Abstract: This paper points out that on certain condition the reciprocal theorem is equivalent to the superposition principle of displacements. On the basis of [6], applications of the reciprocal theorem are further extended; a convenient, general and new method for solving the equations of deflection surface of the rectangular plates and the straight beams with various edge conditions under various loads is pie-sented.

Key words: mixing layers, coherent structures, FENE-P model, pseudo-spectral method