Thank you sir, this is very informative and useful video I have one query i am using ANSYS fluent 2019, in which i am solve the hemodynamic blood flow problem in artery. Here i need to calculate the Average Wall Shear Stress expressed as : AWSS = 1/T 0ʃT |WSS| dt please suggest me how to do this calculation or extract the result for AWSS by defining some function in fluent.
Hi Hesham, Really great alternative to UDF. In my expression, there are two variables coming 1. The temperature at old-time step and 2. Heat transfer rate on the outlet. Can I get any details on this?
Thank you for this very informative lecture. Sir, I have one query. Sir, during simulation, if there is any negative pressure is generated then that negative values I want to make it zero. So that I won't get any negative pressure after the solution is converged. (What i mean is, all calculated negative pressure and their gradients should be equal to zero throughout the iteration). How can I do it ( by writing expression or any other possibility)? Sir, I don't have any specific expressions for doing this so that I can directly add that expression. Thank you. Waiting for your kind reply
Thank you for your sharing knowledge. I have one query sir. Do we know the saturation times of adsorbent (porous media) by single gases if time related only the concentration of gas?
I have a small query, i want my inlet to be a sinusoidal pressure inlet (like p*sin(w*t) ) . w is frequency in radian and t is time. Could you guide me please.
First of all, I would likte to thank you sharing the very useful video. But I could not compile the expression of temperature dependent thermal conductivity. Fluent tried to get constant value.
@@h4ienglish I am trying to write the heat conduction coefficient function depending on the temperature. k (T) = a + b * T ^ 0.5 + c * T ^ 1.5. When I write this expression in named expressions, it says that this expression should be entered as a constant value.
You can specify thermal conductivity as function of temperature using the option "Polynomial" and the coefficients must be constants. It seems that material properties do not support expressions. If you want to specify it as a variable in other properties, you have to use "User defined functions".
@@h4ienglish Since T has no exponential forces 1 and multiples, I can not define it as a polynomial. I will try to write UDF. Thank you very much for answering.
Hi and thanks for the tutorial. In a case that I have, I need to change the boundary condition during the simulation, after a certain time, from velocity_inlet to wall. I'm wondering how I can set FLUENT2021 in this regard. Thanks in advance.
@@h4ienglish I don’t want to change the value. I need to change the type of boundary condition (velocity-inlet -> wall). I think it could be done through the “Execute Commands” however, I need to learn how to write its code on FLUENT. Would you please give me some hints?
can you help me with plotting schlieren images. i'm calculating magnitude of gradient of density. when i plot in contour. it all show white background. ofcourse values are calculated but i cab present in contours
hello sir, this is very useful session for me. sir i have one query : i want to give a inlet velocity profile as (0.05 sin (wt) +0.57685) so that i have defined omega=4PI/1[s] and then the profile : (sin(omega*t)*0.05+0.5768593457) then this msg rises Incorrect expression unit. Expression Unit [], Required Unit [m s^-1] please help
Thank you so much for this detailed explanation. I have tried adding a body force for a VOF model the expression is as follow: -3675000[N/m^3]*volumefraction Although the syntax is correct, I receive an error message "Invalid expression: -3675000[N/m^3]*volumefraction" Any Idea what might be wrong?
I have figured out the problem . The expression should be written as following “ -3675000[N/m^3]*Volumefraction(phase=“water”) “ Where water is the phase name. Thanks!
Thank you for sharing this video. I wonder if this new alternative can also be used to write dynamic mesh expressions directly instead of writing UDF code? Thank in advance.
@SEVERIN TINMITONDE , sir did you do it by now??..........I need to know since my thesis needs complex dynamic meshing equations..........please tell me if it's possible
Hello! I liked too much your video and i believe that it will be very useful at my research. Moreover, i would like to ask for you help. I'm simulating in ANSYS Fluent a simulation from a Report. At this Report, the author use The density and viscosity as a function of methanol mass fraction, like a equation with like variable the mass fraction. Can you help with with this? i'm already thankful, in advance, for any help..
@@karendanyele3962 Sure, please contact me on the Facebook page "H4I software services", we can exchange any information there. It is safer than the RUclips comments section.
Very useful information. it is a common situation that you will likely face in modeling. Big thanks.
Glad it was helpful!
**2 to represent ^2! Thanks for mentioning this. I have been struggling with inputting a polynomial due to missing out this code.
Glad it was helpful!
Thank you sir, this is very informative and useful video
I have one query
i am using ANSYS fluent 2019, in which i am solve the hemodynamic blood flow problem in artery. Here i need to calculate the Average Wall Shear Stress expressed as :
AWSS = 1/T 0ʃT |WSS| dt
please suggest me how to do this calculation or extract the result for AWSS by defining some function in fluent.
I will look into it
Hi Hesham, Really great alternative to UDF. In my expression, there are two variables coming 1. The temperature at old-time step and 2. Heat transfer rate on the outlet.
Can I get any details on this?
I am not sure if it is possible using expressions.
Thank you for this very informative lecture. Sir, I have one query. Sir, during simulation, if there is any negative pressure is generated then that negative values I want to make it zero. So that I won't get any negative pressure after the solution is converged. (What i mean is, all calculated negative pressure
and their gradients should be equal to zero throughout the iteration). How can I do it ( by writing expression or any other possibility)? Sir, I don't have any specific expressions for doing this so that I can directly add that expression. Thank you. Waiting for your kind reply
Sorry, but I do not know how I can achieve this.
