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Karlsson, Martin
Publications (10 of 19) Show all publications
Karlsson, M. (2010). Activity: Flow annual meeting 2010 (ed.). Paper presented at Flow Annual Meeting : 21/01/2010 - 21/01/2010. Paper presented at Flow Annual Meeting : 21/01/2010 - 21/01/2010.
Open this publication in new window or tab >>Activity: Flow annual meeting 2010
2010 (English)Conference paper, Published paper (Other (popular science, discussion, etc.))
Identifiers
urn:nbn:se:ltu:diva-41821 (URN)e5d14f90-07c0-11e0-b767-000ea68e967b (Local ID)e5d14f90-07c0-11e0-b767-000ea68e967b (Archive number)e5d14f90-07c0-11e0-b767-000ea68e967b (OAI)
Conference
Flow Annual Meeting : 21/01/2010 - 21/01/2010
Note
Startdatum: 21/01/2010; Slutdatum: 21/01/2010; Roll: Talare; Typ: Föreläsning / muntligt bidragAvailable from: 2016-10-03 Created: 2016-10-03 Last updated: 2017-11-24Bibliographically approved
Karlsson, M., Samuelsson, H. & Karlberg, M. (2010). Co-variance driven stochastic subspace identification approach for rotordynamics (ed.). In: (Ed.), (Ed.), 13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery 2010 (ISROMAC-13): . Paper presented at IFToMM International Conference on Rotordynamics : 12/09/2010 - 15/09/2010.
Open this publication in new window or tab >>Co-variance driven stochastic subspace identification approach for rotordynamics
2010 (English)In: 13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery 2010 (ISROMAC-13), 2010Conference paper, Published paper (Refereed)
National Category
Other Mechanical Engineering
Research subject
Computer Aided Design
Identifiers
urn:nbn:se:ltu:diva-30615 (URN)47a08e00-07be-11e0-b767-000ea68e967b (Local ID)47a08e00-07be-11e0-b767-000ea68e967b (Archive number)47a08e00-07be-11e0-b767-000ea68e967b (OAI)
Conference
IFToMM International Conference on Rotordynamics : 12/09/2010 - 15/09/2010
Projects
Fastelaboratoriet - VINNEXC
Note
Godkänd; 2010; 20130117 (ysko)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Karlberg, M., Karlsson, M., Karlsson, L. & Näsström, M. (2010). Dynamics of rotor systems with clearance and weak pedestals in full contact (ed.). In: (Ed.), (Ed.), 13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery 2010 (ISROMAC-13): Honolulu, Hawaii, USA, 4 - 7 April 2010. Paper presented at International Symposium on Transport Phenomena and Dynamics of Rotating Machinery : 03/04/2010 - 07/04/2010 (pp. 531-536). Red Hook, NY: Curran Associates, Inc.
Open this publication in new window or tab >>Dynamics of rotor systems with clearance and weak pedestals in full contact
2010 (English)In: 13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery 2010 (ISROMAC-13): Honolulu, Hawaii, USA, 4 - 7 April 2010, Red Hook, NY: Curran Associates, Inc., 2010, p. 531-536Conference paper, Published paper (Refereed)
Abstract [en]

Many rotating machineries are supported by bearings with clearance, which are further clamped in, compared to the bearing stiffness, weak pedestals. As have been reported in several studies, it is essential to choose a proper clearance in order to avoid unwanted vibrations. When rotating machineries supported by bearings with clearance are subjected to stationary loads (gravity, magnetic pull etc.), it may not loose contact between the shaft and the bearing (i.e. full contact). However, even in full contact unwanted dynamics can occur which is of interest in this paper. It is found that the clearance give raise to anisotropic pedestal stiffness. It is further shown that some of the resonance frequencies decrease with the clearance.

