scholarly journals A study on flow as affected by the shape and wind speed of ventilated seat

2018 ◽  
Vol 7 (3.3) ◽  
pp. 311
Author(s):  
Kye Kwang Choi ◽  
Jae Ung Cho
Keyword(s):  
Statistical Analysis ◽  
Wind Speed ◽  
Flow Path ◽  
Maximum Speed ◽  
Maximum Pressure ◽  
Wind Speeds ◽  
Ansys Cfx ◽  
Design Factors

Background/Objectives: We studied the ventilated seats with amenities. The study has its purpose in checking the flow as affected by the shape of the ventilated seats and thereby acquiring the design factors.Methods/Statistical analysis: In order to acquire the design factors for ventilated seats as affected by the shapes and wind speeds of the different models, we used CATIA program to design the shape, of which the flow was analyzed with ANSYS CFX program. Thus, we have acquired the design factors for ventilated seats, which data can be used to ensure higher levels of efficiency as compared to the shapes before.Findings: For analyzing, we placed an inlet at the vent at the bottom and placed an outlet at the top by setting a boundary around it. From the setup, which had the initial wind speed at 15m/s, the wind speed within the boundary was 29.91m/s for model 1 and 44.81m/s for model 2. At the initial wind speed of 30m/s, we got a wind speed of 60.25m/s for model 1 and 88.60m/s for model 2. As for the pressure and speed in the flow path as the initial wind speed of 15m/s, we got the maximum pressure of 100.60kPa and the maximum speed of 29.45m/s. For model 2, we got the maximum pressure of 102.30kPa and the maximum speed of 44.81m/s. At the initial wind speed of 30m/s, we got the maximum pressure of 102.30kPa and the maximum speed of 60.25m/s for model 1. For model 2, we got the maximum pressure of 105.10kPa and the maximum speed of 88.60m/s.Improvements/Applications: Through the data obtained from this analysis, the varied seat structure for additional amenities can be improved and applied with more design factors.  

scholarly journals A Design and Construction of a Wind Tunnel for Engineering Laboratories

2018 ◽  
Vol 192 ◽  
pp. 02069
Author(s):  
Chalida U-tapao ◽  
Seksun Moryadee
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Test Area ◽  
Maximum Pressure ◽  
Maximum Height ◽  
Wind Speeds ◽  
Air Blower ◽  
And Control ◽  
The Relationship ◽  
Design And Construction

The propose of this research is to demonstrate a design and construction of a wind tunnel for engineering laboratories in order to study the principles and control wind speeds in the wind tunnel. In an experiment in aerodynamics and engineering, we found that diffuser must have a length equal to or more than twice the length of the test in order to prevent the turbulent flow in the test area. The wind speed control system uses Inverter to control a 3-phase frequency of electricity supplied to air blower. In the experiment, the frequency was adjusted in the range from 20.00 to 50.00 Hz. Experiment results show that wind speeds during the test area are in the range of 14.50 to 38.50 meters per second, and the relationship between frequency (Y) and wind speed (X) during the test is linear as follows: Y = (0.7945 × (X-20)) + 14.629. The maximum pressure is 90.31 kilograms per square meter. This wind tunnel can be used to design buildings with a maximum height of 20 meters according to the Bangkok Metropolis Building Control (2001).

A Study on Various Aerodynamic Effects of Pointed Tip Blade

2015 ◽  
Author(s):  
Shrabanti Roy ◽  
Kyoungsoo Lee ◽  
Ziaul Huque ◽  
Raghava Kommalapati
Keyword(s):  
Wind Speed ◽  
Pressure Coefficient ◽  
High Wind ◽  
Wind Speeds ◽  
Ansys Cfx ◽  
Simulation Results ◽  
The Difference ◽  
Torque Values ◽  
Nrel Phase Vi ◽  
Thrust And Torque

A wind turbine blade performance depends on various parameters of which the shape of the blade is one of the most important one. In this work the shape of the tip of original NREL Phase-VI blade (S809 airfoil) has been modified to determine the changes in the blade aerodynamic performance. The chord length of new blade is kept similar to the original NREL blade up to 90% of the span. Last 10% was modified to a pointed tip at the pitch axis. This paper presents a comparative study of the effect of pointed tip on aerodynamic loads. CFD simulations were performed on both original NREL shape and pointed tip shape blades. The simulation results of pointed tip blade were compared with both experimental and simulation results of original blade. Ansys geometry modeler was used to draw the geometry and to generate the grids. Ansys CFX solver and post processor were used for simulation and calculation of the results. To predict the near wall transitional effect SST Gamma Theta turbulence model was used. Results of pressure coefficient along the chord at various blade sections of the pointed tip blade were found to be almost similar to the original NREL blade CFD results. Tangential and normal force along the span of pointed tip blade at different wind speeds showed some similarity in results compared with CFD results of original NREL blade. From the velocity contour the separation of flow with the increase of wind speed can clearly be observed. Thrust and torque effects are also observed at various wind speeds. The torque values for the pointed tip blade were found to be higher in the pre-stall and stall region but slightly lower in post-stall region. But compared to the torque values the difference in thrust at the same region is found to be negligible. Pointed tip thrust values are in better agreement at high wind speeds with respect to the experimental data. The flow separation at high wind speed is also found to be less with pointed tip blade compared to the original blade.

