[Gmsh] new to gmsh: Hints to get started

[Andrew C. Ward]

Dear gmsh list,

After using FIDAP for many years, I've today started looking at gmsh. I 
have some habits to break, and wonder if anyone might give me a hint to 
get me on my way, please?

My area of interest is bluff body flows, in particular atmospheric flows 
around low-set buildings. I've started in gmsh with a simple cube (based 
on the wind tunnel experiments of Castro and Robins more than 30 years 
ago). This was very easy, thanks largely to the superb interactive 
tutorial. In FIDAP, I have groups called inlet, outlet, cube, ground, 
side, top and symmetry.

gmsh kindly made me a beautiful looking mesh. By default, it's very fine 
throughout the domain, whereas I really only need it to be fine near the 
ground and around the cube. With FIDAP, I specify the starting element 
width, the number of elements and the geometric ratio of element widths, 
along a line leading from the cube outwards (I hope this makes sense).

I'd like to achieve the same effect in gmsh but just need a pointer to 
how I can get this happening.

Thanks so much for your advice.

Regards,

Andrew C. Ward