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Alfredson, J., Johansson, B., Gonzaga Trabasso, L., Schminder, J., Granlund, R. & Gårdhagen, R. (2018). DESIGN OF A DISTRIBUTED HUMAN FACTORS LABORATORY FOR FUTURE AIRSYSTEMS. In: ICAS congress proceeding: . Paper presented at 31st Congress of the International Council of the Aeronautical Sciences,Belo Horizonte, Brazil, September 9-14, 2018. International Council of the Aeronautical Sciences, Article ID ICAS2018_0305.
Open this publication in new window or tab >>DESIGN OF A DISTRIBUTED HUMAN FACTORS LABORATORY FOR FUTURE AIRSYSTEMS
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2018 (English)In: ICAS congress proceeding, International Council of the Aeronautical Sciences , 2018, article id ICAS2018_0305Conference paper, Published paper (Other academic)
Abstract [en]

This paper presents a rationale for structuring a distributed human factors laboratory for future air systems. The distributed herein refers to two aspects: content and geographic. As for content, the laboratory is structured in two levels, namely, individual, and team. As for geographic, the laboratory infrastructure is distributed in three physically separate facilities, namely, Department of Computer and Information Science (IDA) and Department of Management and Engineering (IEI) from Linköping University – Sweden and the Competence Center in Manufacturing from the Aeronautics Institute of Technology (ITA) – Brazil.

Place, publisher, year, edition, pages
International Council of the Aeronautical Sciences, 2018
Keywords
Human Factors; Future Air Systems; Laboratory
National Category
Computer and Information Sciences
Identifiers
urn:nbn:se:liu:diva-152898 (URN)978-3-932182-88-4 (ISBN)
Conference
31st Congress of the International Council of the Aeronautical Sciences,Belo Horizonte, Brazil, September 9-14, 2018
Available from: 2018-11-27 Created: 2018-11-27 Last updated: 2018-11-27
Hällqvist, R., Schminder, J., Eek, M., Braun, R., Gårdhagen, R. & Krus, P. (2018). NOVEL FMI AND TLM-BASED DESKTOP SIMULATOR FORDETAILED STUDIES OF THERMAL PILOT COMFORT. In: ICAS congress proceeding: . Paper presented at 31st Congress of the International Council of the Aeronautical Sciences,Belo Horizonte, Brazil, September 9-14, 2018. International Council of the Aeronautical Sciences, Article ID ICAS2018_0203.
Open this publication in new window or tab >>NOVEL FMI AND TLM-BASED DESKTOP SIMULATOR FORDETAILED STUDIES OF THERMAL PILOT COMFORT
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2018 (English)In: ICAS congress proceeding, International Council of the Aeronautical Sciences , 2018, article id ICAS2018_0203Conference paper, Published paper (Other academic)
Abstract [en]

Modelling and Simulation is key in aircraft systemdevelopment. This paper presents a novel,multi-purpose, desktop simulator that can beused for detailed studies of the overall performanceof coupled sub-systems, preliminary controldesign, and multidisciplinary optimization.Here, interoperability between industrially relevanttools for model development and simulationis established via the Functional MockupInterface (FMI) and System Structure andParametrization (SSP) standards. Robust anddistributed simulation is enabled via the TransmissionLine element Method (TLM). The advantagesof the presented simulator are demonstratedvia an industrially relevant use-case wheresimulations of pilot thermal comfort are coupledto Environmental Control System (ECS) steadystateand transient performance.

Place, publisher, year, edition, pages
International Council of the Aeronautical Sciences, 2018
Keywords
OMSimulator; FMI; TLM; Pilot Thermal Comfort; Modelling and Simulation
National Category
Applied Mechanics Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:liu:diva-152897 (URN)978-3-932182-88-4 (ISBN)
Conference
31st Congress of the International Council of the Aeronautical Sciences,Belo Horizonte, Brazil, September 9-14, 2018
Available from: 2018-11-27 Created: 2018-11-27 Last updated: 2018-11-27
Schminder, J., Hällqvist, R., Eek, M. & Gårdhagen, R. (2018). PILOT PERFORMANCE AND HEAT STRESS ASSESSMENTSUPPORT USING A COCKPIT THERMOREGULATORYSIMULATION MODEL. In: ICAS congress proceeding: . Paper presented at 31st Congress of the International Council of the Aeronautical Sciences,Belo Horizonte, Brazil, September 9-14, 2018. International Council of the Aeronautical Sciences, Article ID ICAS2018_0463.
Open this publication in new window or tab >>PILOT PERFORMANCE AND HEAT STRESS ASSESSMENTSUPPORT USING A COCKPIT THERMOREGULATORYSIMULATION MODEL
2018 (English)In: ICAS congress proceeding, International Council of the Aeronautical Sciences , 2018, article id ICAS2018_0463Conference paper, Published paper (Other academic)
Abstract [en]

