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Lycksam, Henrik
Publications (10 of 16) Show all publications
Larsson, S., Lundström, S. & Lycksam, H. (2018). Tomographic PIV of flow through ordered thin porous media. Experiments in Fluids, 59(6), Article ID 96.
Open this publication in new window or tab >>Tomographic PIV of flow through ordered thin porous media
2018 (English)In: Experiments in Fluids, ISSN 0723-4864, E-ISSN 1432-1114, Vol. 59, no 6, article id 96Article in journal (Refereed) Published
Abstract [en]

Pressure-driven flow in a model of a thin porous medium is investigated using tomographic particle image velocimetry. The solid parts of the porous medium have the shape of vertical cylinders placed on equal interspatial distance from each other. The array of cylinders is confined between two parallel plates, meaning that the permeability is a function of the diameter and height of the cylinders, as well as their interspatial distance. Refractive index matching is applied to enable measurements without optical distortion and a dummy cell is used for the calibration of the measurements. The results reveal that the averaged flow field changes substantially as Reynolds number increases, and that the wakes formed downstream the cylinders contain complex, three-dimensional vortex structures hard to visualize with only planar measurements. An interesting observation is that the time-averaged velocity maximum changes position as Reynolds number increases. For low Reynolds number flow, the maximum is in the middle of the channel, while, for the higher Reynolds numbers investigated, two maxima appear closer to each bounding lower and upper wall.

Place, publisher, year, edition, pages
Springer, 2018
National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-68773 (URN)10.1007/s00348-018-2548-6 (DOI)000459501500001 ()2-s2.0-85047216388 (Scopus ID)
Note

Validerad;2018;Nivå 1;20180525 (marisr)

Available from: 2018-05-17 Created: 2018-05-17 Last updated: 2019-03-14Bibliographically approved
Khayamyan, S., Lundström, S., Hellström, G., Gren, P. & Lycksam, H. (2017). Measurements of Transitional and Turbulent Flow in a Randomly Packed Bed of Spheres with Particle Image Velocimetry. Transport in Porous Media, 116(1), 413-431
Open this publication in new window or tab >>Measurements of Transitional and Turbulent Flow in a Randomly Packed Bed of Spheres with Particle Image Velocimetry
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2017 (English)In: Transport in Porous Media, ISSN 0169-3913, E-ISSN 1573-1634, Vol. 116, no 1, p. 413-431Article in journal (Refereed) Published
Abstract [en]

Particle image velocimetry (PIV) has been used to investigate transitional and turbulent flow in a randomly packed bed of mono-sized transparent spheres at particle Reynolds number, (Formula presented.). The refractive index of the liquid is matched with the spheres to provide optical access to the flow within the bed without distortions. Integrated pressure drop data yield that Darcy law is valid at (Formula presented.). The PIV measurements show that the velocity fluctuations increase and that the time-averaged velocity distribution start to change at lower (Formula presented.). The probability for relatively low and high velocities decreases with (Formula presented.) and recirculation zones that appear in inertia dominated flows are suppressed by the turbulent flow at higher (Formula presented.). Hence there is a maximum of recirculation at about (Formula presented.). Finally, statistical analysis of the spatial distribution of time-averaged velocities shows that the velocity distribution is clearly and weakly self-similar with respect to (Formula presented.) for turbulent and laminar flow, respectively

Place, publisher, year, edition, pages
Springer, 2017
National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-60561 (URN)10.1007/s11242-016-0781-0 (DOI)000394167300019 ()2-s2.0-84994430906 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-02-01 (andbra)

 

Available from: 2016-11-20 Created: 2016-11-20 Last updated: 2018-09-27Bibliographically approved
Neikter, M., Forsberg, F., Lycksam, H., Pederson, R. & Antti, M.-L. (2017). Microstructure and Defects in Additive Manufactured Titanium: a Comparison Between Microtomography and Optical Microscopy. In: : . Paper presented at 3rd International Conference on Tomography of Materials and Structures, Lund, Sweden, 26-30 June 2017.
Open this publication in new window or tab >>Microstructure and Defects in Additive Manufactured Titanium: a Comparison Between Microtomography and Optical Microscopy
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2017 (English)Conference paper, Oral presentation with published abstract (Other academic)
Abstract [en]

