bodyType

customContents

entityId

entityUuid

articlePageQuery

filter

article

articleBaseAdvertisingInfoArticle

articleListArticle

articleSeoArticle

helpersCheckIsPostiesArticle

hooksArticleAcknowledgementGateOverlayArticle

hooksTrackPageViewArticle

hooksContentInterestArticle

articleLinkingDataContent

articleSchemaContent

liveArticle

advertZone

sentiment

contentLock

topics

types

sections

moreOnThisArticles

urlAlias

commentCount

sponsorType

authorLocations

authors

paywallTypes

corrections

displaySlideShow

multimediaEmbed

printHeadline

seriesContainer

socialHeadline

headline

flag

firstTopic

glossary

flattenTypeIds

publishedDate

additionalInfoBoxes

images

image

relatedLinks

relatedNewsletters

__typename

createdDate

sponsor

factSheets

series

disableOffPlatformContent

published

updatedDate

summary

subHeadline

body

keywords

copyrighted

customTimezone

liveContents

Stephen Chen

Chinese scientists have built the dream engine they proposed just two years ago.
The engine, originally meant for hypersonic weapons, has been modified so that it not only flies through the air, but can also then plunge into the sea to reach its target – at very high speeds and over long distances.
It does this by not only inhaling air, but also water, as oxidising agents.
In laboratory tests, the engine has achieved a nearly 90 per cent combustion efficiency while operating in submarine mode, meeting the requirements for practical use.
According to the research team, the development of the engine could alter the future landscape of warfare.
In 2022, scientists with the National University of Defence Technology (NUDT) in Changsha, Hunan province, proposed using this engine underwater. Cross-medium vehicles powered by such engines can fly at supersonic speeds for hundreds of kilometres in the air and dive into water to attack heavily fortified targets, such as aircraft carriers, at speeds exceeding 200 knots.
No country yet has the ability to intercept such weapons, they said.
The engine is powered by boron, a lightweight element used in scramjet engines – supersonic combustion ramjet engines – on some Chinese hypersonic weapons. When boron encounters oxygen in the air, it burns intensely, easily accelerating a missile to more than five times the speed of sound.
But one of the biggest challenges faced by the NUDT team was igniting the boron in water. To address this issue, they adopted a design that gives the solid fuel a second chance to burn, therefore boosting the engine’s overall efficiency.


They also optimised the injection volume of water vapour into the combustion chamber and the ratio of other ingredients in the fuel, such as magnesium and aluminium. These active metals enable boron to burn more thoroughly in vapour.
The scientists conducted the tests in a ground laboratory that simulates the underwater environment.
“There was a bright yellow, elongated tail flame near the outlet of the engine’s nozzle,” wrote the project team led, by Professor Huang Liya, in a peer-reviewed paper published in the Chinese-language Journal of Propulsion Technology last month.
“During the test, the flame and the pressure in the afterburner remained unchanged, indicating the engine’s stable operation.”
Data collected by sensors showed that the engine’s exhaust jet velocity exceeded Mach 3, with a combustion efficiency of 87 per cent.
When the proportion of boron fuel was increased in the fuel formula, its specific impulse reached 4,712 newton-seconds per kilogram, which is one-third more efficient than SpaceX’s latest Raptor rocket engine.
“Boron, as a propellant for cross-medium vehicle propulsion systems, holds broad application prospects and value,” the NUDT team wrote.
“Overall, the engine has achieved stable operation, validating the feasibility of the boron-based water ramjet engine.
“Next, we will increase the boron content in the solid propellant, optimise the engine’s combustion organisation, and further improve combustion efficiency and specific impulse.”


Desert ant shows Chinese team the way to high-definition polarised light sensor chip

How Chinese science and technology have influenced the West … and vice versa

The new aerial radar penetrating the icy depths of China’s glaciers

Chinese classicists battle to save Greek, Roman works from online conspiracy theories

Science

PLA fires up world’s first underwater boron ramjet for unstoppable anti-ship missiles

The world’s first underwater ramjet engine, powered by boron fuel, has been developed by PLA scientists. Photo: National University of Defence Technology

Chinese scientists propose ram-rotor detonation engine for hypersonic flight

The Chinese Journal of Aeronautics shows how the Tsinghua University team’s RRDE works. Photo: CJA journal

Typical structures of RRDE. Credit: Wang Bing

US report warns PLA electronic warfare could pose ‘significant challenge’ in Taiwan Strait

China’s air force operates J-16D electronic warfare fighter jets for radar jamming, according to a new US government report. Photo: AP

US sanctions put China’s military and civilian tech in bed together, researchers say

Chinese researchers found that on average, the transfer efficiency of China’s dual-use technologies more than doubled from 2015 to 2021.  Photo: Getty Images

World first as Chinese sample reveals ‘young’ volcanic activity on moon’s far side

Scientists have already made a major discovery after testing began on samples collected by China’s Chang’e-6 probe from the far side of the moon. Photo: CNSA/Xinhua via AP

Scientists around the world are excited by the samples brought back by the Chang’e-6 lunar probe, which was opened at a ceremony in Beijing in June. Photo: Xinhua

News

China

An engine that can carry weapons at incredible speeds through both air and water has been developed by Chinese scientists


An engine that can carry weapons at incredible speeds through both air and water has been developed by Chinese scientists.


China's military weapons

Hypersonic missiles and weapons