Mathematical simulation of carbon material burnup in stationary high-pressure air flow

2018 ◽  
Author(s):  
В.В. Горский ◽  
◽  
А.В. Мельковская ◽  
Keyword(s):  
High Pressure ◽  
Mathematical Simulation ◽  
Carbon Material ◽  
Air Flow

Nitrogen-Doped Carbon Material As the Electrocatalyst for Oxygen Reduction Reaction in Rechargeable Zinc-Air Flow Batteries

2020 ◽  
Vol MA2020-01 (3) ◽  
pp. 502-502
Author(s):  
Fatemeh Shakeri Hosseinabad ◽  
Samantha Luong ◽  
Mohammad Javad Parnian ◽  
Ashutosh Kumar Singh ◽  
Viola Ingrid Birss ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Carbon Material ◽  
Air Flow ◽  
Reduction Reaction ◽  
Nitrogen Doped ◽  
Flow Batteries ◽  
Nitrogen Doped Carbon

Drought Events and Causes in North China in 2018

2020 ◽  
Author(s):  
Jianying Feng ◽  
Yu Zhang ◽  
Suping Wang
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Inner Mongolia ◽  
Northeast China ◽  
North China ◽  
Air Flow ◽  
Liaoning Province ◽  
Severe Drought ◽  
Pressure Ridge ◽  
Moderate Drought

<p>In 2018, severe meteorological drought occurred in the southwest of Northeast China, the  east-central of Inner Mongolia and the east of North China. Drought shows obvious regional and stage nature .In early March, mild to moderate drought appeared in North China, followed by severe drought in parts of northern and eastern of Hebe province. After the middle of April, the drought was alleviated obviously, and the drought in the southwest of Northeast China began to show signs. In  early May, there was mild to moderate drought in the central and eastern part of Inner Mongolia, and the drought in Northeast China developed. From June to early August, severe drought and above occurred in parts of Liaoning province , Inner Mongolia and North China. In mid-August, in addition to Liaoning province and North China, there were scattered light to moderate drought, drought relief in the northern China. In early September, the drought in North China increased and the range spread northward, and there were droughts of different degrees in the whole North China.In winter, there is only mild drought in North China.</p><p>The drought in this region has affected the agricultural production in different degrees. Spring sowing is blocked in the east of Inner Mongolia and the west of Northeast China, and high temperature in summer leads to the development of drought, corn and rice and other crops are adversely affected.</p><p>From spring to autumn, the precipitation in most parts of the drought disaster  area is less than 10-40%, and the temperature is higher than 1-2 ℃. The lack of precipitation and abnormal high temperature accelerated the loss of surface water, which resulted in the occurrence of drought in this area.</p><p>In spring of 2018, the middle and high latitudes are generally controlled by flat air flow, which is not conducive to the establishment of trough ridge, making the northern dry area lack of favorable precipitation conditions; in summer and autumn, the existence of Baikal Lake high-pressure ridge, resulting in circulation patterns that are not conducive to the precipitation conditions in the northern dry area. Among them, the obvious flat air flow in spring and the obvious high pressure ridge in summer are the main reasons for the outstanding drought in spring and summer in the northern arid area.</p>

On the Variation of the Polytropic Exponent in a High Pressure Fan Impeller

2016 ◽  
Vol 841 ◽  
pp. 286-291
Author(s):  
Andrei Dragomirescu
Keyword(s):  
High Pressure ◽  
Variable Exponent ◽  
Air Flow ◽  
Numerical Results ◽  
Strong Variation ◽  
Polytropic Process ◽  
Two Stages ◽  
Spiral Casing ◽  
Polytropic Exponent

Fan impellers are usually designed considering that the pumped air is incompressible and homogeneous, i.e. its density remains constant. When the incompressibility hypothesis can lead to significant errors, as in the case of high pressure fans, the analysis of the air flow can be made by considering that the air undergoes a polytropic process of constant polytropic exponent. In this paper, the concept of polytropic process of variable exponent depending on impeller radius is introduced, in order to better approximate the phenomena that take place inside blade passages. Numerical results obtained for an impeller of a high pressure fan without spiral casing suggest that the pumped air undergoes two different processes: an expansion in the first part of the impeller and the usual compression in the second part. The two processes are reflected in the strong variation of the polytropic exponent, which shows a vertical asymptote where the change of the process takes place. The results also suggest that high pressure fan impellers could consist of two stages, each stage being designed according to the process that takes place inside it: expansion or compression.

scholarly journals Structural and construction design of the system and structures of the supply and distribution of air in the treatment of waste

Vestnik MGSU ◽  
2019 ◽  
pp. 118-125
Author(s):  
Danila V. Zelentsov ◽  
Konstantin L. Chertes ◽  
Olga V. Tupitsyna
Keyword(s):  
High Pressure ◽  
Organic Matter ◽  
Contaminated Soils ◽  
Air Flow ◽  
Gas Flows ◽  
Aeration Zone ◽  
Composting Process ◽  
Aeration System ◽  
Decomposition Of Organic Matter ◽  
Forced Aeration

