HOW TO USE IC ENGINES MODULE?</p>2018-05-17T15:00:27.9770000
https://studentcommunity.ansys.com/thread/i-c-engines/
how to use ansys icepak together with MALAB?<p>it is gald to find this place to ask for help for my study. when I read the papers about the thermal analysis, some papers use the icepak together with matlab,which make me puzzle. Since that I do not how to use matlab in the icepak. It is sad that I can not find any materials about the ways to use matlab with icepak. so can somebody help me? and give me some tutorials or videos.<img src="/content/uploads/75df4bb6-de56-4e4c-aa18-a8da00a79665/3740405e-f1a3-435d-8011-a8da00e88e8f_qq截图20180508220620.jpg?width=690&upscale=false" alt=""></p>2018-05-08T14:07:23.6000000
https://studentcommunity.ansys.com/thread/how-to-use-ansys-icepak-together-with-malab/
AM extension ACTI really need the AM extension (.wbex) for additive manufacturing for ANSYS 19 to use in my graduation project. Any help?2018-04-19T07:55:39.2400000
https://studentcommunity.ansys.com/thread/am-extension-act/
Thermal expansion of a fluid<p>Hi,</p>
<p>I am new to ANSYS R19, and I want to see the thermal expansion of a fluid in ANSYS.</p>
<p>I have a table of density of the fluid against my temperature. How can I do it ?</p>
<p>I can work it around by getting the average temperature of my body and export to excel and get the density for each step and get a result.</p>
<p>But I don't know if this method is okay because it's the average temp how can i get temperature of each units and integrate it to get my volume.</p>
<p>Thanks.</p>2018-04-17T09:59:41.5970000
https://studentcommunity.ansys.com/thread/thermal-expansion-of-a-fluid/
Error during transient thermal and static structural analysis<p>I am getting the following error time and again during a transient thermal analysis with material properties changing with temperature, followed by a static structural analysis. Can someone help me with this?</p>
<p>"The reference temperature for the thermal expansion coefficient differs from the reference temperature of one or more bodies. The data will be adjusted to have a zero thermal strain at the reference temperature of each body. If the number of temperature points is sparse this could cause invalid values to be used for calculations. The recommendation is to have the same reference temperature on the bodies as the thermal expansion coefficient's reference temperature in Engineering Data or a dense number of temperature points."</p>
<p> </p>2018-03-27T17:30:43.0000000
https://studentcommunity.ansys.com/thread/error-during-transient-thermal-and-static-structural-analysis/
Transient Thermal Analysis of geometrically predeformed structure<p class="MsoNormal"><span lang="EN-US"><a name="_GoBack"></a></span></p>
<p><span lang="EN-US">Hey,</span><br><br><span lang="EN-US">with ANSYS Workbench 17.2, I am trying to simulate the behavior of a concrete filled steel tube (CFST) column under constant axial compression while being heated due to fire.</span><br><br><span lang="EN-US">The column consists of a steel tube filled with a concrete core and shows an initial imperfection (see picture A) implemented via Eigenvalue Buckling Analysis and APDL-code. The interface between both parts, steel tube and concrete core, is set to frictionless (might be changed to frictional later on).</span><br><br><span lang="EN-US">Now my problem is that the transient thermal analysis of this predeformed column delivers implausible, unsteady temperature fields (see picture B). I found out, that by setting the contact between steel tube and concrete core to Bonded the results are much more plausible (see picture C) but due to a mechanical loading, which will be implemented within a Static Mechanical Analysis later on, this does not represent reality well. I assumed that while using frictionless contact, there must be a small gap between the steel tube and the concrete core which results in this unsteadiness of the temperature field. I tried following settings which didn’t lead to better results:</span><br><br><span lang="EN-US">- Using default materials instead of self-defined ones</span><br><br><span lang="EN-US">- Refining the mesh</span><br><br><span lang="EN-US"><span>-<span style="font-family: 'Times New Roman'; font-size: xx-small;"> </span></span></span><span lang="EN-US">Manual Thermal Conductance Value of 1e-4 W/mm²</span><br><br><span lang="EN-US"><span>-<span style="font-family: 'Times New Roman'; font-size: xx-small;"> </span></span></span><span lang="EN-US">Interface Treatment = Adjust to Touch</span><br><br><span lang="EN-US"><span>-<span style="font-family: 'Times New Roman'; font-size: xx-small;"> </span></span></span><span lang="EN-US">Pinball Radius = 3000mm (surrounds whole model)</span><br><br><span lang="EN-US">Is there anyone who has an idea on how to solve this problem?</span><br><br><img src="/content/uploads/ddb1ac91-1c0d-48fa-8d3e-a8b100f63006/c324fbae-4656-40ce-a0da-a8ba00c9f1d2_bild1.jpg?width=690&upscale=false" alt=""><br><span lang="EN-US">Thanks a lot for your help.<a name="_GoBack"></a></span></p>
