Case Study 4: Novel optimisation significantly reduces costs, increases turnover and reduces emissions
Submitting InstitutionUniversity of Leeds
Unit of AssessmentCivil and Construction Engineering
Summary Impact TypeTechnological
Research Subject Area(s)
Mathematical Sciences: Applied Mathematics, Numerical and Computational Mathematics, Statistics
Summary of the impact
Optimisation tools developed in the UoA have significantly advanced the
ability to find the best designs for complex systems in cases where these
were previously unobtainable. These optimisation tools have been
implemented in several companies to shorten design times, reduce costs and
reduce CO2 emissions. This has brought about new multi-million
pound revenues, long-term contracts, increased employment and contribution
to sustainability targets.
Since 2006 the UoA (Toropov, Polynkin) has developed and applied a range
of optimisation methodologies that have enabled the wider use of
optimisation in industry which in turn has delivered enhanced products and
processes. This has focused on metamodelling and improved sampling.
Metamodelling-based optimisation and stochastic analysis are used
in situations where even a single numerical simulation of a system or a
complex process is not possible due to any of: excessive computing time;
response polluted by numerical noise; instabilities in the calculations.
These problems are exacerbated by the fact that an optimisation run or a
Monte Carlo simulation requires many simulations rather than just one. In
view of this the only realistic way of addressing such problems is to
build high quality "emulators" or "metamodels" to mimic the full model.
These (i) describe the behaviour of the system (or a process) with
sufficient accuracy as compared to a full simulation, (ii) are
computationally inexpensive and (iii) do not possess any significant
amount of numerical noise. When such metamodels are obtained and,
importantly, their quality is verified, they can be used in optimisation
or a Monte Carlo simulation in place of the original, significantly more
In order to build a metamodel it is necessary to perform sampling
by running a sufficient number of numerical simulations in the space of
optimisation variables and/or stochastic factors according to a carefully
chosen design of experiments (DOE). Experiments normally refer to
numerical simulation at various combinations of optimisation or stochastic
variables, but research in the UoA demonstrated that this may also include
laboratory experiments . Uniform designs of experiments that are based
on the concept of an optimal Latin hypercube have been developed in the
UoA with the intention of gathering as much information on the behaviour
of the system (or a process) as possible with a minimum number of sampling
points thereby ensuring fidelity but with minimum computer time. These
innovative methods include nested DOEs, i.e. individual uniform DOEs that
are used separately for metamodel building and validation and can then be
merged while remaining uniform . This research was carried by Toropov
at Leeds out in collaboration with Altair Engineering and Bradford
Key metamodelling techniques developed by Toropov and Polynkin include:
- Metamodel building using the concept of Moving Least Squares Method
(MLSM) that is a technique flexible enough to describe the sampling data
with high accuracy when the amount of numerical noise is small but also
has the capability of filtering out numerical noise when it becomes an
issue. This has been a basis for a multidisciplinary optimisation
- Metamodelling, based on the interaction of low- and high-fidelity
simulation models, that is beneficial for creating high quality
metamodels when a lower complexity simulation model is available in
addition to the original high fidelity simulation model. In such case
the metamodel can be based on the low fidelity model which is corrected
and tuned using only a small number of runs of the high fidelity model
. This research was done by Toropov in collaboration with Hiroshima
Another major research outcome in the UoA has been the development of a
large-scale optimisation technique (hundreds of design variables) based on
the mid-range approximation method (MAM) utilising a trust region
strategy. In order to deal with the "curse of dimensionality",
approximations in MAM are based on the class of intrinsically linear
functions and also include simple rational functions and moving least
squares approximations with a linear base function. The final
approximation is arrived at using an adaptive selection and
regression-based model assembly . This research in the UoA has been
funded jointly by TSB, Rolls-Royce and Airbus.
Another aspect of fundamental research has been the development of the
methodology for the composite optimisation of large scale structures. This
optimisation problem is too large to be solvable by existing means and the
optimisation method (developed by Toropov and applied by researchers from
the School of Mechanical Engineering at Leeds) reduces this complexity to
a manageable level . This work was done within an EU FP-7 project
The techniques described here give a suite of optimisation techniques
that have been applied by the University of Leeds to a wide range of
applications which have generated significant impacts some of which are
set out in Section 4.
Key researchers in this work were:
- Vassili Toropov, Professor: 01/04/2006 — present.
