How to divide the global resistance change into the components related to the pushing propeller and the pulling propeller of the double-ended ship

The division of the global resistance change ΔR_R+D due to the simultaneous action of the pushing (SR) and pulling(SD) screw propellers into the components ΔR_R and ΔR_D can be done by taking into account two different procedures and different hypothetical assumptions given in the form of the division coefficients (A_j)_R and (A_j)_D, the same in each procedure.

In the procedure no1: ΔR_R = ΔR_R+D(A_j) and ΔR_R = ΔR_R+D(A_j)_Dj

In the procedure no 2: ΔR_R = T_R - (R₀ - F_D) (A_j)_R and ΔR_D = T_D - (R₀ - F_D) (A_j)_D Two necessary conditions were formulated to be fulfilled when selection of the coefficients (A_j)_R and (A_j)_D is done. The results of the analysis are univocal. Among the possible division coefficients only one pair of them fulfills the formulated conditions. This pair is: