The Influence of Atmospheric and Subsoil Impact on the Evaporation Process During Firefighter’s Events

2021 ◽  
Vol 23 ◽  
pp. 420-433
Author(s):  
Andrzej Polanczyk ◽  
Aleksandra Piechota-Polanczyk ◽  
Małgorzata Majder-Łopatka ◽  
Anna Dmochowska ◽  
Zdzislaw Salamonowicz
Keyword(s):  
Wind Speed ◽  
Tap Water ◽  
Porous Surface ◽  
Evaporation Process ◽  
Surface Evaporation ◽  
Evaporation Intensity ◽  
Porous Surfaces ◽  
Set Up

The influence of sun rays, wind speed, and different type of subsoil on the evaporation process was analyzed. A dedicated experimental set-up for investigation of evaporation process of three liquids (ethanol, petrol and tap water) deposited on glass and sand was created. Results indicated that for porous surfaces wind decreased the amount of evaporated liquids. After substitution of wind with sun rays for porous surface evaporation process increased for ethanol and petrol, respectively. Finally, the influence of both wind and sun rays indicated a 1% and 5% decrease of evaporation intensity for tap water and petrol, respectively. While, a 2% increase of evaporated liquid was observed for ethanol. It was noticed that application of porous surface caused the highest improvement of evaporation process for petrol and tap water, while the lowest for ethanol. Moreover, application of wind together with porous surface increased the intensity of evaporation for all analyzed liquids.

scholarly journals Experimental study on the evaporating progress of hexane lens on immiscible liquid：Spreading and receding

2021 ◽  
Vol 321 ◽  
pp. 01017
Author(s):  
Aiqiang Chen ◽  
Jinghong Yin ◽  
Huiqin Wang ◽  
Bin Liu ◽  
Rachid Bennacer
Keyword(s):  
Evaporation Rate ◽  
Droplet Evaporation ◽  
Immiscible Liquid ◽  
Deionized Water ◽  
Maximum Diameter ◽  
Evaporation Process ◽  
Droplet Spreading ◽  
Minimum Diameter ◽  
Base Solution ◽  
Evaporation Intensity

The change of evaporation liquid on another immiscible liquid has important guiding significance for many applications. In this experiment, the geometric temperature distribution and evaporation rate of n-hexane droplets were observed and recorded by changing the temperature of deionized water. The results show that with the increase of temperature of deionized water-based solution, the maximum diameter of n-hexane droplet spreading after titration increases gradually, while the minimum diameter of n-hexane droplet disappearing decreases gradually. Meanwhile, the evaporation rate of n-hexane droplet is constant during the whole evaporation process. It should also be mentioned that if the base solution is changed from deionized water to a certain concentration of salt solution, the maximum diameter of n-hexane droplet spreading will be reduced, and the evaporation intensity will be relatively reduced. These experimental results will give us a better understanding of the mechanism and characteristics of droplet evaporation.

Meteorological Data Forecast using RNN

2020 ◽  
pp. 905-920
Author(s):  
Stefan Balluff ◽  
Jörg Bendfeld ◽  
Stefan Krauter
Keyword(s):  
Neural Networks ◽  
Wind Speed ◽  
Linear Prediction ◽  
Learning Algorithm ◽  
Meteorological Data ◽  
System Modeling ◽  
Descent Method ◽  
Gradient Descent Method ◽  
Earth System Modeling ◽  
Set Up