- Andrey Polynkin, Research Fellow: 17/04/2007 - 30/11/11
Researchers outside the UoA were:
- Harvey Thompson, School of Mechanical Engineering: Research Fellow,
1995-2000; Lecturer, 2000-04; Senior Lecturer 2004-11; Professor,
- David Barton, School of Mechanical Engineering: Professor, 01/01/85 to
- Osvaldo Querin, School of Mechanical Engineering: Lecturer, 13/6/2000 - 31/7/03;
Senior Lecturer, 1/8/03 - 1/10/12, Associate Professor,
1/10/12 — present.
List of key awards that supported the above research (amounts are the
University of Leeds share): EU:
- AMEDEO (Aerospace Multidisciplinary-Enabling Design Optimisation),
- ALASCA (Advanced Lattice Structures for Composite Airframes),
- Design of Super-impactors, £377,431, 2009.
- SILOET-II, £256,001, 2013.
- EADS UK Ltd. KTP, £163,615, 2010.
- Airbus IM KTN, £14,950, 2011.
References to the research
 Vu, H.M., Forth, J.P., Dao, D.V. and Toropov, V.V. The use of
optimisation for enhancing the development of a novel sustainable masonry
unit. Appl. Math. Modelling, DOI: 10.1016/j.apm.2013.07.026
 Narayanan, A., Toropov, V.V., Wood, A.S. and Campean I.F.
Simultaneous model building and validation with uniform designs of
experiments. Engineering Optimization, 39(5): 497-512, 2007, DOI:
 Zadeh, P.M., Toropov, V.V. and Wood, A.S. Metamodel-based
collaborative optimization framework. Structural and Multidisciplinary
Optimization, 38, 103-115, 2009, DOI: 10.1007/s00158-008-0286-8
 Hino, R., Yoshida, F. and Toropov, V.V. Optimum blank design
for sheet metal forming based on the interaction of high- and low-fidelity
FE models, Archive of Applied Mechanics, 75(10-12): 679-691, 2006, Invited
paper for the special issue on the 75th anniversary of the journal, DOI:
 Polynkin, A. and Toropov, V.V. Mid-range metamodel
assembly building based on linear regression for large scale optimization
problems. Structural and Multidisciplinary Optimization, 45 (4): 515-527,
2012, DOI: 10.1007/s00158-011-0692-1
 Liu, D., Toropov, V.V., Querin, O.M. and Barton, D.C Bilevel
optimization of blended composite wing panels. AIAA Journal of Aircraft,
48(1): 107-118, 2011. DOI: 10.2514/1.C000261
Note: Authors from the University of Leeds in bold.
The three papers selected to demonstrate the quality of the underlying
research are ,  and . They are published in
internationally-recognised leading journals and have attracted
significant interest through citation and take-up by other researchers.
Details of the impact
The metamodel-based optimisation methods developed in the UoA and
described in Section 2 have been combined with high fidelity Computational
Fluid Dynamics analysis (Thompson, School of Mechanical Engineering,
University of Leeds) to develop new product design optimisation software
[A, B, C]. A transformation of the design variable space was proposed that
has dramatically improved the fidelity of the metamodel without an
excessive number of CFD simulations thus providing a practical tool for
the pump designers [A].
Based on research in the UoA the company developed software which they
then used to increase the efficiency of their jet pumps by 20% [A]. From
2010 this optimisation software was applied to the new Racor Super
Impactor crankcase ventilator to reduce engine emissions in line with Euro
6 requirements and boost fuel efficiency [A]. This new component of diesel
filtration systems was awarded the prestigious Grand Prix prize at the
2012 British Engineering Excellence Awards: "An inventive engineering
solution that solves a significant environmental problem and which has
strong commercial drivers to a large potential market" [D].
This innovation based on research described in Section 2 has enabled the
company to secure a number of orders from major clients, thereby creating
80 new jobs [A]. The company has further used this new product to gain new
business from a key manufacturer in the agriculture and construction
machines sector. This contract, worth £1.5 million per year (2012-2017),
has led the company to appoint nine new employees to deliver the new
business [A]. The company has further stated that "the research is having
a major influence on the company's current strategy and growth plans; the
company expects that its engagement with Leeds will directly lead to a
further £3 million revenue per year by 2013/14, growing to £10 million per
year by 2015" [A].
Yorkshire Ambulance Service NHS Trust
The Yorkshire Ambulance Service (YAS) provides emergency services to
people across Yorkshire and their fleet of vehicles travel 40 million
kilometres each year. YAS has over 110 locations, 4500 staff and 1500
vehicles. Having participated in the Carbon Trust's Public Sector Carbon
Management programme in 2010, YAS drew up a Carbon Management Plan for
2011-2015. Taking 2007 as the baseline year when the carbon footprint was
16,531 tonnes of CO2, YAS decided to set a target of a 30%
reduction in carbon usage by 2015 with the added benefit of a cost saving
of £3.39 million.
Researchers in the UoA secured an EPSRC Knowledge Transfer Secondment
(EP/H500251/1) which allowed them to work with YAS in applying the
optimisation research described above to ambulance design in conjunction
with Computational Fluid Dynamics from the School of Mechanical
Engineering at Leeds (Thompson). Initial investigation led to a focus on
the light bars on the vehicle roof and this demonstrated that the drag
force could be reduced by up to 20% [E].
This optimised design was applicable to up to 60% of the YAS fleet which
was shown to equate to an annual £700,000 saving in fuel costs and an
annual reduction of 500 tCO2 [E].
Based on the results of the KTS YAS commissioned new ambulance designs
that came into operation in early July 2013 [E]. The new vehicles have
achieved 26 mpg compared to 16-18 mpg previously [E]. Given the figure of
40 million kilometres per year across the YAS fleet this equates to
significant potential savings. YAS state "in the first year of utilising
the new vehicles in part of the fleet YAS expect to save £300,000 in fuel"
along with the consequent CO2 reductions [E].
The research on optimisation outlined above has been implemented in the
Rolls-Royce SOFT optimisation system leading to its successful use during
the REF period "in live aeroengine design projects with tens of hours of
CPU time per simulation and over a hundred design variables" [F]. In this
way the research in the UoA has led to optimisation of designs that was
previously impossible due to prohibitive computational requirements [F].
Rolls-Royce states that the systems based on the UoA research "has been
successfully used for real-life optimisation of RR compressor blades (e.g.
the ESS (Engine Sector Stator blade) component of a high-bypass ratio
engine) and on the Trent turbine HP and IP stages that are being developed
in RR". Through using the MAM outlined in Section 2 Rolls-Royce have seen
a reduction in CPU time of an order of magnitude and significantly
improved performance in handling near equality constraints [F]. Ultimately
this has led to "0.15% efficiency improvements of critical components like
IP (Intermediate Pressure) Turbine stages of a modern high by-pass jet
engine" in the REF period [F].
Rolls-Royce has used the SOFT optimisation system on a number of other
design projects for turbomachinery. Whilst the Rolls-Royce system has a
range of optimisation techniques, Rolls-Royce states that "so far, MAM has
proved to be the most efficient and accurate of the optimisers where
expensive high fidelity CFD codes are used in the optimisation process"
[F] and that "overall MAM has been an order of magnitude faster than other
previously used techniques, this has reduced the optimisation time
significantly, and made MAM a practical design tool on a modest Linux
It is hard to put a financial figure to these benefits and Rolls-Royce do
not calculate such figures due to the uncertainties of operating
conditions and other variables. However, given that a commercial airline
spends billions of dollars per year on fuel [G], even a small efficiency
improvement leads to millions of dollars of cost savings.
Sources to corroborate the impact
A. Individual written corroboration (October 29th, 2013) from
Research and Development Manager, Parker Hannifin Manufacturing (UK) Ltd,
Filter Division Europe, Churwell Vale, Dewsbury, WF12 7RD.
B. Eves, J., Toropov, V.V., Thompson, H.M., Kapur, N, Fan, J., Copley, D.
and Mincher, A. Design optimization of supersonic jet pumps using high
fidelity flow analysis. Structural and Multidisciplinary Optimization, 45
(5): 739-745, 2012, DOI: 10.1007/s00158-011-0726-8.
C. Fan, J., Eves, J., Thompson, H.M., Toropov, V.V., Kapur, N., Copley,
D. and Mincher, A. Computational fluid dynamic analysis and optimization
of jet pumps. Computers and Fluids, 46: 212-217, 2011, DOI:
D. British Engineering Excellence Awards: http://www.beeas.co.uk/winners/beeas-2012-winners.pdf
(accessed August 28th, 2013; see page 3).
E. Individual written corroboration (October 17th, 2013) from
Environmental and Sustainability Manager, Yorkshire Ambulance Service NHS
Trust, Brunel Road, Wakefield 41 Business Park, Wakefield, WF2 0XG.
F. Individual written corroboration (October 24th) from
Engineering Associate Fellow — Aerothermal Design System, 3D Geometry,
Meshing and Optimisation Team Lead, Rolls Royce plc., Derby.
G. British Airways Annual Report and Accounts 2012:
(accessed August 28th, 2013, see page 6).