scholarly journals From fire whirls to blue whirls and combustion with reduced pollution

2016 ◽  
Vol 113 (34) ◽  
pp. 9457-9462 ◽  
Author(s):  
Huahua Xiao ◽  
Michael J. Gollner ◽  
Elaine S. Oran
Keyword(s):  
Water Surface ◽  
High Efficiency ◽  
Vortex Breakdown ◽  
Surface Boundary ◽  
Laboratory Studies ◽  
Hydrocarbon Flame ◽  
Research Platform ◽  
Reduce Emissions ◽  
Safety Applications ◽  
Oil Spill Remediation

Fire whirls are powerful, spinning disasters for people and surroundings when they occur in large urban and wildland fires. Whereas fire whirls have been studied for fire-safety applications, previous research has yet to harness their potential burning efficiency for enhanced combustion. This article presents laboratory studies of fire whirls initiated as pool fires, but where the fuel sits on a water surface, suggesting the idea of exploiting the high efficiency of fire whirls for oil-spill remediation. We show the transition from a pool fire, to a fire whirl, and then to a previously unobserved state, a “blue whirl.” A blue whirl is smaller, very stable, and burns completely blue as a hydrocarbon flame, indicating soot-free burning. The combination of fast mixing, intense swirl, and the water–surface boundary creates the conditions leading to nearly soot-free combustion. With the worldwide need to reduce emissions from both wanted and unwanted combustion, discovery of this state points to possible new pathways for reduced-emission combustion and fuel-spill cleanup. Because current methods to generate a stable vortex are difficult, we also propose that the blue whirl may serve as a research platform for fundamental studies of vortices and vortex breakdown in fluid mechanics.

A Continuous Desingularized Source Distribution Method Describing Wave–Body Interactions of a Large Amplitude Oscillatory Body

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Aichun Feng ◽  
Zhi-Min Chen ◽  
W. G. Price
Keyword(s):  
Free Surface ◽  
Boundary Conditions ◽  
Water Surface ◽  
Numerical Solutions ◽  
Free Water ◽  
Source Distribution ◽  
Surface Boundary ◽  
Distribution Method ◽  
Collocation Points ◽  
Calm Water

A Rankine source method with a continuous desingularized free surface source panel distribution is developed to solve numerically a wave–body interaction problem with nonlinear boundary conditions. A body undergoes forced oscillatory motion in a free water surface and the variation of wetted body surface is captured by a regridding process. Free surface sources are placed in continuous panels, rather than points in isolation, over the calm water surface, with free surface collocation points placed on the calm water surface. Nonlinear kinematic and dynamic free surface boundary conditions along the collocation points on the calm water surface are solved in a time domain simulation based on a Lagrange time dependent formulation. Compared with isolated desingularized source points distribution methods, a significantly reduced number of free surface collocation points with sparse distribution are utilized in the present numerical computation. The numerical scheme of study is shown to be computationally efficient and the accuracy of numerical solutions is compared with traditional numerical methods as well as measurements.

scholarly journals The Resource Utilization of Water Hyacinth (Eichhornia crassipes [Mart.] Solms) and Its Challenges

Resources ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 46 ◽  
Author(s):  
Weiping Su ◽  
Qingping Sun ◽  
Meisheng Xia ◽  
Zhengshun Wen ◽  
Zhitong Yao
Keyword(s):  
Resource Utilization ◽  
Water Surface ◽  
Eichhornia Crassipes ◽  
Large Scale ◽  
High Efficiency ◽  
Animal Feed ◽  
Water Environment ◽  
Organic Substrates ◽  
River Channels ◽  
Water Transportation

The unchecked growth of Eichhornia crassipes can cause significant harm, including covering of the water surface, depletion of oxygen, clogging of river channels, and promotion of the breeding of flies and mosquitoes. These effects can significantly impact farmland irrigation, water transportation, and human health. However, methods for controlling its growth are not ideal, and control using biological and chemical agents can result in secondary pollution. The utilization of E. crassipes as a resource, for example, as animal feed or organic substrates, can not only turn waste into valuable resources, but it can also solve the problem of its growth, thus bringing about economic and ecological benefits. In this paper, the growth and ecological characteristics of E. crassipes, its nutrient composition, and resource utilization approaches were reviewed. The challenges associated with the large-scale utilization of E. crassipes were also analyzed in order to provide references for the control and resource utilization of the species. Regarding challenges such as the difficulty of cultivation and the high cost of harvesting and dehydrating, it is necessary to investigate the proper water surface and coverage characteristics of E. crassipes cultivation to assure adequate biomass and protect the ecological landscape. It is also necessary to evaluate the effect of E. crassipes cultivation on the health of aquatic ecosystems and the safety of the water environment in order to prevent the significant potential ecological and environmental risks. In addition, developing portable, high-efficiency facilities to promote the effectiveness of harvesting, transportation and dehydration are needed, as well as further improvement in the techniques of utilization and assessment of the economic value.

