The Tecplot data can be read in general as follows.
For example, for:

 I=61, J=77, K=1, ZONETYPE=Ordered
 DATAPACKING=BLOCK

the data can be read from the files (ignoring title, zone,
variables, and other header lines) via:

      idim=61
      jdim=77
      read(2,*) ((x(i,j),i=1,idim),j=1,jdim)
      read(2,*) ((y(i,j),i=1,idim),j=1,jdim)
      read(2,*) ((z(i,j),i=1,idim),j=1,jdim)
      read(2,*) ((u(i,j),i=1,idim),j=1,jdim)
      read(2,*) ((w(i,j),i=1,idim),j=1,jdim)
      read(2,*) ((vel_abs_2d(i,j),i=1,idim),j=1,jdim)