COMPUTER MODELLING & NEW TECHNOLOGIES 2014 18(3) 93-97 Chen Longmiao, Fu Qiang, Lin Gui
93
Mathematical and Computer Modelling
Study on the sealing properties of the sealing structure for the
rotating chamber of a certain cased telescoped ammunition gun
Longmiao Chen
, Qiang Fu, Gui Lin
College of Mechanical Engineer, Nanjing University of science and technology, Nanjing 210094, Jiangsu, PR China
Received 1 March 2014, www.tsi.lv
Abstract
To solve the spherical transient high pressure gas seal problem for the rotating chamber of a certain medium calibre cased telescoped
ammunition gun, a self-impacted combined sealing system was newly designed which can be placed at semi combustible cartridge of
the cased telescoped ammunition. The sealing mechanism of the structure was analysed and simulation studies on the comprehensive
properties of the sealing structure were carried out via the FEM dynamic response. In addition, the simulation and verification tests
were conducted to test the sealing performance of the sealing structure. The results of the simulation analysis and the experiments
demonstrate that the designed sealing structure has a good sealing performance and can solve the spherical transient high pressure
gas seal problem for the rotating chamber of the medium calibre cased telescoped ammunition gun, and it is expected to offer a
reference value to solve related problems in engineering.
Keywords: Sealing for the Rotating Chamber, FEM, Test Verification, Cased Telescoped Ammunition
Corresponding author e-mail: 13913870745@139.com
1 Introduction
Cased telescoped ammunition (CTA) gun is a kind of
artillery, which use an integrative ammunition with the
projectile embedded in simple cylinder cartridge case.
The most important feature of CTA is its regular
ammunition shape and short length. CTA gun commonly
use new latching principle of rotating chamber, which
will compact the loader structure, and reduce the overall
size of the artillery systems [1, 2]. Due to the separate
design of CTA chamber and the gun tube, and the
frequent rotation of opening and closing, this special
structure is inevitable to make there a gap between the
chamber and the spherical interface of barrel ends. If
there is no reliable sealing structure, the condition of
pressure up to 400 MPa and temperatures up to 3000K in
the bore and rotating chamber will lead to gas leak and
serious effect on gun performance which contains great
security risks. Thus, the seal problem for the rotating
chamber of a CTA gun is a key technology, which must
be resolved [3].
Rotating chamber high temperature and high-pressure
gas make a great impact on the seal member in a very
short period, which is a typical transient high-pressure
seal problem at the gap of the spherical interface. In this
paper, a self-impacted combined sealing system was
newly designed which can be placed at semi combustible
cartridge of the CTA. The sealing mechanism of the
structure was analysed and simulation studies on the
comprehensive properties of the sealing structure were
carried out via the FEM dynamic response. In addition,
the simulation and verification tests were conducted to
test the sealing performance of the sealing structure.
2 How to use the template
The self-impacted combined sealing structure is placed at
a non-combustible structure of both ends of semi
combustible cartridge of the CTA. The structure is shown
in Figure 1. Taking into account the similarities of the
sealing structure and the mechanism between both ends
of the cartridge, only the front sealing structure of the
cartridge is analysed. There are three major leakage
channels A, B, C in the sealing structure as shown in
Figure 1. The sealing mechanism is as follows [4]:
FIGURE 1 Schematic Diagram of Sealing System
Channel A: the special design of spoon-shaped metal
ring makes generated gas quickly spread to the spoon-
shaped area before the gas into the channel A. In
addition, relative to the "spoon" area, channel A is just a
small gap, so the right force along the barrel axial of
metal rings is much larger than the left. At the beginning
period of gunfire, the gas can quickly push the metal ring
moving right along the barrel axis to meet the barrel end,