<p><span lang="EN-US"> </span></p>2018-04-06T12:17:00.7500000
https://studentcommunity.ansys.com/thread/transient-thermal-analysis-of-geometrically-predeformed-structure/
How 2 calculate volume after element death?<p>Hii there!! I am working on WEDM simulation and ELEMENT DEATH. I applied heat flux and allowed to kill the elements which are above a certain temperature. But I can' t calculate the amount of volume disappear after element death. I am usung MECHANICAL APDL. ANY SUGGESTIONS PLEASE!!! Thank You</p>2018-04-06T08:33:37.8970000
https://studentcommunity.ansys.com/thread/how-to-calculate-volume-after-element-death/
Error in Multi-domain Steady-state simulation<p>Hello, my name is Cahya. I am new in using ANSYS Fluent.</p>
<p>I have a problem in simulating my case. The case is a heat transfer between <strong>hot fluid inside a pipe (water-liquid)</strong> and a <strong>cold ambient air (air)</strong>. It seems to be a simple case but until now, I can not simulate it.</p>
<p>I ran it in steady state and activate the gravity, energy, and viscous model. There is an inlet boundary for hot fluid pipe and ambient air, I put different velocity and temperature for each boundary. At first try, it gave me error "floating point". Then I tried changing the solver method. It still gave me the same result.</p>
<p>Eventually, I changed the domain of ambient air from <strong>air to water-liquid. </strong>Surprisingly the simulation worked. I tried changing the domain of hot fluid from <strong>water-liquid</strong> to <strong>air</strong>. Also the simulation worked with this setup. I concluded that the simulation worked when the domain are the same.</p>
<p>Then I did several research to make the simulation work. The simulation of multi-domain worked when:</p>
<ul>
<li><strong>Turn off</strong> the gravity model</li>
<li>use <strong>coupled</strong> solution method, but not converge</li>
<li>both inlet boundary have the <strong>same temperature</strong></li>
</ul>
<p>I need help from you all.</p>
<p>Thank you</p>2018-03-28T09:34:11.1170000
https://studentcommunity.ansys.com/thread/error-in-multi-domain-steady-state-simulation/
Change absorptivity of the material<p>Good afternoon,</p>
<p>My name is Ricardo Gomes and I'm trying to calculate and simulate the temperature of an antenna in space. The antenna is not a gray-diffuse body, this is emission and absorptivity are different (lets assume epsilon = 0.9 and alpha = 0.8).</p>
<p>ANSYS doc. says that: "<em>Radiation exchange between surfaces is restricted to gray-diffuse surfaces. Gray implies that emissivity and absorptivity of the surface do not depend on wavelength (either can depend on temperature). Diffuse signifies that emissivity and absorptivity do not depend on direction. For a gray-diffuse surface, emissivity = absorptivity; and emissivity + reflectivity = 1. Note that a black body surface has a unit emissivity."</em></p>
<p>Does this mean that it is not possible to have different values for the emissivity and absorptivity?</p>
<p>Should I compute this values based on hand calculation using the total flux that is absorbed by the material. This is, I have a thermal flux due to solar radiation that is 1400 W/m^2. If the material as a absorptivity of 0.6 I must only assume and heat flux of 1400*0.6 = 840 W/m^2.</p>
<p>Thank you in advance.</p>2018-03-13T15:40:02.0470000
https://studentcommunity.ansys.com/thread/change-absorptivity-of-the-material/
Problems with Solver using Steady State Thermal<p>Hi</p>
<p> </p>
<p>I am trying to complete the Ansys EDX course offered by Cornell University and the solver solution does not seem to generate the mathematical model. I have done everything as per the boundary conditions and mesh requiements but cannot get the solver to generate the mathematical solution</p>
<p> </p>
<p>Please send me your ideas, since I have no idea where is my error?</p>
<p> </p>
<p>Is it a processor or settings problem?</p>
<p> </p>
<p>I have a HP Spectrex360 4K with 16GB RAM quad core</p>
<p> </p>
<p>Many thanks</p>
<p>Niresh</p>2017-12-04T19:00:52.1800000
https://studentcommunity.ansys.com/thread/problems-with-solver-using-steady-state-thermal/