Flights with high thermal loads inside the cockpitcan have a considerable impact on pilot physiologicaland psychological performance resultingin thermal discomfort, dehydration and fatigue.In this work, a Functional Mock-up Interface(FMI) based aircraft system simulator is utilizedwith intent to compute and predict thermalcomfort. The simulator can for example serve pilotsas a tool for heat stress and flight risk assessment,supporting their pre-flight planning or beused by engineers to design and optimize coolingefficiency during an early aircraft design phase.Furthermore, the presented simulator offers severaladvantages such as map based thermal comfortanalysis for a complete flight envelop, timeresolved mental performance prediction, and aflexible composability of the included models.

Place, publisher, year, edition, pages
International Council of the Aeronautical Sciences, 2018
Keywords
Thermal Comfort; Heat Stress;Thermoregulatory Model;Modeling and Simulation
National Category
Aerospace Engineering
Identifiers
urn:nbn:se:liu:diva-152900 (URN)978-3-932182-88-4 (ISBN)
Conference
31st Congress of the International Council of the Aeronautical Sciences,Belo Horizonte, Brazil, September 9-14, 2018
Available from: 2018-11-27 Created: 2018-11-27 Last updated: 2018-11-27
Schminder, J., Gårdhagen, R., Nilsson, E., Storck, K. & Karlsson, M. (2016). Development of a Cockpit-Pilot Model for Thermal Comfort Optimization During Long-Mission Flight. In: AIAA Modeling and Simulation Technologies Conference San Diego, California, USA: . Paper presented at SciTech 2016,AIAA Modeling and Simulation Technologies Conference San Diego, California, USA. AAAI Press
Open this publication in new window or tab >>Development of a Cockpit-Pilot Model for Thermal Comfort Optimization During Long-Mission Flight
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2016 (English)In: AIAA Modeling and Simulation Technologies Conference San Diego, California, USA, AAAI Press, 2016Conference paper, Published paper (Refereed)
Abstract [en]

The thermal comfort of a pilot is of crucial importance to maintain a high level ofconcentration and awareness during the entire ight mission. In this work a model for thethermal environment of the cockpit is developed and used as provider of input parametersto a thermoregulatory model, adopted from the literature, of a human. The cockpit-pilotmodel will be used to investigate and improve the thermal comfort for the pilot, particularlyduring longer ight missions. In the cockpit model a combination of lumped systems and nite dierence calculationsis used to obtain input parameters, which are provided to the pilot model. The body, withclothes, is divided into 16 segments and a nite dierence method is used to determine thetemperature distribution within these. Several physiological mechanisms are included inthe model. Simulations with dierent boundary conditions show that the models work properlyeven for longer missions.

Place, publisher, year, edition, pages
AAAI Press, 2016
Keywords
Aircraft, Cockpit, Pilot, Thermal Comfort, Modelling, Environmental Control System, ECS
National Category
Aerospace Engineering Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-126538 (URN)10.2514/6.2016-0172 (DOI)
Conference
SciTech 2016,AIAA Modeling and Simulation Technologies Conference San Diego, California, USA
Available from: 2016-03-30 Created: 2016-03-30 Last updated: 2018-07-18
Schminder, J., Nadali Najafabadi, H. & Gårdhagen, R. (2016). Learning by teaching: Student developed material for self-directed studies. In: The 12th International CDIO Conference: Proceedings - Full Papers. Paper presented at 12th International CDIO Conference, Turku, Finland, June 12-16, 2016 (pp. 750-759). Turku: Turku University of Applied Sciences
Open this publication in new window or tab >>Learning by teaching: Student developed material for self-directed studies
2016 (English)In: The 12th International CDIO Conference: Proceedings - Full Papers, Turku: Turku University of Applied Sciences , 2016, p. 750-759Conference paper, Published paper (Refereed)
Abstract [en]

The objective of the presented paper is to demonstrate how e-learning course material developed by the students can enhance active learning for self-directed studies outside the classroom in a flipped classroom concept. A method which merges different learning activities such as learning by teaching, video based teaching etc. was developed to improve the students’ personal and interpersonal engineering skills in relation to CDIO standards. In an effort to assess the students’ satisfaction and practical use of the students’ created material, a survey was conducted. Statistics, the students’ feedback, and observations show an increase in learning motivation, deepened understanding, and expanded communication skills.

