Engineering and the Environment

András Sóbester


Primary position:
Senior Lecturer


The University of Southampton
Dr András Sóbester's photo

"Using sophisticated optimization algorithms to engineer aircraft shapes the air likes to touch"

Dr. András Sóbester is a Senior Lecturer in Aeronautical Engineering. His research focus is on developing techniques for the aerodynamic optimization of aircraft (as distilled into the parahprase to the right by aircraft geometry pioneer E. Schmued), as well as on understanding and enhancing the potential of 3d printing in the aerospace design process.

Dr Sóbester leads the development of AirCONICS (Aircraft CONfiguration through Integrated Cross-disciplinary Scripting), a parametric geometry toolkit for aircraft conceptual design. A recently published Wiley textbook sets out the theoretical and practical foundations behind the parametric models implemented in AirCONICS.

Stratospheric flight (whether on fixed wings or balloon-borne), especially the design of high altitude Unmanned Air Vehicles (UAVs) for scientific applications, is another key area of interest. He leads the ASTRA (Atmospheric Science Through Robotic Aircraft) initiative, which aims to develop high altitude unmanned aircraft for meteorological and Earth science research.

Dr. Sóbester lectures on two modules on the University's Aeronautics and Astronautics course: Aircraft Operations and Mechanics of Flight (first year) and Aircraft Design (third year). He also supervises third and fourth year individual and group design projects.

Short biography...

Having obtained degrees in Mechanics and Mechanical Engineering (1st) and Design and Manufacture (1st), he joined the University of Southampton as a PhD student in 2000. Upon completion of his doctorate ("Enhancements to Global Design Optimization Techniques") he worked as a Research Fellow in the Computational Engineering and Design research group on a series of industrial research projects for Rolls-Royce and BAE Systems.

His appointment to an academic position in 2007 was followed by the award of a five year Royal Academy of Engineering (RAEng) Research Fellowship. András's RAEng research focused on reducing the environmental impact of passenger airliners through unconventional airframe geometries.

In addition to 20+ journal articles, András is the author of a book exploring the scientific and technological limits of flight at high altitudes, as well as co-author of two Wiley texts, one on the statistical modeling for engineering design applications, another on aircraft geometry.



The University of Southampton's electronic library (e-prints)