Place, publisher, year, edition, pages
Red Hook, NY: Curran Associates, Inc., 2010
Keywords
Engineering mechanics - Other engineering mechanics, Fasteass, Teknisk mekanik - Övrig teknisk mekanik
National Category
Other Mechanical Engineering
Research subject
Computer Aided Design
Identifiers
urn:nbn:se:ltu:diva-34051 (URN)826f17b0-3a44-11df-a0f4-000ea68e967b (Local ID)9781617388484 (ISBN)826f17b0-3a44-11df-a0f4-000ea68e967b (Archive number)826f17b0-3a44-11df-a0f4-000ea68e967b (OAI)
Conference
International Symposium on Transport Phenomena and Dynamics of Rotating Machinery : 03/04/2010 - 07/04/2010
Projects
Fastelaboratoriet - VINNEXC
Note
Godkänd; 2010; 20100328 (magkar)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-05-09Bibliographically approved
Karlsson, M. (2010). Electromechanical interactions in hydropower rotor systmes (ed.). Paper presented at Hydro 2009 : 26/09/2009 - 28/09/2009. Paper presented at Hydro 2009 : 26/09/2009 - 28/09/2009.
Open this publication in new window or tab >>Electromechanical interactions in hydropower rotor systmes
2010 (English)Conference paper, Oral presentation only (Refereed)
National Category
Other Mechanical Engineering
Research subject
Computer Aided Design
Identifiers
urn:nbn:se:ltu:diva-40133 (URN)f2131640-07bf-11e0-b767-000ea68e967b (Local ID)f2131640-07bf-11e0-b767-000ea68e967b (Archive number)f2131640-07bf-11e0-b767-000ea68e967b (OAI)
Conference
Hydro 2009 : 26/09/2009 - 28/09/2009
Note
Godkänd; 2010; 20101214 (karmar)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2017-11-25Bibliographically approved
Karlsson, M., Myllerup, C. & Chan, D. (2010). Electromechanical interactions of a variable speed drive driven compressor train (ed.). Paper presented at IFToMM International Conference on Rotordynamics : 12/09/2010 - 15/09/2010. Paper presented at IFToMM International Conference on Rotordynamics : 12/09/2010 - 15/09/2010.
Open this publication in new window or tab >>Electromechanical interactions of a variable speed drive driven compressor train
2010 (English)Conference paper, Oral presentation only (Refereed)
National Category
Other Mechanical Engineering
Research subject
Computer Aided Design
Identifiers
urn:nbn:se:ltu:diva-39254 (URN)deb32d20-07be-11e0-b767-000ea68e967b (Local ID)deb32d20-07be-11e0-b767-000ea68e967b (Archive number)deb32d20-07be-11e0-b767-000ea68e967b (OAI)
Conference
IFToMM International Conference on Rotordynamics : 12/09/2010 - 15/09/2010
Note
Godkänd; 2010; 20101214 (karmar)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2017-11-25Bibliographically approved
Karlsson, M., Lundin, U. & Aidanpää, J.-O. (2010). Rotordynamical analysis of a fourteen pole synchronous generator due to whirling dependent electromagnetical forces (ed.). Paper presented at IFToMM International Conference on Rotordynamics : 12/09/2010 - 15/09/2010. Paper presented at IFToMM International Conference on Rotordynamics : 12/09/2010 - 15/09/2010.
Open this publication in new window or tab >>Rotordynamical analysis of a fourteen pole synchronous generator due to whirling dependent electromagnetical forces
2010 (English)Conference paper, Oral presentation only (Refereed)
National Category
Other Mechanical Engineering Applied Mechanics
Research subject
Computer Aided Design; Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-32500 (URN)7043bbb0-07bf-11e0-b767-000ea68e967b (Local ID)7043bbb0-07bf-11e0-b767-000ea68e967b (Archive number)7043bbb0-07bf-11e0-b767-000ea68e967b (OAI)
Conference
IFToMM International Conference on Rotordynamics : 12/09/2010 - 15/09/2010
Note
Godkänd; 2010; 20101214 (karmar)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Karlsson, M., Samuelsson, H. & Karlberg, M. (2010). Using operational modal analysis to determine rotordynamic modes (ed.). In: (Ed.), (Ed.), 13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery 2010 (ISROMAC-13): Honolulu, Hawaii, USA, 4 - 7 April 2010. Paper presented at International Symposium on Transport Phenomena and Dynamics of Rotating Machinery : 03/04/2010 - 07/04/2010 (pp. 527-530). Red Hook, NY: Curran Associates, Inc.
Open this publication in new window or tab >>Using operational modal analysis to determine rotordynamic modes
2010 (English)In: 13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery 2010 (ISROMAC-13): Honolulu, Hawaii, USA, 4 - 7 April 2010, Red Hook, NY: Curran Associates, Inc., 2010, p. 527-530Conference paper, Published paper (Refereed)
Abstract [en]

