scholarly journals Influence of air flow speed on main characteristics of nonstationary pulsed discharge, created with help of stationary power source

2018 ◽  
Vol 1112 ◽  
pp. 012002
Author(s):  
V M Shibkov
Keyword(s):  
Air Flow ◽  
Power Source ◽  
Flow Speed ◽  
Pulsed Discharge

scholarly journals Approbation of the Laser Doppler Anemometer Lad-08 on the Secondary Standard Test Rig for Air Flow Speed

2020 ◽  
Vol 1675 ◽  
pp. 012082
Author(s):  
I K Kabardin ◽  
V G Meledin ◽  
S V Dvoinishnikov ◽  
V A Pavlov ◽  
G V Bakakin ◽  
...  
Keyword(s):  
Air Flow ◽  
Flow Speed ◽  
Standard Test ◽  
Laser Doppler Anemometer ◽  
Laser Doppler ◽  
Secondary Standard ◽  
Test Rig

Virtual Height Aided Solar Chimney: A New Design

2011 ◽  
Author(s):  
Khaled I. E. Ahmed ◽  
Ali K. Abdel-Rahman ◽  
Mahmoud Ahmed ◽  
Wael M. Khairaldien
Keyword(s):  
Electric Power ◽  
Co2 Emissions ◽  
Conversion Efficiency ◽  
Numerical Study ◽  
Air Flow ◽  
Flow Speed ◽  
Numerical Results ◽  
Solar Chimney ◽  
Virtual Height ◽  
Wide Range

Renewable energy source deployment is growing rapidly as it reduces CO2 emissions and increases diversity and security of supply. Solar chimney (SC) is a promising large-scale power technology, which absorbs solar radiation and converts parts of solar energy into electric power free of CO2 emissions. A major problem of Solar Chimney Power Plant (SCPP) is its low conversion efficiency as determined by the thermal performance of the system. However, the conversion efficiency of SCPP significantly increases with the SC height increase. The current paper proposes a new design of a virtual height aided solar chimney. In this new system the solar chimney is aided with a passive cooling system at the top of the chimney and a passive solar heater at its base to virtually mimic larger heights of the chimney. The new design has been simulated numerically for development and optimization. The numerical study is done in two stages to examine this concept. In the first stage, numerical results are obtained for the effect of the chimney height on the inside air flow speed. Then, in the second stage, the effect of decreasing the temperature at the chimney exit and the effect of increasing the temperature at the chimney base on the air flow speed are examined separately for small chimney heights. Then the combined effect of the two actions is investigated at a wide range of chimney heights. The numerical results have shown that the localized base heating and exit cooling have significantly enhanced the chimney performance for chimney heights up to 500m. A chimney with height of 300m gains an increase in the air velocity more than 25% due to the heating and cooling actions. Virtual height aided Chimney with original height of 300m acts similarly to a conventional chimney with height of 500m due to the effect of base heating and exit cooling actions. This air flow velocity increase reflects 100% increase in the expected generated electric power. Further detailed results are presented and discussed.

EMS-0.1/60: Standard test rig for air flow speed

2010 ◽  
Vol 71 (11) ◽  
pp. 2483-2490 ◽  
Author(s):  
A. I. Samoilenko ◽  
V. K. Maskaev
Keyword(s):  
Air Flow ◽  
Flow Speed ◽  
Standard Test ◽  
Test Rig

scholarly journals JUSTIFICATION OF AIR FLOW SPEED IN THE OXIDATION AREA OF A GASIFIER IN CASE OF STRAW PELLETS USING

2020 ◽  
pp. 37-44
Author(s):  
Savelii Kukharets ◽  
Gennadii Golub ◽  
Oleh Skydan ◽  
Yaroslav Yarosh ◽  
Mikolai Kukharets
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Flow Speed ◽  
Loss Coefficient ◽  
Total Loss ◽  
Oxidation Zone ◽  
Bernoulli Equation ◽  
Air Flow Rate ◽  
Average Speed ◽  
Flow Length

On the basis of the Bernoulli equation the dependence for determining the air flow rate in the oxidation zone of the gasifier was obtained. The obtained dependence makes it possible to theoretically establish the average speed and diameter of the air flow depending on the flow length. To check and clarify the obtained dependence for determining the air flow rate in the oxidation zone, the value of the total loss coefficient of the air flow rate in the volume of straw pellets, which are used as fuel for the gasifier, is experimentally established.

scholarly journals MATHEMATICAL MODELING OF PROCESSES OF SEPARATION OF COMPONENTS OF GRAIN MATERIAL IN THE COMBINED VIBRATION-AIR SEPARATOR

2020 ◽  
pp. 51-59
Author(s):  
Sergey Stepanenko ◽  
Borys Kotov
Keyword(s):  
Mathematical Modeling ◽  
Equations Of Motion ◽  
Air Flow ◽  
Flow Speed ◽  
Material Point ◽  
Experiment Planning ◽  
Theoretical Studies ◽  
Fluidized Layer ◽  
Aerodynamic Properties ◽  
Air Separator

