UWE Bristol Engineering showcase 2015

Michael Hartmann
Meng Aerospace Design Engineering
Project Supervisor
Dr. Chris Toomer
Design and evaluation of a wind tunnel test rig to investigate leading
edge suction for engine–airframe integration
Introduction
Aviation is subjected a steady expansion and predictions are indicating an even increasing growth rate leading to rising demand of fuel.
Thereby airport limitations due to noise and local air quality are impending this trend, whereas the increasing fuel prices cause higher
operational costs. These arising issues are guiding future aircraft designs, because the impact of commercial propulsion systems
becomes even more pronounced. Approaches to these expectations may rely on a variation from the common aircraft configurations
and change over to a consolidation of airframe and engine. Resulting synergy effects could then be exploited by closely coupling the
engines with the airframe. This project will take up this process and further investigates attainable improvements of integrated
propulsion and also directs the attention to arising drawbacks
The already present suction force on a aerofoil in motion
leads to the idea of mounting the engine close to the
wing, since an increased flow velocity of the inlet region
should cause a pressure drop, based on Bernoulli’s
equation. Hence, an increased suction should be noticed
at the LE, which is dependent on the lip shape.
Project summary
This project investigates the application of distributed
propulsion to an aircraft by performing wind tunnel
tests with an own developed integrated engine
design. It elaborates whether distributed propulsion
is feasible to improve propulsion systems of aircraft
being in service today by having a look at efficiency
criteria. The design of a test rig for later wind tunnel
tests is done and documented. First measurements to
judge the suitability of the test rig are conducted and
possible improvements are worked out.
Project Objectives
- Investigation of leading edge suction force variation
on test rig using the UWE wind tunnel
All investigations have been done in the wind tunnel of the
University of the West of England. Thereby, a variation of the
wind tunnel velocity, thrust setting and leading edge deflection
has been done, to work out overall improvements. By having a
tapping point based manometer indication implemented on
the test rig, the pressure distribution along the test section can
be evaluated.
The wind tunnel rig is equipped with four electric
driven fans, which are simulation real engines. As
these fans are located inside the box, the air is
sucked from the leading edge into the engine.
Therefore the leading edge suction force will
change and an improvement will be worked out.
Project Conclusion
Concluding, this investigation has shown
potential benefits of integrated engineairframe
design, by conducting a series of
wind tunnel tests using a tailored test rig.
Thereby, attention was directed to the LE
suction force, for which a dependency of LE
droop was investigated. The evaluation
process has suffered from certain errors of
the measurement systems, as well as,
coupling effects caused by the interference of
propulsion unit and wing section. Overall, this
project can conclude, the droop LE as not
being the only instrument to obtain a better
performance.