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1
Content available A critical review of models used in numerical simulation of electrostatic precipitators
100%
Feng Z. , Long Z. , Adamiak K.
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tom nr 4
9--17
EN
The electrostatic precipitators (ESP) have been drawing more and more attention due to their high efficiency and low costs. Numerical simulation is a powerful, economical and flexible tool to design ESP for industry applications. This review summarizes the available numerical models to simulate different physical processes in ESP, including ionized electric field, air flow, particle charging and motion. It has been confirmed that the available models could provide acceptable results and the computing requirements are affordable in industry applications. The coupling between different physical processes can also be considered in simulation. However, there are still some problems not solved, such as selection of a suitable turbulence model in EHD simulation and the coupling criteria. The future study should focus on these issues. This review also includes new types of ESP developed in recent years, such as dielectric barrier discharge (DBD) ESP and corona assisted fibrous filter. These new types of ESP have had high efficiency and low energy consumption. Even though nearly all new ESP types can be modeled using the available numerical models, the most challenging issue is the DBD simulation.
PL
Elektrofiltry są obiektem nieustającej uwagi ze względu na ich wysoką sprawność i niski koszt. Symulacja numeryczna jest bardzo skutecznym, ekonomicznym i elastycznym narzędziem przy projektowaniu przemysłowych elektrofiltrów. Ten artykuł podsumowuje dostępne modele numeryczne do symulacji różnych procesów fizycznych występujących w elektrofiltrach, włączając zjonizowane pole elektryczne, przepływ powietrza, ładowanie cząstek i ich trajektorie. Zostało potwierdzone, że dostępne modele mogą dostarczyć zadowalających wyników nawet używając sprzętu komputerowego dostępnego w zastosowaniach przemysłowych. Wzajemne sprzężenia między różnymi procesami fizycznymi mogą być analizowane podczas symulacji. Ciągle istnieją jednak problemy nierozwiązane, na przykład wybór odpowiedniego modelu turbulencji przeplywu gazu albo kryteriów sprzężeń. Przyszłe badania powinny skoncentrować się na ich rozwiązaniu. Ten przegląd omawia też nowe rodzaje elektrofiltrów zaproponowanych w ostatnich latach, na przykład elektrofiltry oparte na wyładowaniach z barierą dielektryczną albo wspomagane wyładowaniem koronowym filtry włókniste. Te nowe typy elektrofiltrów mają wysoką sprawność i niski pobór energii. Jeśli nawet prawie wszystkie nowe typy elektrofiltrów mogą być modelowane z użyciem istniejących modeli numerycznych, najtrudniejsze jest modelowanie wyładowania z barierą dielektryczną.
2
Predicting current and future invasion of Solidago canadensis: a study from China
100%
Xu Z. , Peng H. , Feng Z. , Abdulsalih N.
Polish Journal of Ecology
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2014
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tom 62
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nr 2
EN
Solidago canadensis, which is native to North America, is considered to be the most widespread invasive alien plant. The invasion of Solidago canadensis in China has resulted in serious environmental problems. Therefore, understanding the relationship between the geographical distribution of S. canadensis and bioclimatic variables, and then predicting the potential distribution of this species is essential for management actions and practices. Although several studies have delineated the potential distribution of S. canadensis in China, how this species would respond to variations in future climatic conditions remains unclear. In the present study, we predicted the potential distribution of S. canadensis under current and future climatic conditions using species distribution models. We also analyzed range shifting of this species under current and future climatic conditions. We arrived at several conclusions. First, the potential distribution of S. canadensis may expand 40% under future climatic condition compare with that of under current condition. Second, mean diurnal range, isothermality, mean temperature of the wettest quarter, mean temperature of the warmest quarter, precipitation of the driest month, and precipitation seasonality (coefficient of variation) are key bioclimatic variables in determine the potential distribution of S. canadensis. Third, expansion of S. canadensis can be partly attributed to the relatively warmer and wetter future bioclimatic condition than current one.
3
Content available Nonlinear vibration signal tracking of large offshore bridge stayed cable based on particle filter
100%
Ye Q. , Feng Z. , Yuan D.
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tom nr 4
70--75
EN
The stayed cables are key stress components of large offshore bridge. The fault detection of stayed cable is very important for safe of large offshore bridge. A particle filter model and algorithm of nonlinear vibration signal are used in this paper. Firstly, the particle filter model of stayed cable of large offshore bridge is created. Nonlinear dynamic model of the stayed-cable and beam coupling system is dispersed in temporal dimension by using the finite difference method. The discrete nonlinear vibration equations of any cable element are worked out. Secondly, a state equation of particle filter is fitted by least square algorithm from the discrete nonlinear vibration equations. So the particle filter algorithm can use the accurate state equations. Finally, the particle filter algorithm is used to filter the vibration signal of bridge stayed cable. According to the particle filter, the de-noised vibration signal can be tracked and be predicted for a short time accurately. Many experiments are done at some actual bridges. The simulation experiments and the actual experiments on the bridge stayed cables are all indicating that the particle filter algorithm in this paper has good performance and works stably.
4
Content available remote Predicting current and future invasion of Solidago canadensis; a study from China
100%
Xu Z. , Peng H. , Feng Z. , Abdulsalih N.
