Change search
Link to record
Permanent link

Direct link
BETA
Publications (6 of 6) Show all publications
Pantea, H. J., Misiulia, D., Hellström, J. G. & Gebart, R. (2018). Modeling of Particle-Laden Cold Flow in a Cyclone Gasifier. Journal of Fluids Engineering - Trancactions of The ASME, 141(2), Article ID 021302.
Open this publication in new window or tab >>Modeling of Particle-Laden Cold Flow in a Cyclone Gasifier
2018 (English)In: Journal of Fluids Engineering - Trancactions of The ASME, ISSN 0098-2202, E-ISSN 1528-901X, Vol. 141, no 2, article id 021302Article in journal (Refereed) Published
Abstract [en]

Isothermal transient Eulerian–Lagrangian simulation of the turbulent gas–solid flow in a cyclone gasifier with two inlet tubes at 890 °C has been performed. The single-phase gas flow is modeled using SSG Reynolds stress turbulence model. Ten thousand representative solid particles of different sizes are injected from each inlet continuously at every second of simulation time. Particles are finally stopped as soon as they arrive at the outlet or reach the bottom plate of the gasifier. The effect of particle-to-gas coupling on the pressure and velocity of the flow and particles motion inside the gasifier is studied. The numerical approach can reasonably predict the impact of particle load on the gas flow as presented in the experimental results. Single particles are traveled throughout the transient gas flow field by using Lagrangian approach. High temperature of the gas flow inside the gasifier has significant effects on the swirl intensity reduction, damping the turbulence in the core region, pressure, and particle behaviors. However, the presence of solid particles does not have a notable influence on the swirl intensity and turbulence.

Place, publisher, year, edition, pages
The American Society of Mechanical Engineers (ASME), 2018
National Category
Engineering and Technology Energy Engineering Fluid Mechanics and Acoustics
Research subject
Energy Engineering; Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-70480 (URN)10.1115/1.4040929 (DOI)000452773200012 ()2-s2.0-85052003087 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-08-31 (svasva)

Available from: 2018-08-17 Created: 2018-08-17 Last updated: 2019-01-30Bibliographically approved
Misiulia, D., Andersson, A. G. & Lundström, S. (2017). Effects of the inlet angle on the collection efficiency of a cyclone with helical-roof inlet. Powder Technology, 305, 48-55
Open this publication in new window or tab >>Effects of the inlet angle on the collection efficiency of a cyclone with helical-roof inlet
2017 (English)In: Powder Technology, ISSN 0032-5910, E-ISSN 1873-328X, Vol. 305, p. 48-55Article in journal (Refereed) Published
Abstract [en]

The effects of inlet angle on the collection efficiency of a cyclone with helical-roof inlet have been computationally investigated using Large Eddy Simulations with the dynamic Smagorinsky-Lilly subgrid-scale model for five different inlet angles (7°, 11°, 15°, 20° and 25°). Forty thousand individual particles were tracked through the unsteady flow field using the Lagrangian approach. In order to reveal the collection efficiency of a cyclone with helical-roof inlet properly, simulation time should not be < 3.5 times the average flow residence time. Particles which diameter is close to the cyclone cut size have the longest residence times while particles of 10–25 μm in diameter have the shortest. Based on the simulations, expressions for the cut size and Euler number normalized with the mean axial velocity in a cyclone with helical-roof inlet of different inlet angles are derived. The results show that, increasing the inlet angle increases the cyclone cut size and as a result reduces cyclone collection efficiency. At the same time, it decreases the cyclone pressure drop coefficient (Euler number) leading to lower pressure losses. For most cases where high separation efficiency at moderate pressure drop is required the optimum inlet angle is in the range 10–15°.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-59743 (URN)10.1016/j.powtec.2016.09.050 (DOI)000390732000006 ()2-s2.0-84989182792 (Scopus ID)
Note

Validerad; 2016; Nivå 2; 2016-10-14 (andbra)