Thank you for your sharing knowledge. I have one query sir. Do we know the saturation times of adsorbent (porous media) by single gases if time related only the concentration of gas?
I don't get the question.
thank you, it is very helpful.
Glad it was helpful!
is this method able to define oscillating motion of a body ? without dynamic mesh
I don't think so, but I am not sure.
I have a small query, i want my inlet to be a sinusoidal pressure inlet (like p*sin(w*t) ) . w is frequency in radian and t is time. Could you guide me please.
I think it can be done. Did you try to define this equation as described in the video?
I used a udf , that is from ansys manual but didn't got the desired results..
If you wish, I can help you with the UDF, but it is a paid service.
You can contact me through the Facebook page, H4I software services.
Thank you for this video. It is very helpful. Can this be used to model new drag /lift model coefficients as done using UDF?
I did not try it myself, but I think it is possible.
Thank you so much for sharing this video.
You are so welcome!
First of all, I would likte to thank you sharing the very useful video. But I could not compile the expression of temperature dependent thermal conductivity. Fluent tried to get constant value.
I need more information, what is the error?
@@h4ienglish I am trying to write the heat conduction coefficient function depending on the temperature. k (T) = a + b * T ^ 0.5 + c * T ^ 1.5. When I write this expression in named expressions, it says that this expression should be entered as a constant value.
You can specify thermal conductivity as function of temperature using the option "Polynomial" and the coefficients must be constants. It seems that material properties do not support expressions.
If you want to specify it as a variable in other properties, you have to use "User defined functions".
@@h4ienglish Since T has no exponential forces 1 and multiples, I can not define it as a polynomial. I will try to write UDF. Thank you very much for answering.
Can I contact with you for some explanations please?
Sure, my email is in the video.
I sent email to you 🌹
Hi and thanks for the tutorial. In a case that I have, I need to change the boundary condition during the simulation, after a certain time, from velocity_inlet to wall. I'm wondering how I can set FLUENT2021 in this regard. Thanks in advance.
Yes you can use conditional statements to change values with time
@@h4ienglish I don’t want to change the value. I need to change the type of boundary condition (velocity-inlet -> wall). I think it could be done through the “Execute Commands” however, I need to learn how to write its code on FLUENT. Would you please give me some hints?
can I use expressions in post processing ?
for example a user defined variable including integration
Yes you can use expressions in defining new variables
how can define( gamma )shear rate strain .... with expression ...in comsol i can do it with write spf.sr....
I don't know, I never did it before.
Hello, I want to 5mm³ volume water inlet with velocity 0.12242125m/s how can I do that
I don't understand
can you help me with plotting schlieren images. i'm calculating magnitude of gradient of density. when i plot in contour. it all show white background. ofcourse values are calculated but i cab present in contours
Sorry, I am very busy
hello sir, this is very useful session for me.
sir i have one query : i want to give a inlet velocity profile as (0.05 sin (wt) +0.57685)
so that i have defined omega=4PI/1[s]
and then the profile : (sin(omega*t)*0.05+0.5768593457)
then this msg rises
Incorrect expression unit. Expression Unit [], Required Unit [m s^-1]
please help
This kind of help is provided as a paid service. If you are interested, please contact me through Facebook page "H4I software services".
Thank you so much for this detailed explanation. I have tried adding a body force for a VOF model the expression is as follow: -3675000[N/m^3]*volumefraction
Although the syntax is correct, I receive an error message "Invalid expression: -3675000[N/m^3]*volumefraction"
Any Idea what might be wrong?
What is the units of the volumefraction?
I have figured out the problem . The expression should be written as following “ -3675000[N/m^3]*Volumefraction(phase=“water”) “
Where water is the phase name. Thanks!
Thank you for sharing this video.
I wonder if this new alternative can also be used to write dynamic mesh expressions directly instead of writing UDF code?
Thank in advance.
I do not know, I have no experience with dynamic mesh.
@SEVERIN TINMITONDE , sir did you do it by now??..........I need to know since my thesis needs complex dynamic meshing equations..........please tell me if it's possible
Hello!
I liked too much your video and i believe that it will be very useful at my research. Moreover, i would like to ask for you help. I'm simulating in ANSYS Fluent a simulation from a Report. At this Report, the author use The density and viscosity as a function of methanol mass fraction, like a equation with like variable the mass fraction. Can you help with with this? i'm already thankful, in advance, for any help..
I am very busy right now. If you are not in a hurry you can contact me after a month. May be I can help then.
@@h4ienglish This would be really good. Can you give your email? Or, if you want, my email is karen.vieira@UFPE.br
Thanks, in advance,
Karen.
@@karendanyele3962 Sure, please contact me on the Facebook page "H4I software services", we can exchange any information there. It is safer than the RUclips comments section.
How can i write an expression for velocity =3.5 cos (pi* time ) ???
Best regards
I can send you the complete list of variables' syntax. Send me a message through my Facebook page (H4I software services).
is there any link for this version of ansys ?
If your domain is small, you can get the academic version for free from the official website.
where pdf file?
Please contact me on the Facebook page. H4I software services
how can we add expressions in ANSYS 19.1 version
I don't think it is possible
shear rate strain ???
I don't know, check documentation.
Sir can you please share the Pdf
Yes I can, contact me through mail or facebook
can you please drop your mail id .
@@kakkiralavenkatesh it is in the video