| 1. |
- Grip, Carl Erik, et al.
(författare)
-
Numerical prediction and experimental verification of thermal stratification during holding in pilot plant and production ladles
- 1999
-
Ingår i: ISIJ International. - : Iron and Steel Institute of Japan. - 0915-1559 .- 1347-5460. ; 39:7, s. 715-721
-
Tidskriftsartikel (refereegranskat)abstract
- A 3-dimensional CFD-model has been developed to simulate the natural convection flow in ladles. Qualified measurements of temperature and velocities in 107 and 7 tonne ladles have been made to verify the model. The downward convection flow at the ladle wall has been studied using radioactive isotopes and the thermal stratification has been studied by means of continuous temperature measurements. The experimental techniques are complex and additional numerical simulations have been carried out to study the effect of the measurement technique on the measurement error. The result indicates that the measurements are of sufficient accuracy for the validation. The measurements are compared to predictions from the numerical model. The main conclusion is that the theoretical CFD model gives a very accurate estimation of the temperature distribution during holding.
|
|
| 2. |
- Grip, Carl-Erik, et al.
(författare)
-
Theoretical and practical study of thermal stratification and drainage in ladles of different geometry
- 2000
-
Ingår i: Scandinavian journal of metallurgy. - : Wiley. - 0371-0459 .- 1600-0692. ; 29:1, s. 30-38
-
Tidskriftsartikel (refereegranskat)abstract
- SSAB Lulea, SSAB Oxelosund, MEFOS and Lulea University of Technology have cooperated in developing theoretical models for prediction of thermal stratification and drainage in steel ladles. Predicted results have been verified by measurements done in production ladles with heat weighs of 105 and 200 tonne as well as in a 7-tonne pilot plant ladle. The thermal stratification was measured by thermocouples at different depths. The drainage flow was studied by means of tracer experiments. Numerical simulation models of the steel flow were developed for 7, 105 and 200 tonne steel ladles. The agreement between predictions and measurements was found to be good. The conclusion is that CFD simulation gives a good prediction of stratification and drainage flows in production ladles.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Apleberger, Lennart, et al.
(författare)
-
Byggandets industrialisering : nulägesbeskrivning
- 2007
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapporten belyser definitionsfrågor samt olika förutsättningar och utgångspunkter som behöver beaktas då man diskuterar industrialisering av byggandet. En genomgång av utvecklingsläget i byggbranschen redovisas inklusive en internationell utblick samt forskningsinsatser och utbildning. Industrialiseringsgraden och implementeringsnivån har bedömts för tio olika svenska koncept. I rapporten föreslås också prioriterade områden för fortsatta utvecklingssatsningar.
|
|
| 6. |
|
|
| 7. |
- Jonsson, Patrick, et al.
(författare)
-
Smoothed Particle Hydrodynamic Simulation of Hydraulic Jump using Periodic Open Boundaries
- 2016
-
Ingår i: Applied Mathematical Modelling. - : Elsevier BV. - 0307-904X .- 1872-8480. ; 40:19-20, s. 8391-8405
-
Tidskriftsartikel (refereegranskat)abstract
- The natural phenomena hydraulic jump that is commonly used in spillways as an energy dissipater coupled to hydropower applications has been investigated with Smoothed Particle Hydrodynamics. A new approach was applied based on a periodic open boundary condition. The model consisted of a tank, a gate, a stilling basin and periodic open boundaries at each end of the computational domain. The tank provided a hydraulic head and in turn a specific flow through the gate, and a downstream condition in terms of a depth for the jump. The gate elevation had a major impact and was calibrated to ensure a correct and stable flow rate, when compared to experiments. With the proper flow rate, the position of the jump toe was significantly improved. The jump toe oscillated with a frequency in good agreement with experimental findings found in the literature and the oscillation amplitude increased with Froude number. However, for high Froude number cases the position was still too close to the gate but could be improved by including a correction based on the length of the jump. The depths in both the super- and subcritical zones was in good agreement with experiments and previous numerical studies. Furthermore, the Froude number was in-line with the definition of super- and subcritical flows.
|
|
| 8. |
|
|
| 9. |
- Jonsson, Patrick, et al.
(författare)
-
Smoothed particle hydrodynamics modeling of hydraulic jumps
- 2011
-
Ingår i: Particle-based Methods – Fundamentals and Applications. - Barcelona : International Center for Numerical Methods in Engineering (CIMNE). - 9788489925670 ; , s. 490-501
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This study focus on Smoothed Particle Hydrodynamics (SPH) modeling of twodimensional hydraulic jumps in horizontal open channel flows. Insights to the complex dynamics of hydraulic jumps in a generalized test case serves as a knowledgebase for real world applications such as spillway channel flows in hydropower systems. In spillways, the strong energy dissipative mechanism associated with hydraulic jumps is a utilized feature to reduce negative effects of erosion to spillway channel banks and in the old river bed. The SPH-method with its mesh-free Lagrangian formulation and adaptive nature results in a method that handles extremely large deformations and numerous publications using the SPH-method for free-surface flow computations can be found in the literature. Hence, the main objectives with this work are to explore the SPH-methods capabilities to accurately capture the main features of a hydraulic jump and to investigate the influence of the number of particles that represent the system. The geometrical setup consists of an inlet which discharges to a horizontal plane with an attached weir close to the outlet. To investigate the influence of the number of particles that represents the system, three initial interparticle distances were studied, coarse, mid and fine. For all cases it is shown that the SPH-method accurately captures the main features of a hydraulic jump such as the transition between supercritical- and subcritical flow and the dynamics of the highly turbulent roller and the air entrapment process. The latter was captured even though a single phase was modeled only. Comparison of theoretically derived values and numerical results show good agreement for the coarse and mid cases. However, the fine case show oscillating tendencies which might be due to inherent numerical instabilities of the SPH-method or it might show a more physically correct solution. Further validation with experimental results is needed to clarify these issues.
|
|
| 10. |
|
|