Operational Modal Analysis (OMA) has lately been a more and more common tool in structural dynamics. The benefits compared to Experimental Modal Analysis (EMA) are that one does not need any artificial excitation and that the structure does not have to be at rest, which is a requirement of EMA. So far, OMA has won terrain for modal analysis of large structures such as buildings and bridges, and for vehicles such as helicopters and ships. For rotating equipment, OMA has not yet been widely used or evaluated. Rotordynamic modes depend on the operating condition of the rotating equipment (e.g. speed). Hence the fundamental requirement of EMA that the testing object should be at rest is not fulfilled. Mapping of critical speeds during start-up and coursing down gives some important operating information, but it will not give all modal information needed to validate a theoretical model or to verify the requirements of damping. The aim of this paper is to evaluate OMA for rotordynamical modal analysis. A numerical model of rotor is used as test object. The response is analyzed with various SSI methods. The results are presented in a Campbell diagram, showing the frequency dependent rotor modes as well as the structural modes. Values for the damping are presented in a root locus plot. These results agree well when comparing the results with a direct naturalvalue solver for the numerical model. It is concluded that OMA can be applied to rotordynamical applications. However, identifying corresponding modes at different speeds can be difficult at field measurements; hence the authors suggest further research and development of Operational Modal Analysis in this specific area.

Place, publisher, year, edition, pages
Red Hook, NY: Curran Associates, Inc., 2010
National Category
Other Mechanical Engineering
Research subject
Computer Aided Design
Identifiers
urn:nbn:se:ltu:diva-40005 (URN)ef827240-3998-11df-a0f4-000ea68e967b (Local ID)9781617388484 (ISBN)ef827240-3998-11df-a0f4-000ea68e967b (Archive number)ef827240-3998-11df-a0f4-000ea68e967b (OAI)
Conference
International Symposium on Transport Phenomena and Dynamics of Rotating Machinery : 03/04/2010 - 07/04/2010
Projects
Fastelaboratoriet - VINNEXC
Note
Godkänd; 2010; 20100327 (magkar)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2017-11-25Bibliographically approved
Aidanpää, J.-O., Gustavsson, R. K., Lundström, N. L. P., Karlsson, M., Calleecharan, Y., Nässelqvist, M., . . . Lundin, U. (2009). Developments in rotor dynamical modeling of hydropower units (ed.). In: (Ed.), Kshitij Gupta (Ed.), Proceedings of the IUTAM Symposium on Emerging Trends in Rotor Dynamics: held in New Delhi, India, March 23 - March 26, 2009. Paper presented at IUTAM Symposium on Emerging Trends in Rotor Dynamics : 23/03/2009 - 26/03/2009. Dordrecht: Encyclopedia of Global Archaeology/Springer Verlag
Open this publication in new window or tab >>Developments in rotor dynamical modeling of hydropower units
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2009 (English)In: Proceedings of the IUTAM Symposium on Emerging Trends in Rotor Dynamics: held in New Delhi, India, March 23 - March 26, 2009 / [ed] Kshitij Gupta, Dordrecht: Encyclopedia of Global Archaeology/Springer Verlag, 2009Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Dordrecht: Encyclopedia of Global Archaeology/Springer Verlag, 2009
Series
IUTAM bookseries ; 25
National Category
Applied Mechanics Other Mechanical Engineering
Research subject
Solid Mechanics; Computer Aided Design
Identifiers
urn:nbn:se:ltu:diva-38598 (URN)d0b85530-df2c-11de-bae5-000ea68e967b (Local ID)9789400700192 (ISBN)d0b85530-df2c-11de-bae5-000ea68e967b (Archive number)d0b85530-df2c-11de-bae5-000ea68e967b (OAI)
Conference
IUTAM Symposium on Emerging Trends in Rotor Dynamics : 23/03/2009 - 26/03/2009
Note
Godkänd; 2009; 20091202 (joa)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2017-11-25Bibliographically approved
Karlsson, M., Nilsson, H. & Aidanpää, J.-O. (2009). Numerical estimation of torsional dynamic coefficients of a hydraulic turbine (ed.). Paper presented at . International Journal of Rotating Machinery
Open this publication in new window or tab >>Numerical estimation of torsional dynamic coefficients of a hydraulic turbine
2009 (English)In: International Journal of Rotating Machinery, ISSN 1023-621X, E-ISSN 1542-3034Article in journal (Refereed) Published
Abstract [en]