The aim of this work has been to compare two different analysing methods;x-ray microtomography and light optical microscopy, when it comes to defects and microstructure of additively manufactured Ti-6Al-4V. The results showthat both techniqueshave theirpros and cons:microtomography is the preferred choicefor defect detectionby analysing the full 3D sample volume, while light optical microscopy is better for analysing finer details in 2D.

National Category
Metallurgy and Metallic Materials Other Materials Engineering Fluid Mechanics and Acoustics
Research subject
Engineering Materials; Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-65063 (URN)
Conference
3rd International Conference on Tomography of Materials and Structures, Lund, Sweden, 26-30 June 2017
Available from: 2017-08-14 Created: 2017-08-14 Last updated: 2018-04-25Bibliographically approved
Khayamyan, S., Lundström, S., Gren, P., Lycksam, H. & Hellström, G. (2017). Transitional and Turbulent Flow in a Bed of Spheres as Measured with Stereoscopic Particle Image Velocimetry. Transport in Porous Media, 117(1), 45-67
Open this publication in new window or tab >>Transitional and Turbulent Flow in a Bed of Spheres as Measured with Stereoscopic Particle Image Velocimetry
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2017 (English)In: Transport in Porous Media, ISSN 0169-3913, E-ISSN 1573-1634, Vol. 117, no 1, p. 45-67Article in journal (Refereed) Published
Abstract [en]

Stereoscopic particle image velocimetry has been used to investigate inertia dominated, transitional and turbulent flow in a randomly packed bed of monosized PMMA spheres. By using an index-matched fluid, the bed is optically transparent and measurements can be performed in an arbitrary position within the porous bed. The velocity field observations are carried out for particle Reynolds numbers, (Formula presented.), between 20 and 3220, and the sampling is done at a frequency of 75 Hz. Results show that, in porous media, the dynamics of the flow can vary significantly from pore to pore. At (Formula presented.) around 400 the spatially averaged time fluctuations of total velocity reach a maximum and the spatial variation of the time-averaged total velocity, (Formula presented.) increases up to about the same (Formula presented.) and then it decreases. Also in the studied planes, a considerable amount of the fluid moves in the perpendicular directions to the main flow direction and the time-averaged magnitude of the velocity in the main direction, (Formula presented.), has an averaged minimum of 40% of the magnitude of (Formula presented.) at (Formula presented.) about 400. For (Formula presented.), this ratio is nearly constant and (Formula presented.) is on average a little bit less than 50% of (Formula presented.). The importance of the results for longitudinal and transverse dispersion is discussed.

Place, publisher, year, edition, pages
Springer, 2017
National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-61843 (URN)10.1007/s11242-017-0819-y (DOI)000395621700003 ()2-s2.0-85009872759 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-03-06 (andbra)

Available from: 2017-02-07 Created: 2017-02-07 Last updated: 2018-10-04Bibliographically approved
Khayamyan, S., Lundström, S., Lycksam, H., Gren, P. & Hellström, G. (2016). PIV measurements within a randomly packed bed of spheres (ed.). Paper presented at Interpore 2016 : 8th International Conference on Porous Media & Annual Meeting 09/05/2016 - 12/05/2016. Paper presented at Interpore 2016 : 8th International Conference on Porous Media & Annual Meeting 09/05/2016 - 12/05/2016.
Open this publication in new window or tab >>PIV measurements within a randomly packed bed of spheres
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2016 (English)Conference paper, Oral presentation only (Refereed)
National Category
Fluid Mechanics and Acoustics Applied Mechanics
Research subject
Fluid Mechanics; Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-27624 (URN)11f2898d-c1e8-4ad1-9fb2-2c2b0a30f10d (Local ID)11f2898d-c1e8-4ad1-9fb2-2c2b0a30f10d (Archive number)11f2898d-c1e8-4ad1-9fb2-2c2b0a30f10d (OAI)
Conference
Interpore 2016 : 8th International Conference on Porous Media & Annual Meeting 09/05/2016 - 12/05/2016
Note
Godkänd; 2016; 20160511 (stlu)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-25Bibliographically approved
Hellström, G., Andersson, A., Leonardsson, K., Lycksam, H., Lundström, S. & Lundqvist, H. (2016). Simulation and experiments of entrance flow conditions to a fishway (ed.). Paper presented at International Symposium on Ecohydraulics : 07/02/2016 - 12/02/2016. Paper presented at International Symposium on Ecohydraulics : 07/02/2016 - 12/02/2016.
Open this publication in new window or tab >>Simulation and experiments of entrance flow conditions to a fishway
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2016 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

