JEC COMPOSITES MAGAZINE - Issue #135 - July/August 2020 - 58

SOLUTlONS aerospace

Lightweight liner-less carbon
composite subscale cryotank
We developed a liner-less carbon composite cryotank to achieve
a goal of over 25% weight reduction for space-purpose product
in place of the existing fuel tank.
Myeong Jin Kim,
R&D Team
Hankuk Carbon

A

s the self-developed project led by
Korea Aerospace Research Institute,
Hankuk Carbon designed and
produced Carbon Composites Subscale
Cryotank and conducted a cryogenic test for
verifying storage capacity of tank, including
pressure strength and airtightness.
Development background
In developing the carbon composites subscale cryotank, Hankuk Carbon and Korea
Aerospace Research Institute aimed to achieve
a goal of weight reduction over 25% compared
to the existing aluminum fuel tank and develop a cryogenic test technology at -182℃. The
cryotank, a liner-less pressure vessel, was manufactured by dry winding of carbon UD tapes
on a collapsible segment mandrel followed
by autoclave cure. The strength and tightness
performance of the carbon composites subscale cryotank was tested by a hydraulic test,
a helium detection test at low temperature
and high pressure using liquid nitrogen,
and a repeated hydro pressure test. Some
results required improvement compared to
requirements of cryogenic test so additional
development and supplementary work are
ongoing. To improve the performance of the
liner-less pressure vessel, the next step is to develop a tow prepreg or a carbon UD tape with
low gas permeability that could store liquid
oxygen and prevent leakage in place of a liner.
Then, the design capability will be improved

58

Development stages of the carbon composite subscale cryotank
- Size: Φ 550mm x L 600mm - Volume: 100-120 l - MEOP: 5.24 bar, burst pressure: 6.55 bar

to maintain the stable interface performance
between aluminum boss and the composite
layer under the cryogenic environments.
Main characteristics
The materials used for the carbon composite
subscale cryotank are carbon UD tape, epoxy
resin and aluminum. The liner-less pressure
vessel is manufactured combining dry winding technology and autoclave curing, using a
collapsible aluminum segment mandrel and
an iso-tensoid dome shape design.
Main advantages
The development of this new cryotank is
interesting for several reasons:
-	 The carbon manufacturing technology
makes it possible to eliminate the liner;
-	 A specific design and manufacturing tech-

jec composites magazine / N°135 July - August 2020

nology is used for the aluminum segment
mandrel;
-	 The cryogenic tank is lighter than the existing aluminum fuel tank for space-purpose
product;
-	 A specific design and manufacturing technology was developed for cryogenic liquid
oxygen tanks;
-	 The concept saves time and manufacturing
costs thanks to the dry winding process.
Potential applications
The target markets for this new development
are the aerospace industry, space application
composite, propellant tanks and high-pressure liquid oxygen fuel tanks for vehicles.
More information:
trade@hcarbon.com
JEC COMPOSITES MAGAZINE - Issue #135 - July/August 2020

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #135 - July/August 2020
