THEORETICAL MEAN WAVE RESISTANCE OF PRECURSOR SOLITON GENERATION IN TWO-LAYER FLOW

A new concept of pseudo mean wave resistance is introduced tofind theoretical mean wave resistances of the precursor soliton generation in two-layer flow over a localized topography at near-resonance in this paper.The pseudomean wave resistance of the precursor soliton generation of two-layer flow is deter-mined in terms of the AfKdV equation.From the theoretical results it is shownthat the theoretical mean wave resistance is equal to the pseudo mean wave re-sistance times 1/m;,where m;is the coefficient of the fKdV equation.Fromthe regional distribution of the energy of the precursor soliton generation at theresonant points,it is shown that ratios of the theoretical mean wave resistanceand regional mean energy to the total mean energy are invariant constants,i.e.;/:;/:;/:<D>/=（1/2）:（-1/2）:1:1,in which;,;and;are the mean energy of the generating regions of the precursor solitons,of thedepression and of the trailing wavetrain at the resonant points respectively,and<D>are the total energy of the system and the theoretical mean wave resistanceat the resonant points.A prediction of the theoretical mean wave resistances of two-layer flow over the semicircular topography is carried out in terms of the theoreticalresults of the present paper.The comparison shows that the theoretical mean waveresistance is in good agreement with the numerical calculation.