Gathering knowledge not only of the current but also the upcoming wind speed is getting more and more important as the experience of operating and maintaining wind turbines is increasing. Not only with regards to operation and maintenance tasks such as gearbox and generator checks but moreover due to the fact that energy providers have to sell the right amount of their converted energy at the European energy markets, the knowledge of the wind and hence electrical power of the next day is of key importance. Selling more energy as has been offered is penalized as well as offering less energy as contractually promised. In addition to that the price per offered kWh decreases in case of a surplus of energy. Achieving a forecast there are various methods in computer science: fuzzy logic, linear prediction or neural networks. This paper presents current results of wind speed forecasts using recurrent neural networks (RNN) and the gradient descent method plus a backpropagation learning algorithm. Data used has been extracted from NASA's Modern Era-Retrospective analysis for Research and Applications (MERRA) which is calculated by a GEOS-5 Earth System Modeling and Data Assimilation system. The presented results show that wind speed data can be forecasted using historical data for training the RNN. Nevertheless, the current set up system lacks robustness and can be improved further with regards to accuracy.

Experimental Study of the Temperature Field Equation in the Leeward Tunnel during Mine Fire Period

2012 ◽  
Vol 588-589 ◽  
pp. 1842-1848
Author(s):  
Wen Cai Wang ◽  
Yu Hong Jiang ◽  
Tao Hou ◽  
Wei Liu ◽  
Yang Lu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Temperature Field ◽  
Field Equation ◽  
Wind Speed ◽  
Stable Phase ◽  
Measuring Point ◽  
Mine Fire ◽  
Mine Roadway ◽  
Set Up

According to the principle of heat transfer, the temperature field equation in the leeward tunnel was set up and the experimental device with a ratio of 1:20 was built. When it happened to fire in roadway, the correctness of the temperature field equation can be verified by the experiment. In experiments, the armored thermocouple and color paperless recorder were used to record the temperature of each measuring point. The S-3-300 pitot tube and YJB-2500 compensation micro-manometer were used to determine the wind speed. When the mine roadway fired, the experiment determined the temperature field equation experiment coefficient of Kc. It showed that in the developing phase of the fire Kc= 15 ~ 20, in the stable phase of the fire Kc= 10 ~ 15, in the failing phase of the fire Kc= 20 ~ 25.

Fluid flow in regions bounded by porous surfaces

1956 ◽  
Vol 234 (1199) ◽  
pp. 456-475 ◽  
Keyword(s):  
Integral Equation ◽  
Porous Surface ◽  
Experimental Conditions ◽  
Porous Tube ◽  
Physical Conditions ◽  
Striking Result ◽  
Through Flow ◽  
Porous Surfaces ◽  
Flow Through ◽  
Measured Distribution

The aerodynamic effects of sucking away boundary layers or blowing air into them through a porous surface have been studied on the assumption that the rate of discharge through the pores is under the control of the experimenter. When all the fluid reaches the field of flow through the pores the pressure at any point in the field depends on the distribution over the porous surface of the flow through it, and the through-flow at any point of it depends on the pressure there. To describe flow of this kind mathematically is difficult and no case seems to have been discussed before. In § 1 a particular case, that of flow through a wedge, cylinder or cone made of a material the resistance of which is proportional to the square of the velocity through it, is treated by means of an integral equation. This equation is solved and the results reduced to a form which lends itself to experimental verification. In § 2 experiments are described in which the physical conditions assumed in the analysis were very nearly attained and the theoretical conclusions then verified. The most striking result was the agreement, to within 1%, between the calculated and the measured discharge of water from a tank through an internal porous tube whose base was an orifice in the bottom. The measured distribution of velocity in the plane of the orifice also agreed with the calculations. Experiments with porous cones also yielded results agreeing with theory when the correct experimental conditions could be satisfied.

Strategy on Improving Lateral Driving Stability of the Automobiles Passing by the Vicinity of A-Shaped Pylon of Zhengxin Yellow River Highway-Railway Bridge in Cross Wind

2011 ◽  
Vol 250-253 ◽  
pp. 1827-1833
Author(s):  
Da Lei Wang ◽  
Ai Rong Chen ◽  
Hui Lin Ai
Keyword(s):  
Wind Speed ◽  
Yellow River ◽  
Driving Safety ◽  
Medium Size ◽  
Railway Bridge ◽  
Complex Flow ◽  
Wind Environment ◽  
Wind Barrier ◽  
Set Up ◽  
Driving Stability

Problem of lateral driving stability of the automobiles passing by the vicinity of pylons of cable-supported bridges in condition of strong cross wind exists obviously because of the alternative wind environment above the deck due to complex flow fluid around the pylon and the deck. Based on numerical wind tunnel technology, the numerical simulation investigation of alternating wind environment above the girder near A-shaped pylon for main span of the steel truss girder cable-stayed bridge of Zhengxin Yellow River Highway-railway Bridge is carried out, considering wind barrier set up on the deck or not. The result shows that the original program has significant effect on wind speed amplification and mutation near the pylon domain in cross wind. Further investigation on wind barrier set up on both sides of the girder section or near the A-shaped pylon along the bridge gives that wind barrier near the A-shaped pylon is useful for reducing wind speed above the leeward deck near the pylon and weakening its mutation. Deeply, taken a medium-size commercial bus as an example, lateral driving stability of the automobiles passing by the leeward lane near A-shaped pylon is discussed through the dynamic response simulation of the vehicle controlled by ideal-driver under cross wind. The results confirms again that the wind barrier near the A-shaped pylon is good for driving safety of vehicles passing by the leeward lanes in vicinity of A-shaped pylon. In all, above work provides technical support for the final implementation of the wind barrier as an engineering measure.

Research on Manufacturing Technology and Heat Transfer Characteristics of Sintered Porous Surface Tubes

2010 ◽  
Vol 97-101 ◽  
pp. 1161-1165 ◽  
Author(s):  
Xue Sheng Wang ◽  
Zheng Bian Wang ◽  
Qin Zhu Chen
Keyword(s):  
Heat Transfer ◽  
Boiling Heat Transfer ◽  
Base Material ◽  
Porous Surface ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Bronze Powder ◽  
New Process ◽  
Porous Surfaces ◽  
Heat Transfers

A new process for manufacturing sintered porous surface tube has been developed. By using this technology, three kinds of sintered porous surface tubes were fabricated, which base material was carbon steel and the sintered layer was bronze powder. And their boiling heat transfer characteristics were investigated experimentally. The experimental results indicated that the boiling heat transfers coefficient and the heat flux of these porous surfaces tubes were increased by 8~14 times and 5~8 times respectively compared with the smooth one. Finally, a new high flux heat exchanger was designed and applied instead of conventional one in a refinery.

Wind-Driven SEIGs for Supplying Isolated Loads Employing DSP Based Power Electronic Controllers

2012 ◽  
Vol 36 (6) ◽  
pp. 739-757 ◽  
Author(s):  
S. Senthilkumar ◽  
N. Kumaresan ◽  
N. Rakesh ◽  
K. Vijayakumar ◽  
M. Subbiah
Keyword(s):  
Wind Speed ◽  
Test Results ◽  
Power Requirement ◽  
Induction Generators ◽  
Detailed Method ◽  
Three Phase ◽  
Control Scheme ◽  
Bridge Rectifier ◽  
Constant Magnitude ◽  
Set Up

A DSP based closed-loop system has been developed for wind-driven three-phase Self-Excited Induction Generators (SEIGs) using a diode bridge rectifier (DBR) followed by an IGBT inverter. This system is meant for supplying isolated ac loads with a voltage of constant magnitude and frequency, for any operating condition of varying nature of wind speed and consumer load. The configuration and implementation of this proposed system have been fully described. The detailed method of analysing and predetermining the performance characteristics of such stand-alone systems has also been explained. Test results obtained on an SEIG operated with the controller built in the laboratory, demonstrate the successful working of both the hardware and software of the control scheme and the usefulness of the set-up as a whole for supplying isolated ac loads. With the varying nature of wind speed, a method of meeting the power balance between the wind power available and the load power requirement has also been explained with extensive Simulation studies.

