The gradient of void fraction in UDF
 

Hello, everyone. Now I used the UDF to define the gradient of void fraction as follows: if(NULL!=THREAD_STORAGE(mix_thread,SV_VOF_G)) { v_s=C_VOF_G(c,thread_g)[1]; //Message()"it is OK!%f\n",v_s); } Next, I would like to multiply this gradient of void fraction into velocity(two vectors). In math, I know we could multiply them in x, y direction, respectively. How can I realize this since I do not know how to get the expression of this gradient in x and y direction? (Now I am using 2d) Thanks in advance.

Re: The gradient of void fraction in UDF
 

Do you want scalar multiple product , for example A & B by udf?

Hi friends,
I'm simulating a tube with water flow.
The tube encounters boiling near the wall.
I intend to calculate 'void fraction versus enthalpy' along the channel.
Can you help me how to calculate void fraction?

I'm in an emergency condition.
Waiting for your comments!!!

Thanks Everybody