Available from: 2016-10-14 Created: 2016-10-14 Last updated: 2018-09-13Bibliographically approved
Misiulia, D., Elsayed, K. & Andersson, A. G. (2017). Geometry optimization of a deswirler for cyclone separator in terms of pressure drop using CFD and artificial neural network. Separation and Purification Technology, 185, 10-23
Open this publication in new window or tab >>Geometry optimization of a deswirler for cyclone separator in terms of pressure drop using CFD and artificial neural network
2017 (English)In: Separation and Purification Technology, ISSN 1383-5866, E-ISSN 1873-3794, Vol. 185, p. 10-23Article in journal (Refereed) Published
Abstract [en]

Four main geometrical parameters of a deswirler (core diameter, number of vanes, height of vanes and leading edge angle) for cyclone separators have been optimized using CFD and artificial neural network. The results indicated that the most significant geometrical parameters of the deswirler are the number of vanes, the vane angle and the vane height. A new optimized deswirler geometry was obtained using the genetic algorithms and its effects on the flow field, pressure losses and cyclone collection efficiency were numerically investigated. The deswirler positively affects the flow field within a cyclone. It dramatically reduces tangential velocities in the vortex finder and only slightly (by 4.5%) decreases maximum tangential velocities in the separation zone. The deswirler also reduces the length of the inner vortex, redistributes uniformly axial velocities at the vortex finder outlet and prevents backward flow. Additionally, the deswirler converts the dynamic energy of the swirling flow into pressure and allows pressure recovery. It reduces pressure losses in the vortex finder by 95.67% that leads to 43.17% reduction in total pressure drop and slightly decreases the separation efficiency for some particle diameters, increasing the cyclone cut size from 1.5 to 1.72 μm.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-63302 (URN)10.1016/j.seppur.2017.05.025 (DOI)000404310900002 ()2-s2.0-85019371517 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-05-29 (rokbeg)

Available from: 2017-05-10 Created: 2017-05-10 Last updated: 2018-07-10Bibliographically approved
Misiulia, D., Andersson, A. G. & Lundström, S. (2017). Large Eddy Simulation Investigation of an Industrial Cyclone Separator Fitted with a Pressure Recovery Deswirler. Chemical Engineering & Technology, 40(4), 709-718
Open this publication in new window or tab >>Large Eddy Simulation Investigation of an Industrial Cyclone Separator Fitted with a Pressure Recovery Deswirler
2017 (English)In: Chemical Engineering & Technology, ISSN 0930-7516, E-ISSN 1521-4125, Vol. 40, no 4, p. 709-718Article in journal (Refereed) Published
Abstract [en]

A cyclone fitted with a deswirler of original design has been investigated by means of large eddy simulation. Installation of the deswirler reduces significantly the positive static pressure near the wall as well as the negative static pressure in the central region. It also decreases the maximum tangential velocities in the main separation zone. The deswirler enables a substantial reduction of the backward flow at the gas outlet and a more uniform distribution of the axial velocities at the gas outlet. It also considerably reduces pressure losses in the vortex finder lowering the cyclone pressure drop by almost about one third but it deteriorates the collection efficiency of particles with diameters of less than 8 µm, thus increasing the cut size.

Place, publisher, year, edition, pages
John Wiley & Sons, 2017
National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-62509 (URN)10.1002/ceat.201600505 (DOI)000397575600011 ()2-s2.0-85015181315 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-03-27 (rokbeg)

Available from: 2017-03-15 Created: 2017-03-15 Last updated: 2018-09-14Bibliographically approved
Misiulia, D., Andersson, A. & Lundström, S. (2015). Computational Investigation of an Industrial Cyclone Separator with Helical-Roof Inlet (ed.). Paper presented at . Chemical Engineering & Technology, 38(8), 1425-1434
Open this publication in new window or tab >>Computational Investigation of an Industrial Cyclone Separator with Helical-Roof Inlet
2015 (English)In: Chemical Engineering & Technology, ISSN 0930-7516, E-ISSN 1521-4125, Vol. 38, no 8, p. 1425-1434Article in journal (Refereed) Published
Abstract [en]