Wedge-Shaped Shell Structure Impacting a Water Surface

2005 ◽  
Author(s):  
Adrian Constantinescu ◽  
Volker Bertram ◽  
Ion Fuiorea ◽  
Alain Neme
Keyword(s):  
Water Surface ◽  
Surface Velocity ◽  
Convergence Criterion ◽  
Surface Boundary ◽  
Fluid Structure ◽  
Pressure Fields ◽  
Wet Surface ◽  
Peak Pressures ◽  
The Impact ◽  
Asymptotic Formulation

This paper presents a study of fluid structure interaction during the impact of a ship on a water surface. The analysis combines the assumption of small displacements for the ideal fluid and the solid with an asymptotic formulation for accurate pressure evaluation on the wet surface boundary. A fluid-heat analogy is used to obtain the regular displacement, velocity and pressure fields in the fluid domain with ABAQUS/Standard finite element code. PYTHON and FORTRAN languages are also employed to connect fluid and structure data. Two methods are developed. The first method employs a weak fluid-structure coupling. The average discrepancy between our numerical results and experiments was 22% for the peak pressures for conical shell structures. The wet surface velocity was well predicted. The second method (implicit fluid-structure coupling using a convergence criterion) is more accurate. Recent results with an improved, numerical hydrodynamic model based on CFD are also presented.

Development of Controlled Diffusion Airfoils for Multistage Compressor Application

1984 ◽  
Vol 106 (2) ◽  
pp. 271-278 ◽  
Author(s):  
D. E. Hobbs ◽  
H. D. Weingold
Keyword(s):  
High Efficiency ◽  
Boundary Layer Separation ◽  
Surface Boundary ◽  
Standard Series ◽  
Suction Surface ◽  
Surface Boundary Layer ◽  
Controlled Diffusion ◽  
Multistage Compressor ◽  
Mach Numbers ◽  
Inlet Conditions

A series of Controlled Diffusion Airfoils has been developed for multistage compressor application. These airfoils are designed analytically to be shock-free at transonic Mach numbers and to avoid suction surface boundary layer separation for a range of inlet conditions necessary for stable compressor operation. They have demonstrated, in cascade testing, higher critical Mach numbers, higher incidence range, and higher loading capability than standard series airfoils designed for equivalent aerodynamic requirements. These airfoils have been shown, in single and multistage rig testing, to provide high efficiency, high loading capability, and ease of stage matching, leading to reduced development costs and improved surge margin. The Controlled Diffusion Airfoil profile shapes tend to have thicker leading and trailing edges than their standard series counterparts, which lead to improved compressor durability.

scholarly journals Environmental impact assessment of industrial enterprises (on the example of objects of category I,II of environmental impact in the Samarkand region)

2021 ◽  
Vol 265 ◽  
pp. 04025
Author(s):  
Tanzila R. Madjidova ◽  
Gulmira S. Boboeva ◽  
Gulmira F. Keldiyarova
Keyword(s):  
Environmental Impact ◽  
High Efficiency ◽  
New Technologies ◽  
Rolling Stock ◽  
Gas Cleaning ◽  
Industrial Enterprises ◽  
Cleaning Equipment ◽  
Key Sectors ◽  
Reduction Of Emissions ◽  
Reduce Emissions

As a result, the implementation of measures to protect the atmosphere (the use of innovative technologies in the introduction of dust and gas cleaning equipment, the conversion of cars to gaseous fuel, the renewal of rolling stock, the implementation of the state program to reduce emissions), the stabilization of the environment is observed. It is necessary to carry out technical re-equipment of key sectors of the economy, the introduction of new technologies, as well as the stabilization and reduction of emissions of pollutants into the atmosphere. It is recommended to take additional measures to ensure that the amount of pollutants released into the atmosphere as a result of the operation of the facility does not exceed the permissible level, to install dust-collecting equipment that captures dust with high efficiency (up to 99.5%).

THE CYCLONET: A DEVICE FOR PICKING UP OIL SLICKS FROM THE SEA SURFACE

1975 ◽  
Vol 1975 (1) ◽  
pp. 387-394 ◽  
Author(s):  
Jacques Pichon
Keyword(s):  
Water Surface ◽  
Contemporary Problem ◽  
High Efficiency ◽  
Liquid Mixture ◽  
Sea Surface ◽  
Remedial Action ◽  
Power Requirement ◽  
Water Conditions ◽  
Water Surfaces ◽  
Rich Liquid

ABSTRACT Removal of liquid pollutants accidentally released onto water surface is a serious contemporary problem. Efficient remedial action requires that well-designed, reliable equipment be brought to the scene in a matter of hours and that a pollutant-rich liquid mixture be quickly recovered however uncongenial the prevailing weather and water conditions may be. Alsthom-Techniques des Fluides has developed a simple item of equipment for recovering oil slicks from water surfaces, the CYCLONET. Principal features are:a. ready for action at short noticeb. high efficiency: mixture removed contains 80–100% pollutantc. uncomplicated design with no moving parts below water surfaced. operates in rough watere. adaptable to various types of craftf. boat engine the only power requirement.

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