Development of a mathematical model and calculated analytical dependencies for determining the trajectories and parameters of grain movement in a vibro-fluidized layer of grain material components under the action of a pulsating air flow. They are based on the methods of deterministic mathematical modeling and theoretical mechanics based on the equations of motion of a material point at a variable air flow speed and the action of a pulsating air flow. Theoretical studies were carried out using the methods of mathematical analysis and modeling. The research results were processed using elements of the theory of probability and mathematical statistics using software packages; to determine the rational parameters of the process, the method of statistical experiment planning was used. A mathematical description of the motion of the grain material particles in a combined vibration-air separator under the action of a pulsating air flow of variable speed is given. The trajectories of motion of particles with different sizes are obtained. The obtained equation of motion of a particle under the influence of a pulsating air flow makes it possible to determine the dependence of the speed of movement of the material in a vibro-fluidized layer of grain material on a number of factors: the geometric parameters of the sieve-free sieve, the feed angle of the material, the initial kinematic mode of the material, the index of the kinematic mode of the sieve-free sieve, as well as the coefficient of windage of the grain. On the basis of theoretical studies, the possibility of separating particles of grain material into fractions according to aerodynamic properties with vibropneumatic loading of grain into the channel has been determined. The use of a pulsating air flow as a separating carrier, and taking into account the deflecting forces, made it possible to significantly increase the splitting of the trajectories and the criterion for dividing the grain into fractions.

scholarly journals Air Heat Pump in Wind Power

2020 ◽  
Vol 63 (3) ◽  
pp. 264-284
Author(s):  
L. I. Gretchikhin ◽  
A. I. Hutkouski
Keyword(s):  
Heat Pump ◽  
High Speed ◽  
Conversion Coefficient ◽  
Air Flow ◽  
Experimental Studies ◽  
Energy System ◽  
Flow Speed ◽  
Back Side ◽  
Electric Generator ◽  
Propeller Blades

An experimental facility has been developed and manufactured to study the disruptive flow in an air heat pump. The propeller of the heat pump does not produce pulling or pushing forces. The external air flow is created by a high speed propeller perpendicular to the plane of rotation of the heat pump propeller and acts as a ventilator. Herewith, a disruptive flow in the back side of the heat pump propeller is being created and conditions for converting the thermal component of the ventilator air flow into electrical energy by an electric power generator are realized. An aerodynamic model of the flow around the propeller blades of the heat pump in mutually perpendicular airflow has been developed. Experimental studies of the operating propeller as a heat pump, taking into account the friction during rotation of the rotor in the stator of the electric generator, were carried out. In order for the air heat pump to perceive the impacting air flow from the ventilator, it must rotate with minimal power. As a result, for two standard twin-bladed propellers mounted on a 100 W engine under the wind generated by the ventilator which speed is 2.17 m/s the conversion factor was 5.04. As the speed of air flow from the ventilator increased, the  conversion  coefficient  decreased  sharply.  When  placing  the  two  specified  propellers  on a 300 W motor, the minimum pre-rotation power was 5.7 W. In this case, when an air flow speed is of 1.08 m/s, the conversion coefficient reached only 2.93 and also fell sharply with the increase in the air flow speed. When a three-blade propeller with blades was used on a 300 W motor, then situation has changed dramatically. When the motor with a special propeller with a power of 12.1 W was spun and the air flow was formed at a speed of 3.2 m/s, the conversion coefficient was 12.4. With the reduction in the power of the spinup down to 5.9 W and in the speed of the air flow created by the ventilator to 1.7 m/s, the conversion coefficient increased to 14.9. The theoretical calculation of heat pump conversion coefficient is confirmed by experimental data. The conditions under which this coefficient reaches its maximum value are set. Computer modeling of different designs of heat pump propeller blades was performed. It is demonstrated that an air heat pump is a complex open energy system.

Optimal Design of Heating and Ventilation for Drying Room Based on Transient CFD Simulation

2013 ◽  
Vol 364 ◽  
pp. 524-528 ◽  
Author(s):  
Si Huang ◽  
Tian Tian Ding ◽  
Chao Yan ◽  
Zi Sheng Wang
Keyword(s):  
Heat Transfer ◽  
Optimal Design ◽  
Temperature Rise ◽  
Cfd Simulation ◽  
Numerical Solutions ◽  
Air Flow ◽  
Heating Time ◽  
Flow Speed ◽  
Drying Time ◽  
Flow And Heat Transfer

Transient air flow and heat transfer in a container-drying room is simulated by using Airpak software in this paper. The transient numerical solutions are obtained for air flow within the drying room including flow speed, pressure, temperature, mean age of air, etc. The analysis focuses on temperature, temperature rise and mean age of air surrounding the container surface with heating time. Drying design is determined by comparing two different ways for heating and ventilation. By means of simulation, it is possible to significantly shorten the drying time of the container corners, and to achieve the purpose of energy saving.

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