Propulsion System


Turbofan Engine Design

The preliminary design of the new DSL turbofan engine including the main target data has recently been published.

DSL turbo engine sketch

The engine target data at sea-level static condition is given in the following table

Overall Pressure Ratio

12.6

-

FAN Pressure Ratio (2 stages)

2.83

-

HPC Pressure Ratio (4 stages)

4.45

-

Two stage single crystal blade turbine

Turbine Entry Temperature TET

1900

K

Ram Combustor Exit Temperature T_AB

2200

K

Air mass flow

286

kg/s

Bypass-Ratio

0.22

-

Thrust dry / augmented

256.5 /337.2

kN

sfc dry / augmented

30.0 / 52.7

g/kNs

ISP dry / augmented

33300 / 18975

m/s

The design mass flow of 286 kg/s determines the fan face diameter of 1.43 m. Since the target data proposes a single spool type engine, the maximum rotational speed is restricted to about 6800 rpm. The front frame is supported by inlet guide vanes (IGV). It is followed by the two stage fan and the bypass frame with support #2 which also holds the power transmission shaft of the gear. The HPC consists of four stages with high pressure bleed air coming from the third stage. The combustion chamber is of high efficiency annular type. The aspired TET of 1900K should possibly be achieved, since similar values are proofed by experimental research. A two stage, fully air-cooled, single-crystal blade, high pressure turbine concludes the turbo-machinery part. This is followed by a high temperature afterburner/ram combustor in front of the exhaust nozzle. A cross sectional view of the components' arrangement and the overall dimensions are given in the figure above. The design should make use of the new metal matrix-, intermetallic matrix-, and ceramic matrix-composites (MMC, IMC, CMC) material.

Information about air-intake and nozzle design will be available soon. Data has been published at the 7th Intenational Space Planes and Hypersonic Systems and Technologies Conference in November 1996:

Sippel, M.; Pohl, M.: Considerations in Designing the Air-Breathing Engines for a Spaceplane Acceleration Mission, AIAA 96-4496, 7th Intenational Space Planes and Hypersonic Systems and Technologies Conference, Norfolk 1996 (Abstract)

Pre-Investigation of Propulsion System Design

Back to DSL Home Page


Last modification of this page: 16. December 1996

Contribution(s) to this page: Martin Sippel