Yes, But WHICH tables in the HDF are the ones with the velocity data.
The Face Velocity table gives a value for a single face at a particular time slice, but how would one go about finding the velocity vector for a cell ? I can picture adding the vectors for each face of a cell to get a cell velocity, but it is unclear how to get the vectors (i.e direction of the face velocity) from the hdf files. Would one use the Faces NormalUnitVector and Length table?
On a bigger topic, where are all these tables in HECRAS HDF tables defined. What is the relationship between them? How does one go about understanding how to use the information in the HDF files? Is there documentation or examples of how to use them? I have not found anything in multiple internet searches.
Computing the velocity vector at a cell is not straight forward. The finite volume solution has a method that does this by computing a velocity field. The RAS hydraulic reference manual discusses this.
I don't know that the RAS HDF tables are documented anywhere. For the most part, I have found them pretty self evident. I think if you want to use them, you are mostly on your own.