Sobester, Andras, Czerski, Helen and Zapponi, Niccolo et al. (2014) High Altitude Gas Balloon Trajectory Prediction - a Monte Carlo Model. AIAA Journal, 52, (4), 832-842. (doi:10.2514/1.J052900).
Sobester, Andras (2014) Four suggestions for better parametric geometries. 10th AIAA Multidisciplinary Design Optimization Conference, 1-10.
Marsh, R., Sobester, Andras, Hart, Elizabeth E., Oliver, K.I.C., Edwards, Neil and Cox, S.J. (2013) An optimally tuned ensemble of the "eb_go_gs" configuration of GENIE: parameter sensitivity and bifurcations in the Atlantic overturning circulation. Geoscientific Model Development, 6, 1729-1744. (doi:10.5194/gmd-6-1729-2013).
Sobester, Andras and Powell, Stephen (2013) Design space dimensionality reduction through physics-based geometry re-parameterization. Optimization and Engineering, 14, (1), 37-59. (doi:10.1007/s11081-012-9189-z).
Langmaak, Stephan, Wiseall, Stephen, Bru, Christophe, Adkins, Russell, Scanlan, James and Sóbester, András (2013) An activity-based-parametric hybrid cost model to estimate the unit cost of a novel gas turbine component. International Journal of Production Economics, 142, (1), 74-88. (doi:10.1016/j.ijpe.2012.09.020).
Powell, Stephen, Sobester, Andras and Joseph, Phillip F. (2012) Fan broadband noise shielding for over-wing engines. Journal of Sound and Vibration, 331, (23), 5054-5068. (doi:10.1016/j.jsv.2012.06.012).
Sobester, Andras, Forrester, Alexander I.J., Toal, David J.J., Tresidder, Es and Tucker, Simon (2012) Engineering design applications of surrogate-assisted optimization techniques. Optimization and Engineering, 15, (1), 243-265. (doi:10.1007/s11081-012-9199-x).
Li, Dong, Sobester, Andras and Keane, Andy J. (2012) Technical notes. Physics- and engineering knowledge-based repair of computer-aided design parametric geometries. AIAA Journal, 50, (6), 1409-1414. (doi:10.2514/1.58663).
Hart, E.E., Sobester, A., Djidjeli, K., Molinari, M., Thomas, K.S. and Cox, S.J. (2012) A geometry optimization framework for photonic crystal design. Photonics and Nanostructures - Fundamentals and Applications, 10, (1), 25-35. (doi:10.1016/j.photonics.2011.06.005).
Carrese, Robert, Winarto, Hadi, Li, Xiaodong, Sobester, Andras and Ebenezer, Samuel (2012) A comprehensive preference-based optimization framework with application to high-lift aerodynamic design. Engineering Optimization (In Press).
Tudose, Lucian, Stanescu, Cristina and Sobester, Andras (2011) Improving machine dynamics via geometry optimization. Structural and Multidisciplinary Optimization, 44, (4), 547-558. (doi:10.1007/s00158-011-0641-z).
Carrese, Robert, Sobester, Andras, Winarto, Hadi and Li, Xiaodong (2011) Swarm heuristic for identifying preferred solutions in surrogate-based multi-objective engineering design. AIAA Journal, 49, (7), 1437-1449. (doi:10.2514/1.J050819).
Tudose, Lucian , Buiga, Ovidiu, Ştefanache, Cornel and Sóbester, András (2010) Automated optimal design of a two-stage helical gear reducer. Structural and Multidisciplinary Optimization, 42, (3), 429-435. (doi:10.1007/s00158-010-0504-z).
Sóbester, András (2009) Concise airfoil representation via case-based knowledge capture. AIAA Journal, 47, (5), 1209-1218. (doi:10.2514/1.40119).
Sobester, A., Nair, P.B. and Keane, A.J. (2008) Genetic programming approaches for solving elliptic partial differential equations. IEEE Transactions on Evolutionary Computation, 12, (4), 469-478. (doi:10.1109/TEVC.2007.908467).
Forrester, Alexander I.J., Sóbester, András and Keane, Andy J. (2007) Multi-fidelity optimization via surrogate modelling. Proceedings of the Royal Society A, 463, (2088), 3251-3269. (doi:10.1098/rspa.2007.1900).
Sóbester, András (2007) Tradeoffs in jet inlet design: a historical perspective. Journal of Aircraft, 44, (3), 705-717. (doi:10.2514/1.26830).
Forrester, Alexander I.J., Sobester, Andras and Keane, Andy J. (2006) Optimization with missing data. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 462, (2067), 935-945. (doi:10.1098/rspa.2005.1608).
Sobester, A. and Keane, A.J. (2006) Supervised learning approach to parametric computer-aided design geometry repair. AIAA Journal, 44, (2), 282-289.
Sóbester, András, Leary, Stephen J. and Keane, Andy J. (2005) On the design of optimization strategies based on global response surface approximation models. Journal of Global Optimization, 33, (1), 31-59. (doi:10.1007/s10898-004-6733-1).
Sóbester, A., Leary, S.J. and Keane, A.J. (2004) A parallel updating scheme for approximating and optimizing high fidelity computer simulations. Structural and Multidisciplinary Optimization, 27, (5), 371-383. (doi:10.1007/s00158-004-0397-9).


Sobester, Andras (2011) Stratospheric Flight: Aeronautics at the Limit, New York, US, Springer, 215pp. (Praxis Books ).
Forrester, Alexander, Sobester, Andras and Keane, Andy (2008) Engineering design via surrogate modelling: a practical guide, Chichester, UK, Wiley, 228pp.