When migrating fish tries to pass around man made obstacles such as hydropower dams with the aid of fish passages it is important that the migrating path is constructed in an efficient manner. By designing the entrance of the fishway in a manner that gives attractive flow conditions for migrating fish, the overall passage efficiency can be increased. In this study two alternative design solutions have been studied with numerical simulations, lab-scale experiments and in-field testing to achieve such attractive flow. Designs studied are constructions yielding a submerged jet, in order to increase the velocity of the flow at the entrance, and a half-cylinder, in order to create vortices that the fishes can utilize when continuing their journey towards their spawning grounds. A combination of the previous mentioned setups was also investigated. A first result shows that the increase in velocity decreases the residence time downstream the fishway and increases the total passage efficiency while the result from the vorticity generation is inconclusive at this point. The combination of the two designs shows similar passage efficiency as with only velocity increase although it does not show the same decrease in residence time. Improvements on the design of the vorticity generator and shape optimization of the construction generating the jet could further improve the efficiency of the fishway

National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-34803 (URN)918b2e61-b0d6-438b-b058-5daf59069ae7 (Local ID)918b2e61-b0d6-438b-b058-5daf59069ae7 (Archive number)918b2e61-b0d6-438b-b058-5daf59069ae7 (OAI)
Conference
International Symposium on Ecohydraulics : 07/02/2016 - 12/02/2016
Note
Godkänd; 2016; 20160418 (gunhel)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2017-11-29Bibliographically approved
Carlsson, P., Lycksam, H., Gren, P., Gebart, R., Wiinikka, H. & Iisa, K. (2013). High-speed imaging of biomass particles heated with a laser (ed.). Paper presented at International Symposium on Analytical and Applied Pyrolysis : 21/05/2012 - 25/05/2012. Journal of Analytical and Applied Pyrolysis, 103, 278-286
Open this publication in new window or tab >>High-speed imaging of biomass particles heated with a laser
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2013 (English)In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 103, p. 278-286Article in journal (Refereed) Published
Abstract [en]

In this work two types of lignocellulosic biomass particles, European spruce and American hardwood (particle sizes from 100 μm to 500 μm) were pyrolysed with a continuous wave 2 W Nd:YAG laser. Simultaneously a high-speed camera was used to capture the behavior of the biomass particle as it was heated for about 0.1 s. Cover glasses were used as a sample holder which allowed for light microscope studies after the heating. Since the cover glasses are not initially heated by the laser, vapors from the biomass particle are quenched on the glass within about 1 particle diameter from the initial particle. Image processing was used to track the contour of the biomass particle and the enclosed area of the contour was calculated for each frame.The main observations are: There is a significant difference between how much surface energy is needed to pyrolyses the spruce (about 75% more) compared to the hardwood. The oil-like substance which appeared on the glass during the experiment is solid at room temperature and shows different levels of transparency. A fraction of this substance is water soluble. A brownish coat is seen on the unreacted biomass. The biomass showed insignificant swelling as it was heated. The biomass particle appears to melt and boil at the front that is formed between the laser beam and the biomass particle. The part of the particle that is not subjected to the laser beam seems to be unaffected.