The rotordynamic behavior of a hydraulic turbine is influenced by fluid-rotor interactions at the turbine runner. In this paper computational fluid dynamics (CFDs) are used to numerically predict the torsional dynamic coefficients due to added polar inertia, damping, and stiffness of a Kaplan turbine runner. The simulations are carried out for three operating conditions, one at about 35% load, one at about 60% load (near best efficiency), and one at about 70% load. The runner rotational speed is perturbed with a sinusoidal function with different frequencies in order to estimate the coefficients of added polar inertia and damping. It is shown that the added coefficients are dependent of the load and the oscillation frequency of the runner. This affect the system's eigenfrequencies and damping. The eigenfrequency is reduced with up to 65% compared to the eigenfrequency of the mechanical system without the fluid interaction. The contribution to the damping ratio varies between 30-80% depending on the load. Hence, it is important to consider these added coefficients while carrying out dynamic analysis of the mechanical system.

National Category
Other Mechanical Engineering Applied Mechanics
Research subject
Computer Aided Design; Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-15133 (URN)10.1155/2009/349397 (DOI)2-s2.0-68249143374 (Scopus ID)e9c5bc70-8d6f-11de-8da0-000ea68e967b (Local ID)e9c5bc70-8d6f-11de-8da0-000ea68e967b (Archive number)e9c5bc70-8d6f-11de-8da0-000ea68e967b (OAI)
Note
Validerad; 2009; Bibliografisk uppgift: Paper id:: Article ID 349397; 20090820 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Karlsson, M., Nilsson, H. & Aidanpää, J.-O. (2008). Influence of inlet boundary conditions in the prediction of rotor dynamic forces and moments for a hydraulic turbine using CFD (ed.). In: (Ed.), (Ed.), ISROMAC-12: the Twelfth International Symposium on Transport Phenomena and Dynamics of Rotating Machinery ; Honolulu, Hawaii, February 17 - 22, 2008, Pacific Center of Thermal-Fluids Engineering. Paper presented at International Symposium on Transport Phenomena and Dynamics of Rotating Machinery : 17/02/2008 - 22/02/2008. Honolulu
Open this publication in new window or tab >>Influence of inlet boundary conditions in the prediction of rotor dynamic forces and moments for a hydraulic turbine using CFD
2008 (English)In: ISROMAC-12: the Twelfth International Symposium on Transport Phenomena and Dynamics of Rotating Machinery ; Honolulu, Hawaii, February 17 - 22, 2008, Pacific Center of Thermal-Fluids Engineering, Honolulu, 2008Conference paper, Published paper (Refereed)
Abstract [en]

The rotordynamic behavior of a hydraulic turbine is influenced by fluid-rotor interactions at the turbine runner. In this paper computational fluid dynamics (CFD) is used to numerically predict the rotordynamical excitation forces due to the flow through a hydraulic turbine runner. The simulations are carried out for three different boundary conditions. One axi-symmetric inlet boundary condition, and two axi-periodic boundary conditions. The two latter are obtained from separate simulations of wicket gate and spiral casing flow. It is found that the inlet boundary condition significantly affects the rotordynamical forces and moments.

Place, publisher, year, edition, pages
Honolulu: , 2008
National Category
Other Mechanical Engineering
Research subject
Computer Aided Design
Identifiers
urn:nbn:se:ltu:diva-32142 (URN)68760610-a29e-11dc-ac39-000ea68e967b (Local ID)68760610-a29e-11dc-ac39-000ea68e967b (Archive number)68760610-a29e-11dc-ac39-000ea68e967b (OAI)
Conference
International Symposium on Transport Phenomena and Dynamics of Rotating Machinery : 17/02/2008 - 22/02/2008
Note
Godkänd; 2008; Bibliografisk uppgift: 1 CD-ROM; 20071204 (karmar)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
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