Introduction. Neutralization methods (including composting) are widely used in the technologies of chemical and biothermal oxidation of organic matter. A promising method of waste management is their biothermal composting using controlled gas flows. The methods of process intensification are described: the introduction of inoculating additives, increasing the homogeneity of the mixture, recycling of composts, natural and forced low-pressure and high-pressure aeration, and several others. One example of the implementation of these technologies is the disposal of oil-contaminated soils. Materials and methods. The description of the implemented complexes of biothermal composting of oil-contaminated soils: functional zoning, design solutions. The main functional zones are shown: input control section, intermediate placement area, continuous forced aeration zone (inoculation), periodic forced aeration zone (stacked cavalier biodegradation), and natural aeration zone without mixing (ripening zone). The main element of the complex is the combined aeration system (forced from blower devices and natural mechanical mixing). The expediency of using high-pressure forced aeration to intensify the composting process is shown. Results. The developed mode of operation of the aeration system of the composted mass is described: the initial process of incomplete oxidation of organic matter in stacks of inoculation with a constant air flow and the final decomposition of organic matter with a periodic air flow. The constructive design of the high-pressure forced aeration system used to intensify the composting process is given. Aerobic biothermal composting is performed in aerated piles, which are formed on sites with a waterproof coating. Aeration, necessary to accelerate the decomposition of organic matter in the composts, is carried out in natural (mixing with a ladle) and artificial (purging) conditions. For purging use a system of perforated pipes and blower station. Describes measures to protect pipelines (ducts) from aggressive environmental exposure and increase their service life, to ensure the efficiency of the aeration system in an emergency. Conclusions. The possibility of practical implementation of gas flow control technology in the design, construction and operation of biothermal treatment of waste is shown. The implementation of the projects described in the article showed the need to create a generalized mathematical model that would describe in general terms the behavior of gas flows in heterophase wastes.

scholarly journals Fluid mechanical valving of air flow in bird lungs

1988 ◽  
Vol 136 (1) ◽  
pp. 1-12 ◽  
Author(s):  
D. O. Kuethe
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Pressure Difference ◽  
Air Flow ◽  
Low Pressure ◽  
Physical Models ◽  
Unidirectional Flow ◽  
Air Sacs ◽  
Caudal Portion ◽  
Flow Through

The unidirectional flow through the gas-exchanging bronchi of bird lungs is known to be effected by (1) the structure of the major bronchi and (2) a pressure difference between the cranial and caudal air sacs. To study the effects of bronchial structure, simple physical models of bird lungs were constructed. They suggested that, to achieve unidirectional flow, air in the caudal portion of the primary bronchus must be directed towards the orifices of the mediodorsal bronchi. To study the effect of air sac pressures, a controllable pressure difference was produced between the air sac orifices of fixed duck lungs. The cranial orifices had a higher pressure than the caudal ones during inhalation and vice versa during exhalation. There was a set of pressure differences for which the paleopulmo received the same flow rate during inhalation as during exhalation. High pressure differences caused more flow in the paleopulmo during exhalation than during inhalation; low pressure differences had the converse effect.

Cooling by Means of Minichannel Air-flow at High Pressure Ratio

2004 ◽  
Vol 2004.3 (0) ◽  
pp. 21-22
Author(s):  
Kazuo KARA ◽  
Masahiro INOUE ◽  
Masato FURUKAWA
Keyword(s):  
High Pressure ◽  
Pressure Ratio ◽  
Air Flow ◽  
High Pressure Ratio

Numerical simulation of air flow field in high-pressure fan with splitter blades

2008 ◽  
Vol 2 (4) ◽  
pp. 438-442
Author(s):  
Jianfeng Li ◽  
Junfu Lu ◽  
Hai Zhang ◽  
Qing Liu ◽  
Guangxi Yue
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
Flow Field ◽  
Air Flow

Numerical Simulation of 3D Flow in Rotation Cup of Rotor Spinning

2011 ◽  
Vol 80-81 ◽  
pp. 1145-1149
Author(s):  
Xi Wei Yang ◽  
Hong Li Chen ◽  
Zhen Yu Wu ◽  
Shi Fu Xu
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
Flow Field ◽  
Slip Plane ◽  
Air Flow ◽  
Reverse Direction ◽  
3D Flow ◽  
Rotor Spinning ◽  
Simulation Results

To make design of rotation cup device more reasonable, the air-flow-field in rotation cup should be analyzed. Numerical simulation is conducted on 3D flow in rotation cup of rotor spinning with Fluent and the simulation results reveal the airflow characteristics as: the vortex is generated in rotation cup and the airflow speed decreases gradually on slip plane; the airflow in the type of V accumulation groove is more intensive and a little faster than that in the type of U accumulation groove in the same condition; there exist two strands of reverse direction airflow in accumulation groove; there exist two high pressure regions on slip plane and accumulation groove.

INTENSIFICATION OF AERATION PROCCES IN TECHNOLOGICAL SCHEMES OF WASTEWATER TREATMENT

2016 ◽  
Vol 6 (2) ◽  
pp. 27-30
Author(s):  
Vyacheslav N. ZENTSOV ◽  
Irina V. LAPSHAKOVA ◽  
Ural R. ISLAMOV
Keyword(s):  
Mass Transfer ◽  
High Pressure ◽  
Wastewater Treatment ◽  
Air Flow ◽  
Sewage Treatment ◽  
Minimum Cost ◽  
Low Pressure ◽  
Resource Conservation ◽  
Treatment Facilities

The problems of resource conservation in the reconstruction of sewage treatment facilities were studied. The characteristic of modern aerators is given. It provides an assessment of the effectiveness of low pressure aeration in modern conditions with the use of new designs aerators and high-pressure fans. The results of calculations for immersion aerator range of 0.5 to 6 m in the total air flow, mass transfer and capacity characteristics are given. It is shown that the minimum cost of power comes with a depth of placement of aerators, equal to one meter. It has been observed that a decrease in the depth of immersion aerator is reduced. It is noted that such a design facilitates access to aerators during operation. The advantage of the high-pressure fans in comparison with low-pressure, nonadjustable blower is shown.

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