We take Gt ¼ Gf ¼ 5/3 and Pi (i ¼ 1,2) is given in Equation (5). Equations (7) and (8) were derived after eliminating the other variables so that they describe 2 equations with 2 unknowns: k1 and k2. The solutions of the compressions k1 and k2 are given in Fig. 3 for r0t/r0f ¼ K ¼ 1000.