ORIGINAL PAPER
Evaluation of assemblability during aero engine preliminary design
J. Mall
1
•
S. Staudacher
2
Received: 30 March 2016 / Revised: 13 December 2017 / Accepted: 18 December 2017 / Published online: 19 January 2018
Ó Deutsches Zentrum fu¨ r Luft- und Raumfahrt e.V. 2018
Abstract
Despite the constant growth of global air traffic, the competition amongst airlines and their aviation supply chains
intensifies. In the future, stricter environmental regulations as well as economic goals will only be met by new aircrafts and
aero engines. In order to evaluate the life-cycle related cost at an early stage in the product design process, it is essential to
assess the manufacturability and assemblability during preliminary design. Through the assessment of assemblability,
major cost drivers can be identified in order to optimize the overall production cost. In this paper, a method to assess the
assemblability of different preliminary design variants is introduced. To achieve this, 2D cross sections of actual aero
engines are translated into 3D preliminary design models. Finally, an evaluation of the assemblability of different design
variants of low pressure turbine modules is conducted.
Keywords Aero engines Á Preliminary design Á Assemblability
Abbreviations
2D Two-dimensional
3D Three-dimensional
A
Ã
Independent assemblability parameter
A
E
Assembly efficiency coefficient
CAD Computer-aided-design
HPT High-pressure turbine
LPT Low-pressure turbine
M
PD
Mass of the preliminary design model
M
ref
Mass of the reference module
MTM Methods-time measurement
MRO Maintenance, repair and overhaul
OEM Original equipment manufacturer
ProKon Method for assembly oriented design
REFA Association for work design/work structure,
Industrial Organization and Corporate
Development
D
M
Deviation of the mass
1 Introduction
During the last decades, the aviation industry has under-
gone a significant change. The passenger yield of airlines
has been decreasing over the last three decades [32].
Consequentially, aero engines that competed mainly in
terms of performance and mass had to be economically
feasible as well [23]. This paradigm shift resulted from
increasing economic pressure on the airlines and their
supply chain.
Global passenger air traffic is expected to grow by
nearly 5% annually for the next two decades regardless of
increasing economic pressure or fluctuations in the market
[1, 5, 31]. In this context, new technologies will be needed
to reach the specified goals in terms of emissions and direct
operating cost [19, 22, 56]. Hence, the demand for new
airplanes and aero engines is high, while currently being
facilitated by low key interest rates [21]. The order books
of airplane manufacturers grow, whereas deliveries
increase only slightly. The resulting gap between actual
demand and production capacity leads to large production
backlogs. Moreover, forecasts predict a global fleet in 2032
that will consist of 85% new aircrafts and new aero engines
[5, 46]. To provide customers products on time, another
paradigm shift in aviation industry is required. In the
future, economically feasible aircrafts and aero engines
need to meet standards that will be accompanied by a
strong increase of production. Thus, the products need to
be industrially producible. To ensure this kind of
& J. Mall
jochen.mall@gsame.uni-stuttgart.de
1
Graduate School of Excellence Advanced Manufacturing
Engineering (GSaME), University of Stuttgart, Nobelstr. 12,
70569 Stuttgart, Germany
2
Institute for Aircraft Propulsion Systems (ILA), University of
Stuttgart, Pfaffenwaldring 6, 70569 Stuttgart, Germany
123
CEAS Aeronautical Journal (2018) 9:147–156
https://doi.org/10.1007/s13272-017-0278-8
(0123456789().,-volV)(0123456789().,-volV)
@Phil_Robichaud
@deepthiw
@JoseServera