In this paper, a numerical simulation is established to model the filling process of atomized natural gas drag reduction agent (DRA) at the pipeline inlet section. The computations are on the basis of the Euler-Lagran...
In this paper, a numerical simulation is established to model the filling process of atomized natural gas drag reduction agent (DRA) at the pipeline inlet section. The computations are on the basis of the Euler-Lagrange method with the standard k-ε turbulence model. The effects of atomizing parameters on the droplets Sauter Mean Diameter (SMD) and the adsorption performance on the wall of pipe are investigated using the validated model. The results show that nozzle diameter and nozzle angle have little effect on the SMD of DRA droplets, whereas the size of the droplets SMD reduces with the increase of atomizing pressure, and the influence of atomizing flow rate is just the opposite.
We demonstrate a typical Mott-Schottky electrocatalyst by ingeniously encasing Co/Co3O4 hetero-nanoparticles within the inner tips of N-doped carbon nanotubes (abbreviated as Co/Co3O4@N-CNTs hereafter) through a facil...
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Safety concerns have perennially impeded the large-scale implementation of high-energy-density storage systems. Nevertheless, because the intrinsic drawbacks of the commercial polyolefin separator are poor thermal sta...
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The influences of the preset angle on the dynamic responses of the typical airfoil section with cubic nonlinear stiffness were investigated under consideration of the aerodynamic flutter onset due to certain angle of ...
The influences of the preset angle on the dynamic responses of the typical airfoil section with cubic nonlinear stiffness were investigated under consideration of the aerodynamic flutter onset due to certain angle of attack. The typical airfoil model with cubic nonlinear stiffness is developed to analyze the plunging and the pitching motions for the airfoil section. Based on the Grossman's quasi steady aerodynamic model, the aerodynamic lift and the moment can be obtained and then the equation of motion for the airfoil section is derived by applying the Lagrange theorem. The effects of the preset angle and the oncoming flow speed on the nonlinear dynamics are analyzed by means of the bifurcation diagram, the frequency-amplitude diagram, the time history, etc. Simulation results show that the preset angle influences the intensity of the vibration, moderate or severe, stable or unstable, even under certain circumstance, the jump and chaos phenomenon occur; and the oncoming flow speed affects the distribution of the vibration energy for the plunging and the pitching motions. The unstable stall region for the responding parameters should be avoided to keep the airfoil safe in engineering practice. Some qualitative and quantitative rules are obtained for the airfoil design and the flutter suppression.
Topological physics has broadened its scope from the study of topological insulating phases to include nodal phases containing band structure singularities. The geometry of the corresponding quantum states is describe...
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The ongoing work investigates the features of Joule heating and convective condition over a magnetohydrodynamic stagnation point flow of (Formula presented.) nanofluid moving across a curved surface. Moreover, mass su...
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The pressure vessel has used a newly designed water seal structure, and the sealed water is from condensation at low hydrogen concentration. To get the condensation capacity of the water seal branch tube under the pre...
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The pressure vessel has used a newly designed water seal structure, and the sealed water is from condensation at low hydrogen concentration. To get the condensation capacity of the water seal branch tube under the pressure vessel normal operation, the experimental loop named WASETEL was constructed, which is aimed at studying the heat transfer during the process of air-steam mixture condensation inside the inclined branch tube at the condition of low air mass fraction. The inner tube is diameter 0.134 m with length 0.68 m which is connected with diameter 1.4 m, high 2.5 m pressure vessel. A canon camera was set to record the images and videos of the condensate height through glass tube in communicating vessel liquidometer. The experiment was conducted under the pressure ranged from 0.2 to 0.6 MPa, air mass concentration ranged from 0.49 to 6.42% and wall subcooling ranged from 11 to 40 K. The test showed HTC (heat transfer coefficient) would sharply deteriorate with the small air fraction, compared with pure steam condensation, about 0.49% mass fraction of the air will reduce heat transfer coefficient by 70–80%. When air concentration is relatively small, those widely used relations can not predict the condensation well, therefore, a new heat transfer empirical correlation with air mass fraction, pressure and subcooling is proposed, covered all the experimental data within the error band ±13%.
The dispatching optimization of power grid is to obtain the greatest benefits on the basis of safe and stable operation of the power grid, which is of great significance for the energy-saving, reliability of the power...
The dispatching optimization of power grid is to obtain the greatest benefits on the basis of safe and stable operation of the power grid, which is of great significance for the energy-saving, reliability of the power grid. Therefore, a multi-objective model of power grid dispatching which considers the heat-power coupling characteristics of CHP units is developed in this study. The economic benefit and minimum wind power abandonment are taken as optimizing targets in the model. Meanwhile, the detail operation characteristics of condensing power plants and CHP units are considered in this model based on off-design models of power plant. Besides, the regional heat load and power load are scheduled together. Finally, the AHP-entropy method is used to obtain the weights of the two optimizing targets of economic benefit and wind power abandonment, and the multi-objective is converted into a single-objective.
Hydrogen (H 2 ) is a clean and environmentally friendly energy carrier. The depletion of fossil fuels makes renewable H 2 production highly desirable. Water reforming of renewable biomass to hydrogen, with a relay of ...
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Hydrogen (H 2 ) is a clean and environmentally friendly energy carrier. The depletion of fossil fuels makes renewable H 2 production highly desirable. Water reforming of renewable biomass to hydrogen, with a relay of natural photosynthesis to biomass, would be an indirect pathway to realize the ideal but extremely challenging photocatalytic overall water splitting to hydrogen, with favorable thermodynamics. Since the seminal work of water reforming of biomass in 1980, great endeavors have been made. Nevertheless, hitherto, the entire kinetic pathway has been elusive, which seriously limits the reforming processes. Using a designed well-organized redox-neutral cleavage of C−C, O−H and C−H bonds enabled by photoelectrocatalysis, here, we show the efficient water reforming of biomass to hydrogen at room temperature, with a yield up to 93 %. The clear insights into the kinetic pathway with oxidation of carbon radicals to carbon cations as the indicated rate-determining step, would cast brightness for efficient and sustainable hydrogen production to accelerate the hydrogen economy.
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