1. Recent developments in the CEASIOM framework using the common language CPACS
Good afternoon, my name is Marco Cristofaro and the work that I will present is part of my master thesis, it is based on a collaborative activity work for the CEASIOM software development with other European students doing their master thesis as well.
Marco Cristofaro
Da Ronch A., Rizzi A., Vos J.
Master thesis
University of Southampton and Politecnico di Torino
4th EASN Workshop on Flight Physics and Aircraft Design
Aachen (DE) - 15 October 2014

2. Work objective Efficient flight dynamics analysis S&C during
conceptual aircraft
design phase
(limited budget)
Nonlinear
aerodynamic
CFD fidelity
The target of my work was to obtain a method for the flight dynamics analysis more efficient.
Non linear aerodynamics phenomena as shocks or boundary layer separation
->require CFD techniques to create physical based model of the system
-> my work focused on the introduction of these methods for the Stability and Control analysis during the conceptual aircraft design phase.
-> to limit the budget, it is necessary to have automatic mesh generation tools and methods to create the aerodynamic tables at a reduced cost that can be used inside a flight simulator.
The obtained results can be then used in an optimization loop of the geometry that aim to obtain better S&C aircraft characteristics.
Aerodynamic table (~1million flight points)
at reduced cost
Automatic mesh generation
Traditional
flight simulators
Geometry optimization
for flight dynamics

3. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
This is the structure of the presentation. In

4. Aircraft conceptual design and CEASIOM
Conceptual design:
Today
Handbook method
Linear mechanics hypothesis
Future
High fidelity
Virtual flight simulation
Scharl, J., Mavris, D.N., Burdun, I.Y., “Use of Flight Simulation in Early Design: Formulation and Application of the
Virtual Testing and Evaluation Methodology ,” 2000 World Aviation Conference, San Diego, CA

5. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
During the first design phases, highlighted in red, the choices strongly influence the overall project cost BUT the knowledge are limited.
Semi-empirical and statistical methods are usually adopted.
The exploitation of physical based models would allow high fidelity flight simulations,
increasing the knowledge and so reducing the cost committed avoiding costly retro-fitting
I partecipated to the development and validation of some new methods in the software CEASIOM
This program is freely available online and it encloses different modules representing the different aircraft design disciplines.
3 partner Soton, CFS Engineering Losanna, KTH Stoccolma and aims to help designer during the first aircraft design phases.
(Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods)

6. Geometry definition CPACS Old CEASIOM vs unlimited parameters
Software update: new version use the CPACS file design scheme.
PRO: it allows non traditional configs
increasing accuracy level with the design steps
common format for softwares data exchanging
Rizzi, A., Zhang, M., Nagel, B., Boehnke, D., and Saquet, P., “Towards a Unified Framework using CPACS for Geometry
Management in Aircraft Design,” 50th AIAA Aerospace Sciences Meeting, Nashville, Tennessee, USA, January 2012.

7. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions

8. DATCOM USAF S&C Digital Compendium
converted to
~20 conventional
parameters
complex geometry
parameters
Aerodynamic module upgrade
First we integrated DATCOM. (Developed during the ’70 by united states air force, today it is a open program to compute the aerodynamic data of a traditional configuration starting from the statistical data)
The problem was to use the complex CPACS geometry definition in DATCOM. It we generated a method to extract around 20 parameters that describe the main geometrical characteristics.
-> Accurate results for the lift although the stall is not predicted

9. Edge FOI unstructured CFD solver
defined external geometry
SUrface MOdeller
Unstructured surface grid
Triangular
using of Chew’s algorithm
Unstructured volume mesh
Filling with TetGen
quality Delaunay tetrahedral mesh generator
Si, H., “TetGen: a quality tetrahedral mesh generator
and 3D delaunay triangulator,” WIAS technical Report No. 13, 2013.
Integration of the CFD solver Edge. It is developed by the Swedish defense agency and a limited version to non-viscous and one processor computations is freely downloadable online.
SUMO can be used as a tool for the mesh generation inside CEASIOM and can generate an autonomous process.
-> Results show an accurate CLalpha trend, but the CL0 difference might be caused by differences in the geometrical model (delta S), the stall position is well acquired but its intensity is underestimated
Structured grids are identified by regular connectivity.
Unstructured grids
Pattern (schema) non regolare, by irregular connectivity. It cannot easily be expressed as a two-dimensional or three-dimensional arrays in computer memory.

10. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
During the first design phases, highlighted in red, the choices strongly influence the overall project cost BUT the knowledge are limited.
Semi-empirical and statistical methods are usually adopted.
The exploitation of physical based models would allow high fidelity flight simulations,
increasing the knowledge and so reducing the cost committed avoiding costly retro-fitting
I partecipated to the development and validation of some new methods in the software CEASIOM
This program is freely available online and it encloses different modules representing the different aircraft design disciplines.
3 partner Soton, CFS Engineering Losanna, KTH Stoccolma and aims to help designer during the first aircraft design phases.
(Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods)

11. Sampling procedure Kriging interpolation model
target & predicted
functions
predicted & real
errors
Lift
Video presenta processo campionamento tramite CFD x valutazione delle caratt aero con interpolazione dei dati disponibili. Portanza, resistenza, momento lineari inizio -> interesse a concentrare calcoli dove nonlinear
Drag
Pitching moment

12. Cognitive sampling methods
lift like function
Off-the-shelf methods (max EIF):
Inability to capture local nonlinearities
Large number of samples for convergence
Uniform samples distribution 𝜖r≃0.404%
MAXmin samples 𝜖r≃0.265%
Cognitive sampling development
The target was to create a method able to efficiently choose the samples position. Current methods based on the estimated interpolation error generate a uniform distribution. They can be really expensive and reducing the budget they may not capture the nonlinearity appearing in the functon. This methods should neglect the linear part of the functions and focus on the nonlinearities.
-> The first method is based on the evaluation of local MAXmin.
The second estimate the function curvature or Hessian Matrix approximation -> both the methods halved the interpolated function error compared wrt the target function
Developed methods:
Local maxima and minima of the
function prediction search
Second derivative (Hessian matrix) of the
function prediction estimation
samples

13. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
During the first design phases, highlighted in red, the choices strongly influence the overall project cost BUT the knowledge are limited.
Semi-empirical and statistical methods are usually adopted.
The exploitation of physical based models would allow high fidelity flight simulations,
increasing the knowledge and so reducing the cost committed avoiding costly retro-fitting
I partecipated to the development and validation of some new methods in the software CEASIOM
This program is freely available online and it encloses different modules representing the different aircraft design disciplines.
3 partner Soton, CFS Engineering Losanna, KTH Stoccolma and aims to help designer during the first aircraft design phases.
(Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods)

14. Cognitive sampling validation
UCAV
TCR
𝜖r≃2.40%
𝜖r≃13.12%
MAXmin based
Hessian based
Methods validation:
The continous line was obtained with intensive WT experiment, but what if we had a limited computational time. With a uniform samples distribution the nonlinearity may not be but with the MAXmin method only 13 samples are necessary to obtain a good prediction of the unstable behavious and the plateau.
We aim to predict the aero performances with a few high cost computations. A uniform distribution may miss the nonlinearity. Considering the Unmanned Combact Air Vehicle: pitching moment changing the incidence. At around 17 degrees of AoA a strong but narrow nonlinearity appears for the leading edge vortices interaction.
A uniform distribution may not capture this strong nonlinearity and not focus close to it.
Transonic Cruiser: pitching moment changing incidence and sideslip angles
-> with only a few iterations we can obtain a full multi dimensional aero table at a reduced cost focusing on the possible non linearity appearing in the flow field
M = 0.12
Re =
M = 0.17
Re =
Rizzi, A., Eliasson, P., Goetzendorf-Grabowski, T., Vos, J. B.,
Mengmeng, Z., and Richardson, T. S.,
“Design of a canard configured TransCruiser using CEASIOM,”
Progress in Aerospace Sciences, Vol. 47, No. 8, 2011, pp. 695–705.
Vallespin, D., Da Ronch, A., Badcock, K. J., and Boelens, O.,
“Vortical Flow Prediction Validation for an Unmanned Combat Air Vehicle Model,”
Journal of Aircraft, Vol. 48, No. 6, 2011, pp. 1948–1959.

15. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
During the first design phases, highlighted in red, the choices strongly influence the overall project cost BUT the knowledge are limited.
Semi-empirical and statistical methods are usually adopted.
The exploitation of physical based models would allow high fidelity flight simulations,
increasing the knowledge and so reducing the cost committed avoiding costly retro-fitting
I partecipated to the development and validation of some new methods in the software CEASIOM
This program is freely available online and it encloses different modules representing the different aircraft design disciplines.
3 partner Soton, CFS Engineering Losanna, KTH Stoccolma and aims to help designer during the first aircraft design phases.
(Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods)

16. Regional Jet DNW Wind tunnel 1:23 model CAD model
Unstructured volume mesh
of 400,000 points
DNW Wind tunnel
1:23 model
CAD model
Design requirements:
Mass and inertia Howe’s evaluations:
Mission specifications:
Geometrical model:
CEASIOM capabilities for a test case.
This slide presents the main design parameters of the studied testcase
Starting from the CAD model -> a wind tunnel model and a mesh with SUMO were generated
Cristofaro, M., Wang, Y., and Da Ronch, A., ”Towards computational flight dynamics of a passenger jet aircraft,”
ICAS International Council of Aeronautical Sciences Conference, St Petersburg, Russia, Vol. 0462, September 2014, DOI: /

17. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
During the first design phases, highlighted in red, the choices strongly influence the overall project cost BUT the knowledge are limited.
Semi-empirical and statistical methods are usually adopted.
The exploitation of physical based models would allow high fidelity flight simulations,
increasing the knowledge and so reducing the cost committed avoiding costly retro-fitting
I partecipated to the development and validation of some new methods in the software CEASIOM
This program is freely available online and it encloses different modules representing the different aircraft design disciplines.
3 partner Soton, CFS Engineering Losanna, KTH Stoccolma and aims to help designer during the first aircraft design phases.
(Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods)

18. Aerodynamic data validationWT
DATCOM
VLM (Tornado)
CFD (Edge)
Reynold 4 106
Aerodynamic data validation with reference to the WT data. The results in terms of lift, drag and pitching moment are presented for the statistical method DATCOM, a panel method and a CFD solver.
CFD Edge: very good results for the drag (the constant gap is due to the viscous drag) & it is the only one to correctly compute the stall position for lift and pitching moment.
Very different results are instead obtained with the panel method.
(non viscous)
Mach 0.5 at 39,000 ft (147 m/s wrt ISA)

19. ROM for aero-tables generation
Kriging interpolation
of the CFD solutions
Data fusion
of DATCOM and CFD
Computations distribution
Aerodynamic tables:
Per analisi stabilità tabelle aerodinamiche complete
Dx struttura tabelle aerodinamiche in CEASIOM: “x” rappresenta che vengono inserite tutte le combinazioni dei valori considerati x quei parametri (però 10,530 punti inviluppo volo)
Sx Distribuzione delle soluzioni calcolate nel dominio (𝛼, M)
Utilizzo modelli interpolazione x calcolo del dominio completo
Tecniche fusione di due database aero x ottenerne uno più accurato dei due presi singolarmente
97 CFD computations
→ data density: 5% of (𝛼, M, β)

20. ROM for aero-tables generation
Kriging interpolation
of the CFD solutions
Data fusion
of DATCOM and CFD
Full aerodynamic table are necessary for the stability and control analyses.
The numer of entries can be very high, for exapmle if we consider a table with 3 rates, 3 control surfaces and alpha, M, beta for any of which 10 values are taken, the number of total entries would be10^9.
This table can be however obtained with Kriging interpolation methods starting from a few CFD samples.
For low speed the trend is linear for low incidence and then presents a trend variation for the stall appearance. For highMach numbers the shockwave appearance causes different results.
Databases combination techniques allows to fuse one high-fidelity and one low-fidelity databases, surprisingly obtaining one even better, taking advantage of the higher results density of the low fidelity database.
97 CFD computations
→ data density: 5% of (𝛼, M, β)

21. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
During the first design phases, highlighted in red, the choices strongly influence the overall project cost BUT the knowledge are limited.
Semi-empirical and statistical methods are usually adopted.
The exploitation of physical based models would allow high fidelity flight simulations,
increasing the knowledge and so reducing the cost committed avoiding costly retro-fitting
I partecipated to the development and validation of some new methods in the software CEASIOM
This program is freely available online and it encloses different modules representing the different aircraft design disciplines.
3 partner Soton, CFS Engineering Losanna, KTH Stoccolma and aims to help designer during the first aircraft design phases.
(Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods)

22. Longitudinal stability
Trim analysis
Dynamic stability
Angle of attack
Phugoid
Longitudinal stability analyses with different aerodynamic model -> trim e flight dynamical modes
The panel method is the only presenting a positive elevator deflection to trim the aircraft (because of the higher pitching mpment) e le caratteristiche dei modi longitudinali cade al di fuori della circonferenza che indica dove ci si aspetta il risultato reale possa trovarsi.
Elevator deflection
Short period

23. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
During the first design phases, highlighted in red, the choices strongly influence the overall project cost BUT the knowledge are limited.
Semi-empirical and statistical methods are usually adopted.
The exploitation of physical based models would allow high fidelity flight simulations,
increasing the knowledge and so reducing the cost committed avoiding costly retro-fitting
I partecipated to the development and validation of some new methods in the software CEASIOM
This program is freely available online and it encloses different modules representing the different aircraft design disciplines.
3 partner Soton, CFS Engineering Losanna, KTH Stoccolma and aims to help designer during the first aircraft design phases.
(Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods)

24. Geometry variations stability effect
Trim analysis
W&B estimation: handbook methods
Aerodynamic tables: data fusion + 18 CFD computations per configuration
Angle of attack
Short period
longitudinal mode
Considerate diverse geometrie variando rapporto di aspetto e freccia dell’ala. Per ognuna sono stati effettuati 18 calcoli CFD utilizzati con il metodo di fusione dei dati della configurazione base and W&B estimation. Only 2 weeks were necessary to compare the different configurations
Angolo freccia parametro più influente per il trim e i modi longitudinali
Elevator deflection

26. Rae2822 drag minimization minimize CD Result: 𝛼=-2.87° Mach 0.75
(V∞=225 m/s at s.l. wrt ISA)
Funzione ottenuta da dati sperimentali, e quindi di sua natura discreta.
Utilizzo alternativo di metodi di interpolazione di Kriging per ottenere un metodo basato sulla ricostruzione della risposta del sistema
Result:
𝛼=-2.87°

27. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
During the first design phases, highlighted in red, the choices strongly influence the overall project cost BUT the knowledge are limited.
Semi-empirical and statistical methods are usually adopted.
The exploitation of physical based models would allow high fidelity flight simulations,
increasing the knowledge and so reducing the cost committed avoiding costly retro-fitting
I partecipated to the development and validation of some new methods in the software CEASIOM
This program is freely available online and it encloses different modules representing the different aircraft design disciplines.
3 partner Soton, CFS Engineering Losanna, KTH Stoccolma and aims to help designer during the first aircraft design phases.
(Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods)

28. Geometry optimization loop
optimize stability
geometry
subject to feasible
Il test case del regional jet rappresenta un passo all’interno di un ciclo di ottimizzazione che miri a trovare la geometria tale da ottimizzare le caratteristiche di stabilità del velivolo. Esempio semplice è la ricerca del miglior angolo di freccia tale da minimizzare la resistenza aerodinamica in condizioni di trim
e.g.
minimize CDTRIM Λ
subject to -90°≤ Λ ≤ 90°

29. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
During the first design phases, highlighted in red, the choices strongly influence the overall project cost BUT the knowledge are limited.
Semi-empirical and statistical methods are usually adopted.
The exploitation of physical based models would allow high fidelity flight simulations,
increasing the knowledge and so reducing the cost committed avoiding costly retro-fitting
I partecipated to the development and validation of some new methods in the software CEASIOM
This program is freely available online and it encloses different modules representing the different aircraft design disciplines.
3 partner Soton, CFS Engineering Losanna, KTH Stoccolma and aims to help designer during the first aircraft design phases.
(Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods)

30. Strut-braced wing aircraft
Jungo A., CFSE under Vos J.
The work until here presented was done inside the European students team that upgraded CEASIOM. The introduced CPACS format allowed to use CEASIOM for a full design cycle of non traditional configurations.
Instead of a traditional cantilever wing -> High fuselage mounted wing and strut links fuselage and wing -> useful for tensile and compression stresses, although buckling phenomena may appear. So telescoping mechanism.
The strut permits higher AR wings so that the induced drag is reduced
The viscous drag increase for the new structural part, is overcome by the wing thickness and chord reduction, furthermore reducing the wave drag.
Jungo, A., Development of the CEASIOM aircraft design enviroment for novel aircraft configurations,
Master’s thesis, Ecole polytechnique federale de Lausanne, 2014.

31. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
During the first design phases, highlighted in red, the choices strongly influence the overall project cost BUT the knowledge are limited.
Semi-empirical and statistical methods are usually adopted.
The exploitation of physical based models would allow high fidelity flight simulations,
increasing the knowledge and so reducing the cost committed avoiding costly retro-fitting
I partecipated to the development and validation of some new methods in the software CEASIOM
This program is freely available online and it encloses different modules representing the different aircraft design disciplines.
3 partner Soton, CFS Engineering Losanna, KTH Stoccolma and aims to help designer during the first aircraft design phases.
(Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods)

32. Blended wing body aircraft
Martinez R. M., KTH under Rizzi A.
pr Reduced wetted area to volume ratio to obtain higher aerodynamic efficiency
reduced wing loading and deformation
vs difficult stability and controllability
Shock wave generation for high thickness, pressurization problem
Roberto, M. M., Design and Analysis of the Control and Stability of a Blended Wing Body Aircraft,
Master’s thesis, Royal Institute of Technology, Stockholm, 2014.

33. CPACS based CEASIOM 1. Work objective
2. Aircraft conceptual design and CEASIOM
2.1 New file scheme
2.2 Aerodynamic module upgrade
3. Cognitive sampling development
3.1Validation
4. Regional Jet test case
4.1 Aerodynamic data validation
4.2 Stability analysis
4.3 Geometry variations
5. Geometry optimization considering aircraft stability
5.1 Loop definition
6. Alternative aircraft configurations
6.1 Strut-braced wing aircraft
6.2 Blended wing body aircraft
7. Conclusions
During the first design phases, highlighted in red, the choices strongly influence the overall project cost BUT the knowledge are limited.
Semi-empirical and statistical methods are usually adopted.
The exploitation of physical based models would allow high fidelity flight simulations,
increasing the knowledge and so reducing the cost committed avoiding costly retro-fitting
I partecipated to the development and validation of some new methods in the software CEASIOM
This program is freely available online and it encloses different modules representing the different aircraft design disciplines.
3 partner Soton, CFS Engineering Losanna, KTH Stoccolma and aims to help designer during the first aircraft design phases.
(Computerised Environment for Aircraft Synthesis and Integrated Optimisation Methods)

34. Conclusions and future work
CEASIOM upgrade for CPACS format.
Cognitive sampling methods.
Geometry optimization considering aircraft S&C.
To summarize:
First the CEASIOM software was upgraded to the common CPACS format and all the aerodynamic methods are now integrated for the new file scheme.
Then we developed sampling methods to obtain more efficient results than off-the-shelf algorithms. They aim to concentrate the attention close to local nonlinearities, allowing to create a more accurate model with expensive computations.
The future work is to create an autonoumous process as for the regional jet test case, that aims to optimize the geometry not considering only the drag but also the S&C aircraft characteristics.