An industrial cyclone separator with helical-roof inlet TsN-11 has been numerically investigated as to pressure and flow field, pressure drop, fractional efficiency, and particle trajectories inside the cyclone. The turbulence was modeled with Reynolds stresses and large eddy simulations (LES) based on three different subgrid-scales (SGS). The results with the different setups were compared to experimental data from previous studies. For a proper calculation of the flow field, LES combined with a dynamic SGS model was used for predicting cyclone performance. Individual particles were tracked through the unsteady flow field using the Lagrangian approach. The results of the numerical calculations of the tangential and axial velocity, pressure drop, and cut size are in good agreement with experimental measurements.

National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-9330 (URN)10.1002/ceat.201500181 (DOI)000358543500016 ()2-s2.0-84937855165 (Scopus ID)7ee86c4a-2c93-4066-bb30-99e83b75b958 (Local ID)7ee86c4a-2c93-4066-bb30-99e83b75b958 (Archive number)7ee86c4a-2c93-4066-bb30-99e83b75b958 (OAI)
Note
Validerad; 2015; Nivå 2; 20150527 (stlu)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Misiulia, D., Andersson, A. & Lundström, S. (2015). Effects of the inlet angle on the flow pattern and pressure drop of a cyclone with helical-roof inlet (ed.). Paper presented at . Chemical engineering research & design, 102, 307-321
Open this publication in new window or tab >>Effects of the inlet angle on the flow pattern and pressure drop of a cyclone with helical-roof inlet
2015 (English)In: Chemical engineering research & design, ISSN 0263-8762, E-ISSN 1744-3563, Vol. 102, p. 307-321Article in journal (Refereed) Published
Abstract [en]

The effects of inlet angle on the flow pattern and pressure drop in cyclones have been numerically investigated using Large Eddy Simulations with the dynamic Smagorinsky-Lilly subgrid-scale. Five cyclones with helical-roof inlets of different inlet angles and five cyclones with tangential inlets of different inlet heights at the same other geometric dimensions are considered. The results show that, increasing the inlet angle as well as the inlet height (inlet area) decreases the absolute values of positive (close to the cyclone wall) and negative (in the central region) static pressure and tangential velocity in the cyclone body that will probably reduce the collection efficiency. Also, increasing the inlet angle reduces the gas flow rates along the cyclone axis in both downward (outer) and upward (inner) vortices and increases the maximum radial velocity under the vortex finder that can enhance the number of small particles entrained by the gas flow and transferred from that region into the vortex finder and negatively affect the overall collection efficiency. The cyclone pressure drop is mainly generated by the losses in the cyclone body (under the vortex finder) and in the vortex finder. There is a significant decrease in pressure drop with increase of inlet angle. Based on the simulations an expression for the dimensionless pressure drop normalized by the inlet velocity for the cyclone with helical-roof inlet of different inlet angles is derived. Cyclones with helical-roof inlets have a higher aerodynamic efficiency as compared to cyclones with tangential inlets, and the highest aerodynamic efficiency was reached with an inlet angle of 20°.

National Category
Fluid Mechanics and Acoustics
Research subject
Fluid Mechanics
Identifiers
urn:nbn:se:ltu:diva-10768 (URN)10.1016/j.cherd.2015.06.036 (DOI)000362615700028 ()2-s2.0-84941952387 (Scopus ID)99f8bb3e-6376-4ca0-876f-70543a46b19f (Local ID)99f8bb3e-6376-4ca0-876f-70543a46b19f (Archive number)99f8bb3e-6376-4ca0-876f-70543a46b19f (OAI)
Note
Validerad; 2015; Nivå 2; 20150629 (stlu)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-6028-4311

Search in DiVA

Show all publications