[sampy]

Hi,
I have a UDF which inherits spray properties. I have to implement a time-varying cone angle. How do I interpolate the values from the time? What is the table lookup function for interpolating time-varying data? I am converge v3.0.24.
Thanks,
Sampath

[ksrivast]

Hello Sampath,

May I know why you're looking at a UDF option for this? In CONVERGE Studio, you can provide a time-varying profile for spray cone angle for each nozzle using the Use file option. During the simulations, CONVERGE will (linear) interpolate between the values provided.

Hope this helps.

Sincerely.

[sampy]

Hi Kislaya,
I am modifying an existing in-house UDF to include the spray-angle. In this UDF, we have a variable that reads the injector and nozzle data structures for some operations. As part of this process, I have to read the time-varying cone angle from a file. So, I just need to pass the interpolated cone angle from the table.


It is my understanding that I can read this information using the following pseduo code:
var1 = CONVERGE_table_lookup(CONVERGE_<some_data_structur e>_table, simtime+start_time);


Can you suggest what are the arguments I need to pass to table_lookup?
Thanks,
sampath

[ksrivast]

Hello Sampath,

The time-varying cone angle file that you provide, is it using the Use File option for Spray cone angle, or a user input file?

You can feed the profile using the Use File option during setup and obtain the cone angle at current time-step using the CONVERGE_nozzle_get_parameter_precision(nozzle, NOZZLE_CONE_ANGLE) API. Some UDF routines also pass the current cone angle as "passed_cone_angle". You can refer the calc_dynamic_spray_cone_angle.c and nozzle.c example UDFs.

If you're using a user input file, it might be better to create your own routines to find an interpolated value. With the API you mentioned, you'll have to store your data within an CONVERGE _table_t variable and pass it as an argument to the API.

There might be better ways to obtain what you're looking for once we get an idea on how these UDFs work. For assistance, please contact support@convergecfd.com. Please use your official email for all correspondence with Convergent Science. Please mention the issues you are facing, attach your case setup along with the UDFs and add the cfd-online thread, as reference.

Sincerely,

[sampy]

Hi Kislaya,
Thank you for pointing me to the appropriate example files. I am using the use file option for passing the cone angle table. I will try using the examples, if it is still unresolved I will reach out with a support request.
Thanks,
Sampath