1.First of all, thank you for your reply.
2.On the third day after I sent this post, I successfully installed and run v8p4.
3.Sorry I did not explain very clearly, I want to say that the ' flow field condition ' refers to the flow velocity that can be used for calculation at each point in the computational domain, their directions may not be consistent, they will change over time (similar to the attached figure), then how should I apply it to the calculation?
4.Thank you for sending the link, the user manual I have to see, I know the importance of the manual, I will learn more in the future.
Thanks again!