ITTC-78 powering procedure

The ITTC-1978 performance prediction method is the standard route from a model resistance and self-propulsion test to full-scale power. It splits the total resistance coefficient as C_T = (1+k) C_F + C_W, takes C_F from the ITTC-1957 line, finds the form factor (1+k) by Prohaska’s low-speed plot, holds C_W constant at equal Froude number, then adds a roughness allowance delta C_F and a correlation allowance C_A at ship scale. Propulsion factors (wake fraction, thrust deduction, relative rotative efficiency) come from the self-propulsion test, with scale corrections, to give delivered power P_D and shaft power. It is the basis for predicting trial power before sea trials.