Steam Tables (Table 3. Vapor, page 18)

                       

                                     differences in flow pattern and general behavior,

having significantly different physical characteristics.

= (e_ji + w_ij) A_j,                                                 combustion or evaporation,

             e_ji = ½ (u_j,i + u_i,j),                   w_ij = ½ (u_j,i - u_i,j).

the e_ji and w_ij were constants and so small that their products < 0

                                                                                   

                                                                                         1   2            1   2 

                                                                                    e₁ A_j A_j  = e_jk  A_k A_j