National Category
Fluid Mechanics and Acoustics Applied Mechanics Energy Engineering
Research subject
Fluid Mechanics; Experimental Mechanics; Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-32454 (URN)10.1016/j.jaap.2012.11.020 (DOI)000323852400038 ()2-s2.0-84881251454 (Scopus ID)6f4cd8b9-c6c3-4058-8ecc-0cce7767c23b (Local ID)6f4cd8b9-c6c3-4058-8ecc-0cce7767c23b (Archive number)6f4cd8b9-c6c3-4058-8ecc-0cce7767c23b (OAI)
Conference
International Symposium on Analytical and Applied Pyrolysis : 21/05/2012 - 25/05/2012
Note
Validerad; 2013; 20130102 (ysko); Konferensartikel i tidskriftAvailable from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-07-10Bibliographically approved
Lycksam, H., Sjödahl, M., Gren, P., Öhman, M. & Gebart, R. (2012). High-speed interferometric measurement and visualization of the conversion of a black liquor droplet during laser heating (ed.). Paper presented at . Optics and lasers in engineering, 50(11), 1654-1661
Open this publication in new window or tab >>High-speed interferometric measurement and visualization of the conversion of a black liquor droplet during laser heating
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2012 (English)In: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 50, no 11, p. 1654-1661Article in journal (Refereed) Published
Abstract [en]

Black liquor is a mix of organic and inorganic materials that is left after the kraft pulping process. In a modern pulp mill the pulping chemicals and the energy in the black liquor is recovered and used in the pulping cycle by burning the black liquor in a recovery burner. An alternative to the recovery boiler is to gasify the black liquor to produce an energy rich synthesis gas that can be upgraded into synthetic fuels or chemicals. Characterization of black liquor has mostly been done under conditions that are relevant for recovery boilers but the conditions in a gasifier differ significantly from this. In particular the droplets are much smaller and the heating rates are much higher. This paper presents an optical interferometric technique that has the potential to produce data under relevant conditions for gasification. In the paper, results are measured at atmospheric conditions and with relatively low heating rate. However, the method can be applied also for pressurized conditions and at heating rates that are only limited by the frame rate of the digital camera that is used to capture the transient event when the droplets are heated. In the paper the dynamic properties of the gas ejected from and the swelling during conversion of a single droplet are measured

National Category
Fluid Mechanics and Acoustics Applied Mechanics Energy Engineering
Research subject
Fluid Mechanics; Experimental Mechanics; Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-10207 (URN)10.1016/j.optlaseng.2012.05.001 (DOI)000307620900021 ()2-s2.0-84864287158 (Scopus ID)8f8423fe-791c-4f6d-a520-149558104cfb (Local ID)8f8423fe-791c-4f6d-a520-149558104cfb (Archive number)8f8423fe-791c-4f6d-a520-149558104cfb (OAI)
Note
Validerad; 2012; 20120806 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Lycksam, H. (2011). Time resolved digital holographic interferometry through disturbed phase objects (ed.). (Doctoral dissertation). Paper presented at . Luleå: Luleå tekniska universitet
Open this publication in new window or tab >>Time resolved digital holographic interferometry through disturbed phase objects
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
Tidsupplöst digital holografisk interferometri genom störda fasobjekt
Abstract [en]

