R.!> Поначалу видимо национальная особенность по гидродинамике
Вряд ли, скорей всего шум на большой скорости пытаются минимизировать.
Disclosed herein are exemplary embodiments of devices to attach to submarines or other water craft to enable a sonar array to function better at higher water speeds. When operated, the devices slow down or fully offset the mounted array's (hydrophones' or arrays') relative water speed and reduce the water friction noise on the array, allowing it to function more optimally. In an exemplary embodiment, a device includes a telescoping boom that can be alternately retracted and extended to provide cycles (or rotates to provide similar cycles for any one array) of higher performance reception and “hearing” by the array, as its relative water speed is reduced or offset. The device can be mounted on the external surface of the hull to “retrofit” existing craft or built so that in the telescoping embodiment, the housing can be fully retracted and hidden from view and otherwise protected more fully when not in use.
и здесь на 8 странице австралийцы мучаются вопросами:
Some Aspects of Submarine Design
Part 2. Shape of a Submarine 2026
Prof. P. N. Joubert