| 1. |
- Sun, Yasong, et al.
(författare)
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Angular-spatial upwind element differential method for radiative heat transfer in a concentric spherical participating medium
- 2022
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Ingår i: Engineering analysis with boundary elements. - : ELSEVIER SCI LTD. - 0955-7997 .- 1873-197X. ; 144, s. 19-30
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Tidskriftsartikel (refereegranskat)abstract
- Radiative intensity with high directional and spatial resolutions can provide abundant useful information for combustion diagnosis systems based on radiative images. In this paper, an angular-spatial upwind element differential method (ASUEDM) is developed to discretize angular direction and spatial domain of radiative transfer equation (RTE) in a spherically participating medium. Because of the strong convection characteristic of radiative transfer equation, an upwind scheme is adopted to suppress the numerical oscillation. Meanwhile, Chebyshev-Gauss-Lobatto nodes are used to minimize the effect of the Runge phenomenon. Unlike conductive or convective boundary conditions, radiative boundary condition is unidirectional boundary condition, and a singularity node exists at the boundary. To deal with this singularity, we propose a discontinuous strategy. Three examples of radiative heat transfer in concentric spheres are chosen to test the capability of ASUEDM. Compared with benchmark solutions, ASUEDM can provide higher accuracy than discrete ordinates method or finite volume method. Besides, ASUEDM can flexibly provide hp convergence rate and achieve high-resolution characterization in angular direction and spatial domain.
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| 2. |
- Liu, Sida, et al.
(författare)
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Improved CO2 separation performance of aqueous choline-glycine solution by partially replacing water with polyethylene glycol
- 2019
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Ingår i: Fluid Phase Equilibria. - : Elsevier. - 0378-3812 .- 1879-0224. ; 495, s. 12-20
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Tidskriftsartikel (refereegranskat)abstract
- Aqueous choline-glycine ([Cho][Gly]) solution is a potential candidate for CO2separation owing to its excellent absorption performance and biodegradability. Moreover, the aqueous solution is easy to volatilize at high temperatures. In this work, H2O was partially replaced with polyethylene glycol (PEG200) and the effect of PEG200 on the CO2 separation performance in [Cho][Gly])/H2O was investigated. The viscosity of [Cho][Gly]/H2O/PEG200 and CO2 solubility in the solution were determined experimentally in the temperature range 308.15–338.15 K at pressures ≤6.5 bar. Further, the measured CO2 solubility was fitted with the reaction equilibrium thermodynamic model and the CO2 desorption enthalpy was estimated. The regeneration performance of [Cho][Gly]/H2O/PEG200 was also evaluated. The results revealed that [Cho][Gly]/H2O/PEG200 has a low CO2desorption enthalpy and high regeneration efficiency. Particularly, [Cho][Gly]/H2O/PEG200 with 30 wt% PEG200 has a high regeneration efficiency of 95%. Owing to its physical-chemical properties and CO2 separation performance, [Cho][Gly]/H2O/PEG200 shows great potential as an absorbent for CO2 separation.
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