Digital holographic interferometry is an optical measurement technique based on the work by Powell and Stetson in 1965. The basic principle of the method is that the whole light wave (both amplitude and phase) from an opaque surface or transparent object can be captured and stored using a single camera. By comparing the phase of the light waves captured at different times it is possible to detect very small surface deformations (for opaque objects) or refractive index changes (for transparent objects). The fact that the method is sensitive also for transparent object is a problem when measuring surface deformations that occur on the same timescale as the random fluctuations in the surrounding medium (most often air) since these effects will be added together in the measurement. In a controlled laboratory environment the levels of air disturbances can often be kept at reasonably low levels, but an interesting new application of the technique would be for process supervision in the manufacturing and process industry where the levels of disturbances are much higher. The purpose of this research has been to develop methods for separating the effects of object deformations and air disturbances from each other by digital processing of the measured data. A large part of the work has consisted of constructing experimental setups, developing algorithms and performing numerical simulations. Air disturbances tend to have fluctuations on a very wide range of time scales. To capture the fast fluctuations a high-speed holographic imaging system has been used throughout this work. The slow fluctuations are captured using long time sequences. This creates an enormous amount of data and handling and pre-processing this data has been one of the initial challenges.Air disturbances are very different depending upon how they are generated. Much of the work has therefore been to gain some understanding of different types of air disturbances such as convection flows surrounding hot objects, gas ejection from heated material (black liquor) and more controlled channel flows with fully developed turbulence. The type of imaging system used will also influence how a certain air disturbance will affect a measurement. The difference between telecentric and conventional imaging systems has been discussed and in connection with that a method of depth-resolved velocity measurements in channel flows has been devised.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2011
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-17906 (URN)5cc53c78-c8f7-4ba4-b10f-42b7c9f7117b (Local ID)978-91-7439-319-4 (ISBN)5cc53c78-c8f7-4ba4-b10f-42b7c9f7117b (Archive number)5cc53c78-c8f7-4ba4-b10f-42b7c9f7117b (OAI)
Note
Godkänd; 2011; 20110906 (henlyc); DISPUTATION Ämnesområde: Experimentell mekanik/Experimental Mechanics Opponent: Associate Professor Pierre Slangen, Ecole des Mines D’Alès, AlèsCedex, France Ordförande: Professor Mikael Sjödahl, Institutionen för teknikvetenskap och matematik, Luleå tekniska universitet, Luleå Tid: Torsdag den 27 oktober 2011, kl 10.00 Plats: E231, Luleå tekniska universitetAvailable from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved
Lycksam, H., Sjödahl, M. & Gren, P. (2010). Measurement of spatiotemporal phase statistics in turbulent air flow using high-speed digital holographic interferometry (ed.). Paper presented at . Applied Optics, 49(8), 1314-1322
Open this publication in new window or tab >>Measurement of spatiotemporal phase statistics in turbulent air flow using high-speed digital holographic interferometry
2010 (English)In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 49, no 8, p. 1314-1322Article in journal (Refereed) Published
Abstract [en]

We describe a method of measuring spatiotemporal (ST) structure and covariance functions of the phase fluctuations in a collimated light beam propagated through a region of refractive index turbulence. The measurements are performed in a small wind tunnel, in which a turbulent temperature field is created using heated wires at the inlet of the test section. A collimated sheet of light is sent through the channel, and the phase fluctuations across the sheet are measured. The spatial phase structure function can be estimated from a series of images captured at an arbitrary frame rate by spatial phase unwrapping, whereas the ST structure function requires a time resolved measurement and a full three-dimensional unwrapping. The measured spatial phase structure function shows agreement with the Kolmogorov theory with a pronounced inertial subrange, which is taken as a validation of the method. Because of turbulent mixing in the boundary layers close to the walls of the channel, the flow will not obey the Taylor hypothesis of frozen turbulence. This can be clearly seen in the ST structure function calculated in a coordinate system that moves along with the bulk flow. At zero spatial separation, this function should always be zero according to the Taylor hypothesis, but due to the mixing effect there will be a growth in the structure function with increasing time difference depending on the rate of mixing.

National Category
Applied Mechanics
Research subject
Experimental Mechanics
Identifiers
urn:nbn:se:ltu:diva-6735 (URN)10.1364/AO.49.001314 (DOI)000275390200015 ()20220886 (PubMedID)2-s2.0-77949793593 (Scopus ID)504eecf0-38b5-11df-a0f4-000ea68e967b (Local ID)504eecf0-38b5-11df-a0f4-000ea68e967b (Archive number)504eecf0-38b5-11df-a0f4-000ea68e967b (OAI)
Note
Validerad; 2010; 20100326 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
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