scholarly journals Mapping flow distortion on oceanographic platforms using computational fluid dynamics

Ocean Science ◽  
2013 ◽  
Vol 9 (5) ◽  
pp. 855-866 ◽  
Author(s):  
N. O'Sullivan ◽  
S. Landwehr ◽  
B. Ward
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Speed ◽  
Close Agreement ◽  
Velocity Fields ◽  
Experimental Measurements ◽  
Flow Distortion ◽  
Direct Measurements ◽  
Computational Fluid Dynamics Cfd ◽  
Set Up

Abstract. Wind speed measurements over the ocean on ships or buoys are affected by flow distortion from the platform and by the anemometer itself. This can lead to errors in direct measurements and the derived parametrisations. Here we computational fluid dynamics (CFD) to simulate the errors in wind speed measurements caused by flow distortion on the RV Celtic Explorer. Numerical measurements were obtained from the finite-volume CFD code OpenFOAM, which was used to simulate the velocity fields. This was done over a range of orientations in the test domain from −60 to +60° in increments of 10°. The simulation was also set up for a range of velocities, ranging from 5 to 25 m s−1 in increments of 0.5 m s−1. The numerical analysis showed close agreement to experimental measurements.

NUMERICAL ANALYSIS OF FENCE TYPE SUPPORT OF APPLE TREES

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Il-Min Kang ◽  
Kyung-Jae Shin ◽  
Young-Ju Lee ◽  
Yu-Hyun Lee ◽  
Hyu-Min Shin ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Wind Speed ◽  
Apple Tree ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Analysis Model ◽  
Apple Trees ◽  
Standard Type ◽  
Set Up ◽  
Test Result

Damages to apple trees caused by typhoons have been repeated every year in Korea. Many types of support of apple trees such as single support, fence-type, matrix-type have been used; however, there is no standard type designed or specified by a code or manual. Most of the support is set up by farmers based on their experience, which results in frequent damage by typhoon. In this study, a prototype support for apple tree suggested by 'Rural Development Administration' is modelled for structural analysis. The previous test results of other trees for wind tunnel test is used as an input of numerical modeling, and the turnover test result of an apple tree is used to assess the strength of the support system. Numerical analysis is conducted for an assumed wind speed based on the test results to estimate the safety of the support. The appropriate steel-pile sizes of fence-type support are suggested based on the analysis result, which might be used as the standard type of support. Analysis results are also used for new design of the support with respect to a different wind speed by using the analysis model.

Evaluation of a new technique for recording the direction of flight of mosquitoes (Diptera: Culicidae) in the field

1978 ◽  
Vol 68 (1) ◽  
pp. 145-152 ◽  
Author(s):  
M. T. Gillies ◽  
M. D. R. Jones ◽  
T. J. Wilkes
Keyword(s):  
Wind Speed ◽  
Ground Level ◽  
The Other ◽  
Electric Grids ◽  
Suction Traps ◽  
Screening Efficiency ◽  
Downwind Side ◽  
A New Technique ◽  
Set Up ◽  
The Relationship

AbstractIn a study in the Gambia on the relationship between wind direction and the direction of flight of mosquitoes, high-voltage electric grids were used as screens in conjunction with suction traps. Mosquitoes contacting or attempting to fly through the grids were electrocuted. The screening efficiency of the grids was estimated to be 75–80%, and the grids had no demonstrable effect on wind speed. The traps were set up in pairs with their mouths at ground level, one trap in each pair being screened on the upwind and the other on the downwind side. In this way, the mosquitoes could be segregated into those that were flying predominantly upwind and predominantly downwind, respectively. The results indicated that some 64% were flying upwind at this level, but this proportion varied considerably over a period of days, with nightly extremes of 87 and 43%; there was little difference between species. This variation was not correlated with wind speed, but there was some evidence that the presence of moonlight led to a greater degree of upwind flight.

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