Book Section

Sóbester, A. and Keane, A.J. (2005) Classifier systems can reduce conceptual design cycle time. In, Proceedings of the 1st International Conference on Innovation and Integration in Aerospace Sciences. 1st International Conference on Innovation and Integration in Aerospace Sciences , American Institute of Aeronautics and Astronautics, 1-9.
Sóbester, András, Keane, A.J., Scanlan, James and Bressloff, Neil W. (2005) Conceptual design of UAV airframes using a generic geometry service. In, Infotech@Aerospace Online Proceedings. Infotech@Aerospace , American Institute of Aeronautics and Astronautics.
Sobester, Andras, Nair, P.B. and Keane, A.J. (2004) Evolving intervening variables for response surface approximations. In, Proceedings of the 10th AIAA/ISSMO multi-disciplinary analysis and optimization conference. Multidisciplinary Analysis and Optimization Conference , American Institute of Aeronautics and Astronautics, 1-12.
Sóbester, András and Keane, Andy J. (2002) Empirical comparisons of gradient-based methods on an engine-inlet shape optimization problem. In, Proceedings of the 9th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization. 9th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization Reston, USA, American Institute of Aeronautics and Astronautics.

Conference or Workshop Item

Sobester, Andras (2015) Self-designing parametric geometries. In, AIAA SciTech 56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Kissimmee, US, 05 - 09 Jan 2015. American Institute of Aeronautics and Astronautics8pp, 1-8. (doi:10.2514/6.2015-0396).
Paulson, Christopher, Sobester, Andras and Scanlan, James (2015) Rapid development of bespoke sensorcraft: a proposed design loop. In, AIAA SciTech 56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Kissimmee, US, 05 - 09 Jan 2015. American Institute of Aeronautics and Astronautics20pp. (doi:10.2514/6.2015-0135).
Kontogiannis, Konstantinos, Sobester, Andras, Taylor, Nigel, Aeronautics, Astronautics and Computational Engineering and Design Group and MBDA, Filton UK (2015) On the conceptual design of waverider forebody geometries. In, AIAA SciTech 56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Kissimmee, US, 05 - 09 Jan 2015. American Institute of Aeronautics and Astronautics10pp, 1-10. (doi:10.2514/6.2015-1009).
Crispin, Chris and Sobester, Andras (2015) An intelligent, heuristic path planner for multiple agent unmanned air systems. In, AIAA SciTech 56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Kissimmee, US, 05 - 09 Jan 2015. American Institute of Aeronautics and Astronautics13pp. (doi:10.2514/6.2015-0361).
King, Philip H., Scanlan, James, Sobester, Andras and Aeronautics, Astronautics and Computational Engineering and Design Group (2015) From radiosonde to papersonde: the use of conductive inkjet printing in the massive atmospheric volume instrumentation system (MAVIS) project. In, AIAA SciTech 56th AIAA/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Kissimmee, US, 05 - 09 Jan 2015. American Institute of Aeronautics and Astronautics9pp, 1-9. (doi:10.2514/6.2015-0985).
Kelly, Liam, Keane, Andy J., Sobester, Andras and Toal, David J.J. (2014) Topology optimisation: increasing the speed and reliability of design. In, 15th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, Atlanta, US, 16 - 20 Jun 2014. American Institute of Aeronautics and Astronautics11pp. (doi:10.2514/6.2014-2593).
Kelly, Liam, Keane, Andy J., Sobester, Andras and Toal, David J.J. (2013) Automated structural design of a UAV fuselage for manufacture by selective laser sintering. In, CNM2013: Congress on Numerical Methods in Engineering, Bilbao, ES, 25 - 28 Jun 2013. 20pp.
