Multiphase Marine Ramjet Using Liquefied Gas as a Source of Bubbles

An innovative variant of a multiphase marine ramjet is investigated analytically and experimentally. Pressure liquefied gas (LG) is injected, boiling under superheat conditions in the water stream within the propulsion unit, and serving as an on-board bubble source necessary for the ramjet operation...

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Bibliographic Details
Main Authors: Herman D. Haustein, Alon Gany, Ezra Elias
Format: Article
Language:English
Published: MDPI AG 2020-09-01
Series:Journal of Marine Science and Engineering
Subjects:
Online Access:https://www.mdpi.com/2077-1312/8/9/710
Description
Summary:An innovative variant of a multiphase marine ramjet is investigated analytically and experimentally. Pressure liquefied gas (LG) is injected, boiling under superheat conditions in the water stream within the propulsion unit, and serving as an on-board bubble source necessary for the ramjet operation. Experiments were conducted in a 10 m diameter tow pool at a speed range of 7–18 m/s (approximately 14–35 knots). For the laboratory concept demonstration and process characterization, two liquefied gases, butane and R134a (synthetic refrigerant gas), were employed. In practical applications, non-polluting LGs such as liquid air may be used. The results reveal the overall performance comparable to the operation with pressurized air, with some thrust advantage of the LG at high-speed tests, attributed to the volume increase of gas during phase change, in accordance with the thermodynamic power cycle analysis.
ISSN:2077-1312