Place, publisher, year, edition, pages
Turku: Turku University of Applied Sciences, 2016
Series
Research Reports from Turku University of Applied Sciences, ISSN 1796-9964 ; 45
Keywords
Learning by Teaching, Video, Multimedia, Lisam, Flipped Classroom, E-learning
National Category
Pedagogical Work
Identifiers
urn:nbn:se:liu:diva-129455 (URN)978-952-216-610-4 (ISBN)
Conference
12th International CDIO Conference, Turku, Finland, June 12-16, 2016
Available from: 2016-06-20 Created: 2016-06-20 Last updated: 2017-06-01Bibliographically approved
Gårdhagen, R., Carlsson, F. & Karlsson, M. (2015). Large Eddy Simulation of Pulsating Flow Before and After CoA Repair - CFD for Intervention Planning. Advances in Mechanical Engineering, 7(2)
Open this publication in new window or tab >>Large Eddy Simulation of Pulsating Flow Before and After CoA Repair - CFD for Intervention Planning
2015 (English)In: Advances in Mechanical Engineering, ISSN 1687-8132, E-ISSN 1687-8140, Vol. 7, no 2Article in journal (Refereed) Published
Abstract [en]

Large eddy simulation was applied to investigate hemodynamics in a model with coarctation of the aorta (CoA) and post-stenotic dilatation. Special focus was put on the role of hemodynamics for success of CoA repair. Several parameters previously identified as related to cardiovascular disease were studied. Known risk factors were observed both with CoA and after repair, and the restoration of the anatomy seems to be crucial for a successful result.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation / SAGE Publications, 2015
Keywords
Coarctation of the Aorta, CFD, Intervention Planning, Turbulence, Wall Shear Stress, Shear Rate
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-100917 (URN)10.1155/2014/971418 (DOI)000354083600087 ()
Available from: 2013-11-14 Created: 2013-11-14 Last updated: 2017-12-06Bibliographically approved
Gårdhagen, R. (2013). Turbulent Flow in Constricted Blood Vessels: Quantification of Wall Shear Stress Using Large Eddy Simulation. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Turbulent Flow in Constricted Blood Vessels: Quantification of Wall Shear Stress Using Large Eddy Simulation
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The genesis of atherosclerosis has previously been shown to be affected by the frictional load from the blood on the vessel wall, called the wall shear stress (WSS). Assessment of WSS can therefore provide important information for diagnoses, intervention planning, and follow‐up. Calculation of WSS requires high‐resolved velocity data from the vessel, which in turn can be obtained using computational fluid dynamics (CFD). In this work large eddy simulation LES was successfully used to simulate transitional flow in idealized as well as subject specific vessel models. It was shown that a scale resolving technique is to prefer for this application, since much valuable information otherwise is lost. Besides, Reynolds‐Averaged Navier‐Stokes (RANS) models have generally failed to predict this type of flow.

Non‐pulsating flows of Reynolds numbers up to 2 000 in a circular constricted pipe showed that turbulence is likely to occur in the post‐stenotic region, which resulted in a complex WSS pattern characterized by large spatial as well temporal fluctuations in all directions along the wall. Time averaged streamwise WSS was relatively high, while time averaged circumferential WSS was low, meaning that endothelial cells in that region would be exposed to oscillations in a stretched state in the streamwise direction and in a relaxed state in the circumferential direction.

Since every vessel is unique, so is also its WSS pattern. Hence the CFD simulations must be done in subject specific vessel models. Such can be created from anatomical information acquired with magnetic resonance imaging (MRI). MRI can also be used to obtain velocity boundary conditions for the simulation. This technique was used to investigate pulsating flow in a subject specific normal human aorta. It was shown that even the flow in healthy vessels can be very disturbed and turbulence like, and even for this case large WSS variations were seen. It was also shown that regions around branches from the aorta, known to be susceptible for atherosclerosis, were characterized by high time averaged WSS and high oscillatory shear index.

