Periodic and Solitary Wave Solutions of Two Component   Zakharov-Yajima-Oikawa System, Using Madelung's Approach
  Using the multiple scales method, the interaction between two bright and one dark solitons is studied. Provided that a long wave-short wave resonance condition is satisfied, the two-component Zakharov-Yajima-Oikawa (ZYO) completely integrable system is obtained. By using a Madelung fluid description, the one-soliton solutions of the corresponding ZYO system are determined. Furthermore, a discussion on the interaction between one bright and two dark solitons is presented. In particular, this problem is reduced to solve a one-component ZYO system in the resonance conditions. 
Anca Visinescu, Dan Grecu, Renato Fedele, Sergio De Nicola
nlin.SI