**Ladislav Illes 1, Tomas Kalina 2, Martin Jurkovic 2,\* and Vladimir Luptak <sup>3</sup>**


Received: 13 July 2020; Accepted: 24 August 2020; Published: 29 August 2020

**Abstract:** The aim of this study was to investigate the impact of distributed propulsion systems used on inland and coastal navigation in shallow water. Five layouts were assessed by computational fluid dynamics (CFD) simulation. The hull/propulsion layout cases have been analyzed for discrete flow speed values in the range 0–6 m/s. All cases have been examined under restricted draft conditions in shallow water with a minimum of 0.3 m under keel clearance (UKC) and under unrestricted draft conditions in deep water. The results show that distributed propulsion consisting of 6 or 8 (in some cases, even more) units produces noticeable higher thrust effects in shallow water than the traditional layout. Under restricted conditions, the thrust increase between two distributed layouts with different numbers of propulsors is higher, in contrast to deep water, where differences in performance are not so significant.

**Keywords:** distributed propulsion; draft; shallow water; computational fluid dynamics