Finally, the predictive capability of CFD was investigated. An idealized model of a human aorta with a coarctation and post‐stenotic dilatation was studied before and after a possible repair of the constriction. The results suggested that small remaining abnormalities in the geometry may deteriorate the chances for a successful treatment. Also, high values of shear rate and Reynolds stresses were found in the dilatation after the constriction, which previous works have shown means increased risk for thrombus formation and hemolysis.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2013. p. 57
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1558
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-100918 (URN)10.3384/diss.diva-100918 (DOI)978-91-7519-473-8 (ISBN)
Public defence
2013-12-10, C3, hus C, Campus Valla, Linköpings universitet, Linköping, 10:15 (English)
Opponent
Supervisors
Available from: 2013-11-14 Created: 2013-11-14 Last updated: 2017-03-27Bibliographically approved
Bradley, A., Gårdhagen, R. & Karlsson, M. (2012). Bird-Like Wing Conguration for Pitch Control of a Tailless Aircraft. In: : . Paper presented at 50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition.
Open this publication in new window or tab >>Bird-Like Wing Conguration for Pitch Control of a Tailless Aircraft
2012 (English)Conference paper, Published paper (Other academic)
Abstract [en]

A numerical study of a small bird-like aircraft has been performed. The aim of the study was to investigate how a swing wing (actualized through a constant span morphing wing) can be used for pitch control of a tailless aircraft. The results show that a swing wing can be successfully used, and that the aircraft can be maintained in a trimmed state by only small adjustments of part of the wing. A comparison was also made with a Vortex lattice method, but these results significantly deviated from those obtained with CFD. Copyright © 2012 by the American Institute of Aeronautics and Astronautics, Inc.

Keywords
Aerodynamics, Conceptual design, CFD
National Category
Aerospace Engineering
Identifiers
urn:nbn:se:liu:diva-75568 (URN)10.2514/6.2012-248 (DOI)
Conference
50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition
Available from: 2012-03-08 Created: 2012-03-08 Last updated: 2016-03-14
Lantz, J., Gårdhagen, R. & Karlsson, M. (2012). Quantifying turbulent wall shear stress in a subject specific human aorta using large eddy simulation. Medical Engineering and Physics, 34(8), 1139-1148
Open this publication in new window or tab >>Quantifying turbulent wall shear stress in a subject specific human aorta using large eddy simulation
2012 (English)In: Medical Engineering and Physics, ISSN 1350-4533, E-ISSN 1873-4030, Vol. 34, no 8, p. 1139-1148Article in journal (Refereed) Published
Abstract [en]

In this study, large-eddy simulation (LES) is employed to calculate the disturbed flow field and the wall shear stress (WSS) in a subject specific human aorta. Velocity and geometry measurements using magnetic resonance imaging (MRI) are taken as input to the model to provide accurate boundary conditions and to assure the physiological relevance. In total, 50 consecutive cardiac cycles were simulated from which a phase average was computed to get a statistically reliable result. A decomposition similar to Reynolds decomposition is introduced, where the WSS signal is divided into a pulsating part (due to the mass flow rate) and a fluctuating part (originating from the disturbed flow). Oscillatory shear index (OSI) is plotted against time-averaged WSS in a novel way, and locations on the aortic wall where elevated values existed could easily be found. In general, high and oscillating WSS values were found in the vicinity of the branches in the aortic arch, while low and oscillating WSS were present in the inner curvature of the descending aorta. The decomposition of WSS into a pulsating and a fluctuating part increases the understanding of how WSS affects the aortic wall, which enables both qualitative and quantitative comparisons.

Place, publisher, year, edition, pages
Elsevier, 2012
Keywords
Human aorta, Atherosclerosis, Wall shear stress, Computational fluid dynamics, Scale resolving turbulence model, Reynolds decomposition
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-84887 (URN)10.1016/j.medengphy.2011.12.002 (DOI)000309028800016 ()
Note

Funding Agencies|Swedish research council|VR 2007-4085VR 2010-4282|National Supercomputer Centre (NSC)|SNIC022/09-11|

Available from: 2012-11-01 Created: 2012-10-26 Last updated: 2017-12-07
Karlsson, M., Lantz, J., Gårdhagen, R. & Renner, J. (2011). Biofluid Mechanics -LES and FSI. In: B. Skallerud and H.I. Andersson (Ed.), : . Paper presented at Sixth national conference on Computational Mechanics (MekIT'11), Trondheim, Norway, 23-24 May 2011 (pp. 23-28). tapir academic press
Open this publication in new window or tab >>Biofluid Mechanics -LES and FSI
2011 (English)In: / [ed] B. Skallerud and H.I. Andersson, tapir academic press , 2011, p. 23-28Conference paper, Published paper (Other academic)
Place, publisher, year, edition, pages
tapir academic press, 2011
Keywords
Biofluid, CFD, Human Aorta
National Category
Applied Mechanics
Identifiers
urn:nbn:se:liu:diva-104485 (URN)978-82-519-2798-7 (ISBN)
Conference
Sixth national conference on Computational Mechanics (MekIT'11), Trondheim, Norway, 23-24 May 2011
Available from: 2014-02-17 Created: 2014-02-17 Last updated: 2016-03-14
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-6634-797X

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