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2014
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tom Vol. 62, nr 2
263--271
EN
Solidago canadensis, which is native to North America, is considered to be the most widespread invasive alien plant. The invasion of Solidago canadensis in China has resulted in serious environmental problems. Therefore, understanding the relationship between the geographical distribution of S. canadensis and bioclimatic variables, and then predicting the potential distribution of this species is essential for management actions and practices. Although several studies have delineated the potential distribution of S. canadensis in China, how this species would respond to variations in future climatic conditions remains unclear. In the present study, we predicted the potential distribution of S. canadensis under current and future climatic conditions using species distribution models. We also analyzed range shifting of this species under current and future climatic conditions. We arrived at several conclusions. First, the potential distribution of S. canadensis may expand 40% under future climatic condition compare with that of under current condition. Second, mean diurnal range, isothermality, mean temperature of the wettest quarter, mean temperature of the warmest quarter, precipitation of the driest month, and precipitation seasonality (coefficient of variation) are key bioclimatic variables in determine the potential distribution of S. canadensis. Third, expansion of S. canadensis can be partly attributed to the relatively warmer and wetter future bioclimatic condition than current one.
5
Content available remote Numerical simulation of spontaneously condensing flows in a plane turbine cascade
100%
Li L. , Li G. , Feng Z.
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tom Vol. 6, No 1
209-216
EN
The low efficiency of wet steam turbine is mainly attributed to wetness losses. To investigate the mechanisms which give rise to these losses, a fully Eulerian model has been developed for calculation of the wet steam flows with spontaneous condensation. In this model, the liquid phase is described with two conservation equations in Eulerian form and coupled with a solver of gas dynamics equations. With such a model, the existing code for simulation of single-phase flows can easily be changed to include wet steam two-phase flows in wet steam turbines. A numerical simulation of condensing flow in a plane turbine cascade is performed, and the numerical results are presented and compared with the experimental results.
6
Content available Underwater Explosion Performance of RDX/AP-based Aluminized Explosives
100%
Xiang D. , Rong J. , He X. , Feng Z.
Central European Journal of Energetic Materials
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2017
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tom Vol. 14, no. 1
60--76
EN
To understand the underwater explosion (UNDEX) performance of RDX/AP-based aluminized explosives, six formulations of the explosives were prepared, with Al content varying from 30% to 55% and ammonium perchlorate (AP) content from 45% to 20%. A series of UNDEX tests that used a 1 kg cylindrical charge was conducted underwater at a depth of 4.7 m. The pressure histories of the shock wave produced at different positions and the bubble periods were measured. The coefficients of the similarity law equation for the shock wave parameters were fitted with experimental data. The effect of the aluminum/oxygen (Al/O) ratio on the performance of the energy output structure for RDX/AP-based aluminized explosives is discussed. The bubble motion during UNDEX was simulated using MSC.DYTRAN software, and the radius-time curves of the bubbles were determined. The results show that AP influences the detonation reaction mechanism of RDX/AP-based aluminized explosives, which causes different UNDEX performances. The bubble energy of the RDX/AP-based aluminized explosive was higher than that of RDX-based and HMX-based aluminized explosives.
7
Content available Provenance-specific climate sensitivity of Pinus massoniana – a multi-environmental trial in subtropical China
88%
Zhang Z. , Jin G. , Feng Z. , Sun L. , Zhou Z.
Dendrobiology
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2021
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tom 85
8
Changes in the pattern of antioxidant enzymes in wheat exposed to water deficit and rewatering
88%
Feng Z. , Jin-Kui G. , Ying-Li Y. , Wen-Liang H. , Li-Xin Z.
Acta Physiologiae Plantarum
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2004
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tom 26
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nr 3
9
Content available Effects of organic cultivation pattern on tomato production: plant growth characteristics, quality, disease resistance, and soil physical and chemical properties
63%
Feng X. , Xu Y. , Liu D. , Peng L. , Dong J. , Yao S. , Feng Y. , Feng Z. , Li F. , Hu B.
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nr 1
EN
Tomato (Solanum lycopersicum L.) is one of the world’s most important cultivated vegetable. In the traditional cultivation methods, the excessive use of pesticides and fertilizers leads to an imbalance of nutrient elements in the soil, an increase in pests and diseases and a decrease in vegetable quality and yield. In the face of increasingly serious environmental and food problems, organic agriculture is considered to be an effective solution. In this experiment, the effects of organic cultivation patterns on the growth, quality, disease resistance in tomatoes, and the physical and chemical properties of soil were studied by different treatments. The results showed that the application of effective microorganisms (EM) bio-organic fertilizer in the cultivation process can significantly improve the yield, quality, and antioxidant enzyme activity of tomato. The use of straw mulching was found to significantly increase the growth, chlorophyll content, transpiration rate, and soluble sugar content of tomatoes. The application of EM bio-organic fertilizer or straw mulching significantly increased the activity of antioxidant enzyme and the expression of LeCHI gene in tomato leaves and enhanced tomato resistance to diseases. Organic production practices were found to significantly improve the soil.
10
Effects of inorganic seed aerosol on the formation of nitrogen-containing organic compounds from reaction of ammonia with photooxidation products of toluene
63%
Xu J. , Huang M. , Feng Z. , Cai S. , Zhao W. , Hu C. , Gu X. , Zhang W.
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nr 1
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