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WP3 – MAIN PROPULSION
Design of an electromagnetic propulsion system used to
catapult a MSV equipped with a ramjet
(WP3 - Main Propulsion)
Elliott SCHIRES - Abdullah SIMSEK - Benoît GARNIER - Christopher CHABERT-VEAU -
Tristan SARTON DU JONCHAY
ISAE, formation Ensica - Toulouse
Introduction:
Private companies dealing with
space tourism are currently using Manned
Suborbital Vehicle (MSV) exclusively equipped
with rocket engines. Yet, as soon as air is
available, the use of aerobic engines is
theoretically possible. In particular, the ramjet
engine is the most advantageous aerobic engine
at the required velocity to reach suborbital
altitudes. However, it cannot ignite itself because
of its architectural simplicity. An additional system
at low speed is required to ignite this engine. An
electromagnetic propulsion system, similar to
those used for the Japanese Maglev train, could
be an effective way to obtain frictionless
propulsion and reach high speeds with tolerable
acceleration. This project studies the feasibility of
such a propulsion system.
The Aerodynamic part
had to propose an
electromagnetic carrier design with criteria of drag
and had to determine the aerodynamic forces that
apply to the final system till the separation phase
between the MSV and carrier occurs at Mach 0.7.
The Separation between the MSV and its
carrier
represents a critical step in our project.
Without any carrier aircraft, we had to check that
the MSV would be able to gain enough altitude
after being catapulted, in order to ignite its ramjet
engine. The goal is to reach an optimal climb
trajectory while keeping the crew safe. A
kinematic simulation of this separation enabled us
to characterize the attitude of the vehicle and the
evolution of the aerodynamic forces, thus allowing
us to design an effective system.
The Structural part
proposes a shape for the
chassis of the carrier and a strap system to link
the carrier and the MSV. The goal is to ensure
structural integrity in order to bring the MSV from
Mach 0 to 0.7. Components are sized with respect
to inertial stresses due to the acceleration and the
aerodynamic forces determined in the first two
parts.
The carrier chassis
The Electromagnetic propulsion part
deals with
the choice of the propulsion system for the MSV
and its carrier and then its sizing. It is the same
principle that it is used in Linear Synchronous
Motor especially in Maglev trains. Moreover, a
control law has been defined to stabilize the
carrier and the MSV.
Linear Synchronous Motor
The Electromagnetic levitation part
deals with
the feasibility of Maglev levitation technology to
cancel any friction with the ground. Several
solutions have been considered of which only one
was viable: the use of superconducting coils
instead of metal coils. A feedback control on the
distance between the electromagnetic carrier and
the MSV was also carried out as part of this study.
To conclude,
this study showed that this
electromagnetic propulsion system has high
potential to initially propel an MSV equipped with
a ramjet engine and send tourists to the Karman
line, apart from a financial considerations.