Editor's foreword

In his preface, the editor-in-chief draws the reader's attention to two special materials included in the current issue of the journal. In particular, this concerns the article by O. M. Stetsenko and V. M. Ilchenko “Applying the velocity potential of a two-source system to the problem of a thin ship moving in a rectangular channel with time-varying speed”. Unfortunately, Oleksandr Grygorovych passed in 2021 after a long illness, but his colleague continues the creative development of his supervisor’s ideas. Also separately mentioned is the article by I. V. Vovk and V. S. Malyuga “Analyzing the features of self-excited oscillations generated by the flow past a circular cylinder with a splitter plate”. A talented scientist-mechanic Volodymyr Malyuga volunteered to defend our country at the beginning of the full-scale Russian-Ukrainian war. In April last year, he went missing at the front. At the request of the Editorial Board, his scientific supervisor, Prof. I. V. Vovk, completed work on a joint manuscript, which is now presented to the scientific community.