Sobester, Andras, Czerski, Helen, Zapponi, Niccolo and Castro, I.P. (2013) Notes on meteorological balloon mission planning. In, AIAA Balloon Systems (BAL) Conference, Daytona Beach, US, 26 - 28 Mar 2013. 15pp, 1-15. (doi:10.2514/6.2013-1295).
Paulson, Christopher and Sobester, Andras (2013) Parameterization and geometric optimization of balloon launched sensorcraft for atmospheric research missions. In, 51st AIAA Aerospace Sciences Meeting , Grapevine, US, 07 - 10 Jan 2013. 11pp.
Deshpande, A. S. , Keane, A.J., Sobester, Andras and Toal, David J.J. (2012) Geometric parameterisation of firtree joints in gas turbine discs considering manufacturing variability. In, 3rd Aircraft Structural Design Conference, Delft, NL, 09 - 12 Oct 2012.
Langmaak, Stephan, Scanlan, James P., Wiseall, Stephen and Sobester, Andras (2011) Strategic jet engine system design in light of uncertain fuel and carbon prices. In, 11th AIAA Aviation Technology, Integration, and Operations (ATIO) Conference, Virginia Beach, US, 20 - 22 Sep 2011. 16pp.
Powell, S., Sobester, A. and Joseph, P.F. (2011) Performance and noise trade-offs on a civil airliner with over-the-wing engines. In, 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, Orlando, US, 04 - 07 Jan 2011. 17pp.
Hart, Elizabeth, Sobester, Andras, Djidjeli, K., Molinari, Marc, Cox, Simon J. and Thomas, Ken S. (2010) Geometry optimization of photonic crystals. At Photon 10, Southampton, GB, 23 - 26 Aug 2010.
Li, D., Sobester, A. and Keane, A.J. (2010) A knowledge-based geometry repair system for robust parametric CAD models. In, 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, Orlando, Florida, 04 - 07 Jan 2010. 17pp, 1-17.
Sobester, Andras (2009) Notes on the connections between shape definition and the objective function landscape. In, 2nd International Conference on Advanced Engineering in Mechanical Systems (ADEMS' 09), Cluj-Napoca, Romania, 24 - 25 Sep 2009. 4pp.
Sobester, A. (2009) Exploiting patterns in the Kulfan transformations of supercritical airfoils. In, 9th AIAA Aviation Technology, Integration, and Operations Conference (ATIO), Hilton Head, USA, 21 - 23 Sep 2009. , 1-18.
Sóbester, András and Barrett, Thomas (2008) The quest for a truly parsimonious airfoil parameterisation scheme. In, ICAS 2008 Congress including the 8th AIAA 2008 ATIO Conference, Anchorage, USA, 14 - 19 Sep 2008. USA, American Institute of Aeronautics and Astronautics, 24pp.
Sobester, Andras and Keane, Andy J. (2007) Airfoil design via cubic splines - Ferguson's curves revisited. In, AIAA infotech@Aerospace 2007 Conference and Exhibit, Rohnert Park, USA, 07 - 10 May 2007. American Institute of Aeronautics and Astronautics15pp, 1-15.
Sobester, Andras and Keane, Andy J. (2006) Multi-objective optimal design of a fluidic thrust vectoring nozzle. In, 11th AIAA/ISSMO Multidisciplilnary Analysis and Optimization Conference, Portsmouth, USA, 06 - 08 Sep 2006. USA, American Institute of Aeronautics and Astronautics9pp.
Sobester, A. and Keane, A.J. (2006) Multidisciplinary design optimization of UAV airframes. In, 47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, Newport, Rhode Island, 01 - 04 May 2006. American Institute of Aeronautics and Astronautics13pp.
Scurr, A.D., Keane, A.J., Sobester, A., Gould, A. and Leary, S. (2003) A grid-based problem solving environment that uses the Master/Worker paradigm to parallelize DoE/RSM/Data-Fusion search computations. In, Fifth World Congress of Structural and Multidisciplinary Optimization (WCSMO-5), Venice, Italy, 19 - 23 May 2003. Milan, Italy, Schonenfeld and Ziegler31pp.
Sobester, A. and Keane, A.J. (2002) Empirical comparison of gradient-based methods on an engine-inlet shape optimization problem. In, 9th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization, Georgia, USA, 04 - 06 Sep 2002. 11pp.


