Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Performance analysis of a new helical channel seawater MHD thruster
X. Q. Chen1; L.Z. Zhao1,2; and A.W. Peng1,2*
1. Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China
2. University of the Chinese Academy of Sciences, Beijing, China

inlet flow-guide changes the axial flow into a helical flow, and therectifiers change the helical flow into an axial flow. As shown in Fig.1,
the helical channel is matched with the solenoid superconducting
magnet to form a helical superconducting MHD thruster. The solenoid
superconducting magnet generates an axial magnetic field, the current
along the radial direction, and generates an electromagnetic force in thecircular direction, which promotes the flow of seawater along with thehelical blades.

ABSTRACT
Aiming at the problem that the hydraulic loss of the traditional helicalchannel (Axial inlet and outlet of the seawater) is large and themagnetic leakage of the superconducting magnet is difficult toeliminate, this paper designs a new type of helical channel whose inlet
and outlet channels are a tangent extension of helical blades, and puts
forward a new installation mode with more practical significance. The
fluid dynamics software FLUENT is used to conduct three-dimensional
numerical calculations and comparison between the new helicalchannel MHD thruster and the traditional helical channel MHD thruster.
The results show that the hydraulic loss coefficient of the new thruster
is about 23% lower than that of the traditional thruster; At the sameflow rate, the pressure rise of the new thruster is increased by 23.57%,
the total efficiency is increased by 23.81%, and the uniformity of theoutlet flow field is increased by 24.03%.

In the traditional thruster, if the inlet flow-guide can not convert theaxial flow into spiral flow well, there will be great hydraulic loss in theeffective section of the helical channel; Changing the spiral flow into
axial flow will increase the hydraulic loss of the channel, and therectification effect of the outlet flow-guide has a direct impact on thethrust and operating characteristics of the thruster. These characteristics
lead to the large flow loss of the traditional thruster, which leads toflow propulsion efficiency.

KEY WORDS: Seawater MHD thruster; new helical channel;

Combined with the traditional arrangement of MHD thruster withhelical channel and the magnetic field distribution of solenoid
superconducting magnet (Zhao L Z, 2013), The superconducting
magnet will produce large magnetic leakage in the axial direction of thehelical channel, which is also a factor restricting the practicability ofthe MHD thruster with a helical channel.

hydraulic loss; pressure rise; propulsion efficiency; numericalsimulation; fluent

INTRODUCTION
Seawater MHD propulsion is a new type of ship propulsion, which has
high quietness and can realize the characteristics of ultra-high powerand high-speed ship propulsion. At present, the structural forms of theMHD thruster channel are mainly linear channel (Al-Habahbeh O.M. etal., 2016; Cebron D et al., 2017; Haghparast M et al., 2018; Haghparast
M et al., 2019; Chan C S et al., 2020; Li Y H et al., 2021) and helicalchannel(Chen X Q et al., 2020; Chen X Q et al., 2019; Chen X Q et al.,2021; Haghparast M et al., 2019; Zhao L Z, 2013;).Helical channel
MHD thruster adopts solenoid superconducting magnet and helicalchannel; Solenoid magnet can realize high field and large temperature
hole size. The helical channel improves the effective length ofelectromagnetic force and then improves the thrust density. It is themost studied and most practical MHD thruster at present.
The traditional helical channel (Axial inlet and outlet of the seawater) is
mainly composed of inlet and outlet insulating walls, cylindrical innerand outer electrodes, inlet flow-guide, helical blades, and rectifiers; theFig.1 Physical model of the traditional helical channel MHD thruster

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