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  1. Acupro, i considered that, unfortunately, I forgot to mention that I also have temperature dependent data at several pressures. The ultimate goal was to create a user defined functions to account for the pressure. Ideally, I would like to use a user defined function that mimics a piecewise linear relationship, but uses different parameters for different pressures.
  2. All, I am trying to write a user defined function for Cp and enthalpy, but I found the documentation a little confusing. the enthalpy and Cp data i have is obtained from RefProp (NIST Reference Fluid Properties database) and attached to this post. from heat transfer/Thermodynamics equations: deltaH = Cp(T) * deltaT. But, Acusolve's documentation states that for a user defined function, both enthalpy and Cp must be provided: "acuSolve has no way of calculating the specific heat from the enthalpy, so both must be supplied by the user defined function" - from the Command Reference Manual. from the file I attached, a Cp and H are provided at a given temperature. However, I do not know if I should just provide those values to Acusolve, or is there a relationship that i'm missing? I want to stay away from the phase change and address the latent heat issue later. For now, i want to focus on either all liquid or vapor analysis. I come from a structural background, and my CFD skills are a little rusty. So far, I've been able to write user defined functions for density, viscosity, and conductivity, which are working. I have also been staying away from the phase change temperature, so the problems i've been running stay in the liquid phase. ultimately, I would like to address the phase change, but that is another problem for another day. hopefully i was clear enough for somebody to help me. methaneEnthalpyCpData.txt
  3. acupro, thank you very much for the help. Unfortunately, a comma-separated list did not work on windows, and I could not find any documentation on how to provide the list on the local Acusim.cnf file ( C:\Program Files\Altair\2017-edu\acusolve\win64\script\Acusim.cnf ). Keep in mind that i have very basic computer skills, and acuMakeDll -h did not provide much assistance. I was able to compile using only acuMakeDll (which you mentioned will compile any .c file in the directory), which meant i had to move other user-defined functions that i'm still working on to a different directory, while i compile the user defined functions i listed previously. if you have time, i would appreciate any help you can provide on how to provide a list to the .cnf file. Thank you
  4. ydigit, thank you very much, I will take a look at those workshops
  5. i was able to compile user-defined functions for density and viscosity. I compile them individually and when i run my analysis, it gives me the following error: *** ERROR: Unable to locate function <methaneViscosity> in libraries <./libusr.dll,~/libusr.dll> where methaneViscosity is the first user defined function that i compile. to clarify, i submit the following two commands: acuMakeDll -src methaneViscosity.c and acuMakeDll -src methaneDensity.c . Since i submit the commands individually, each creates a libusr.lib and object libusr.exp . This means that the libusr.lib/libusr.exp created by the first acuMakeDll commands is overwritten by the second acuMakeDll. I believe this is the reason why the error occurs.
  6. I want to test some user defined functions in Acusolve, but because I'm running in a laptop, i would like to create a simple model to see how my functions react. does acusolve have 2D capabilities? if so, can you point me to the right tutorial/validation model that shows this? thank you
  7. acupro, thank you very much, that did it!!! I have a followup question regarding compiling C files for a Acusolve user defined function. if you take a look at the attached doc on my original question (usrMyDensity.c), you'll see that it is a very simple linear equation. I kept it simple so I could get familiar with compiling user defined functions and calling them in the input file. However, I now want to create a user defined function that interpolates the density between temperature and pressure. I wrote a very crude C++ program in Visual Studio to open a .txt file, find pressure and temperatures, and interpolate the density. I run this file using Visual Studio and it works. in Visual Studio, to open and read a .txt file, i included fstream.h (#include <fstream>). in Acusolve, I want to start by having the user-defined function open the .txt file and read one value (baby steps), but when i try to compile, it is giving me lots of errors. in the C code, how do I include the fstream.h needed to open and read text files? thank you very much DensityTemperature_Column.txt fileReader.cpp methane_Density.c
  8. I am learning CFD and I have a problem that has density as a function of Temperature and Pressure. To start, I wrote a user defined function (usrMyDensity.c) where density is only a function of temperature (linear equation). I was able to compile the function and call it in my input file, but when i run a simple analysis (internal flow with constant temperature at the walls), i am not able to plot density in FieldView. I'm assuming that i'm not using the correct problem set up. I know that it is using the complied user function because initially it was giving me an error of negative density, which i fixed with an if statement in my user function. Any advice will be greatly appreciated. thank you for your time and patience usrMyDensity.c
  9. Thank you, akitoguc, that is cleaner code than what i had. I had two extra lines to achieve the same thing. I appreciate your time and help.
  10. I found another post that asked basically the same question ( using hm_measureshortestdistance2 works, I just need to figure out how to call the entity_id that it returns. for example, I created a mark of all my solids *createmark solids 2 1-1000 then I measured the distance between a node at (0 76 81) and all my solids with hm_measureshortestdistance2 0 76 81 solids 2 0 0 I get the following: 0 0 0 0 44 0 76 81 my solid id is 44, but how do I extract it? Thank you
  11. I'm new to TCL scripting, and I'm looking for a way to select a solid by its location. I looked into *createmark with the "by box"/"by cylinder" option, but they don't work for solids. "This is currently supported for nodes, elements, connectors, components (FE and connectors only), loads, equations, loadcols, systems, systcols, vectors, vectorcols, blocks, groups, sets and contactsurfs" - from Altair 14.0 documentation I would also use the same method to find surfaces to edit solids. Can somebody help with this?
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