Sobester, A. (2003) Enhancements to global design optimization techniques. University of Southampton, School of Engineering Sciences, Doctoral Thesis .


Research Interests

  • Design optimization (global and local search techniques)
  • Aircraft design
  • Unmanned air vehicles, in particular their use in science missions
  • Rapid prototyping methods in aerospace engineering
  • High altitude flight
  • Aerodynamic shape optimization
  • Shape parameterization, geometry dimensionality reduction methods
  • Surrogate modelling and optimization methods based on surrogate update schemes
  • Design technologies
  • Expert systems
  • Climate model tuning
The ASTRA initiative…

…investigates new technologies for making low cost observations of the physical parameters of the atmosphere. ASTRA develops and tests platforms capable of delivering scientific instruments to altitudes ranging from the planetary boundary layer (hundreds of meters) to the upper stratosphere (up to 50km).

A key research thrust here is the introduction of new developments in rapid multi-disciplinary design and rapid prototyping into atmospheric platform design, enabling the production of highly bespoke, high performance vehicles around a given payload and mission.

With platform development cycles reduced to weeks, instrument development and deployment can also be accelerated, enabling faster experimental cycles, more rapid deployment and lower operating costs.

A related research interest is the design of stratospheric fixed wing aircraft, in particular of balloon-launched unmanned vehicles. On their own, or as part of a swarm, such aircraft represent a low cost and effective means of sampling pollutant concentrations or other parameters in large blocks of the upper atmosphere.

Aircraft Geometry

As part of a Royal Academy-funded Research Fellowship Dr Sóbester investigated novel formulations for the mathematical representation of aircraft external surfaces, as well as for the most efficient use of physics-based performance analyses of the resulting aircraft. The goal of this (ongoing) work is to facilitate multi-disciplinary design optimization studies, which enable the development of high performance aircraft with low environmental impact.

The study included an application of such technologies, centred around reducing environmental noise in communities living under the departure paths of airports by shaping airframe geometries such that they reflect engine noise upwards, away from residential areas.

Surrogate Modelling and Knowledge Capture

A surrogate model is a mathematical formulation used to capture salient information from expensive and/or sparse data (obtained experimentally or through computer simulations). Dr. Sóbester’s work over the last decade has encompassed a number of areas of application for such technologies, ranging from machine learning systems designed to capture physics- or geometry-based knowledge related to an aerospace system to frameworks designed to accelerate the tuning of computational climate models.



Balloon-borne stratospheric instrument platform demonstrating rapid prototyping technologies


Lowering environmental impact

Unconventional airframe geometries for fan noise shielding

Lowering environmental impact

Surrogate modelling technology

Global sea ice extent, as predicted by a numerical climate simulation

Surrogate modelling technology

Balloon-launched glider

One of ASTRA’s goals is to improve access to extreme altitudes

Balloon-launched glider

Primary research group:  Computational Engineering and Design

PhD students


Mr Christopher Paulson

Chris is investigating the place of additive manufacturing techniques in the development process of small unmanned aircraft. Technologies such as Selective Laser Sintering (SLS) have the potential to speed up the development process by becoming an integral part of the Multi-Disciplinary Design Optimization process through the ability to create several flying prototypes through the process. These iterations, which thus augment the the computational analysis through flight test data, will lead to a better final design, which, in some cases, can be a 3d printed air vehicle itself.

Mr Christopher Crispin

One of the goals of the ASTRA initiative is to develop a Massive Atmospheric Volume Instrumentation System (MAVIS). At the centre of MAVIS lies a novel concept for an atmospheric sensing system: a fleet of small, very light, instrumented gliders are released en masse from a high altitude meteorological balloon over the environment to be observed. During their autopilot-guided descent along paths optimized for sampling efficiency, they collect a dense set of readings, which can subsequently be converted into an accurate map of the quantity (e.g., pollutant concentration) being observed. Chris Crispin is looking into how to optimize the efficiency of the sampling through evolving efficient autopilot algrithms for the individual aircraft, as well as exploiting any emerging behaviour exhibited by the glider swarm.

Past (graduated)

Dr Stephen Powell

Stephen tackled a complex multi-disciplinary design optimization problem: that of finding the optimum locations of gas turbine engine nacelles mounted above the wings of an A320/B737-scale commercial airliner. Such an installation has numerous advantages. It permits very high bypass ratios, reduces the risk of ingesting foreign objects on take-off, etc. The greatest advantage, however, is that it mitigates the noise nuisance on communities on the ground by virtue of the airframe reflecting the much of the broadband fan noise upward, away from the ground. The key challenge here was to come up with effective and efficient ways of combining physics-based computational analyses (computational fluid dynamics) and physical experiments (acoustic scale model measurements) into a single design framework.

Dr Dong Li

Dong's work was centred around the idea of using machine learning techniques to capture - and later deploy - design knowledge in the context of automated parageometry generation for multi-disciplinary design optimization processes. Dong used support vector regression to create models of geometry plausibility, which were then used to increase the efficiency of the search for the optimal design by steering the optimizer away from areas where the resulting design would be likely to fail.

Co-Supervised (current)

Mr. Aditya Deshpande

Manufacturing uncertainty quantification in the context of the design and manufacture of gas turbine engine turbine blades. Lead supervisor Prof Andy J Keane.

Mr. Liam Kelly

Automated design of complex structural components using topology optimization techniques. Lead supervisor Prof Andy J Keane.

Ms. Giang Tran

Bayesian data fusion techniques (in particular Co-Kriging-type emulators) in Earth System modeling. Lead supervisor Dr Kevin Oliver (School of Ocean and Earth Sciences).

Mr. Stephan Langmaak

Activity-based parametric cost models with applications in gas turbine engine design. Lead supervisor Prof James Scanlan.

New ways to build an aircraft win a prize

An innovative proposal to design an aircraft by computer and produce it through 3D printing has won an Engineering PhD student a £3,000 prize.

Find out more

Paulson: 3d printing in UAV design

Investigating the potential of additive manufacturing in the development of UAVs

Paulson: 3d printing in UAV design

Noise deflection experiments

Stephen Powell's PhD considered the noise reduction potential of installing engines above the wings of airliners

Noise deflection experiments


Aircraft Operations and Mechanics of Flight (first year, module leader)

This part one specialist module covers topics such as air law, airline economics, air safety, the regulatory bodies of aviation, aviation weather and airport design in the first semester. In the second semester the fundamentals of flight mechanics are introduced, with an opportunity for the students to experience some fundamental phenomena in the University's flight simulator.

Aircraft Design (third year, module leader)

This is a synthesis module, which pulls together a number of aircraft engineering science topics studied in years 1 and 2 (mechanics of flight, fluid dynamics, wing aerodynamics, structures, design, etc.) and gives student teams the opportunity to undertake their first real aircraft design exercise.

A Flying Laboratory Course, a one week series of lectures and test flights undertaken on board the National Flying Laboratory (G-NFLA), is also part of this module and it is an exciting opportunity for students to experience some key phenomena related the static and dynamic stability of aircraft on board this specially instrumented turboprop (see sidebar for images).

Atmospheric Science UAV - Group Design Project (fourth year, supervisor)

Typically constructed around a real science mission, this GDP challenges a group of fourth year students to design, build and flight test an unmanned air system capable of collecting measurements in the atmosphere.

Oceanographic UAV

Balloon-launched glider/drifter built by fourth year GDP students.

Oceanographic UAV

Students on board

Students on board

Disembarking from G-NFLA

Disembarking from G-NFLA

Part 3 Aircraft Design - flying laboratory course

Part 3 Aircraft Design - flying laboratory course

The National Flying Laboratory on final approach into Southampton Airport

The National Flying Laboratory on final approach into Southampton Airport


Dr András Sóbester
Computational Engineering and Design Group Engineering Centre of Excellence Building 176 University of Southampton Boldrewood Campus Burgess Road Southampton SO16 7QF

Room Number: 176/5005