scholarly journals PENGARUH KECEPATAN ANGIN DAN VARIASI JUMLAH SUDU TERHADAP UNJUK KERJA TURBIN ANGIN POROS HORIZONTAL

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Firman Aryanto ◽  
Made Mara ◽  
Made Nuarsa
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Mechanical Energy ◽  
Performance Testing ◽  
Horizontal Axis ◽  
Power Coefficient ◽  
Speed Ratio ◽  
Maximum Speed ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds

The wind turbine is a device that converts wind energy into mechanical energy and then converted into electrical energy through a generator. Horizontal axis wind turbines can increase the efficiency to get the maximum power coefficient. One was using the blade numerous. Maximum efisiensi system will increase the number of watts (power) generated so as to obtain a certain number of watts by simply using the number of windmills lessThe object of this research is the performance testing horizontal axis wind turbine with wind speed variation and variation in terms of the number of blade Efisiensi system (𝜂 )  and Tip Speed Ratio (TSR). Research conducted with the wind coming from the source to the Wind Tunnel fan to direct wind. Wind speed is used there are three variations of the 3 m/s, 3.5 m/s, and 4 m/s and varying the amount of blade that is 3, 4, 5 and 6 blade.The results showed that the best 𝜂  values obtained at a maximum wind speed of 4 m / s and the number of blade 5 with a value of 3.07% 𝜂, whereas 𝜂 smallest value obtained at wind speeds of 3 m/s and the number of blade 3 that the value of 0.05% 𝜂. For TSR maximum value at a maximum speed of 4 m/s occurred in the number of blade 5 is equal to λ = 2.11, while the lowest value at wind speeds of 3 m/s resulting in blade number 3 is equal to λ = 1.49.

scholarly journals Diurnal Variations in Surface Wind over the Tibetan Plateau

Atmosphere ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 112 ◽  
Author(s):  
Yufei Zhao ◽  
Jianping Li ◽  
Qiang Zhang ◽  
Xiaowei Jiang ◽  
Aixia Feng
Keyword(s):  
Wind Speed ◽  
Tibetan Plateau ◽  
Qaidam Basin ◽  
Surface Wind ◽  
Diurnal Variations ◽  
Maximum Speed ◽  
Daily Maximum ◽  
Eastern Region ◽  
The Tibetan Plateau ◽  
Wind Speeds

This study uses hourly surface wind direction and wind speed observations from 53 meteorological stations on the Tibetan Plateau (TP) (70–105° E, 25–45° N) between 1995 and 2017 to investigate diurnal variations in the surface wind. The results show large diurnal variations in surface wind on the TP. The minimum wind speed occurs in the morning and the maximum in the afternoon. In all four seasons, the prevailing meridional wind is a southerly, and this is typically evident for more than two-thirds of each day. However, in the mornings during December–February and September–November, this southerly wind is replaced by a northerly, but remains southerly in the afternoon. The TP shows remarkable regional characteristics with respect to diurnal variations in wind speed. In the eastern region, the minimum and maximum daily wind speeds occur about 1 h later than in the west. Among the 53 meteorological stations, 79% observed that it took less time for the minimum speed to rise to the maximum speed than for the maximum to drop to the minimum. The blocking effect of the high surrounding terrain causes the diurnal variations seen in the surface winds at the three stations in the Qaidam Basin to differ significantly from those observed at the other stations elsewhere on the plateau. These Qaidam Basin stations recorded their maximum wind speeds around noon, with the minimum at dusk, which is around 1900 LST. The EOF1 (EOF = empirical orthogonal function) of the hourly wind speed on the TP indicates the key daily circulation feature of the region; i.e., the wind speed is high in the afternoon and low in the morning. The EOF2 reflects the regional differences in the diurnal variations of wind speed on the TP; i.e., the eastern region reaches the daily maximum and minimum wind speeds slightly later than the western region.

Probabilistic model of combined wind and ice loads on overhead power line conductors

2003 ◽  
Vol 30 (4) ◽  
pp. 704-710 ◽  
Author(s):  
Konstantin Savadjiev ◽  
Masoud Farzaneh
Keyword(s):  
Statistical Analysis ◽  
Wind Speed ◽  
Transmission Lines ◽  
Probabilistic Model ◽  
Electrical Power ◽  
Initial Distribution ◽  
Climatic Conditions ◽  
Reduction Factor ◽  
Wind Speeds ◽  
Ice Loads

There is evidence that extreme ice loads combined with moderately high winds may cause catastrophic damage to overhead power lines and prolonged periods of electrical power outage. In this paper, a probabilistic model for combined wind and ice loads was developed for establishing realistic and conservative criteria for design and normalization. The proposed model combines icing of extreme thickness with a moderate wind speed, Vice, reduced by a reduction factor, kr, with respect to the extreme wind speed, Vmax. The evaluation of kr, which is the main purpose of this paper, is done by means of statistical analysis of samples taken from the same initial distribution of hourly wind speeds, Vh. The size of samples corresponds to the average annual icing persistency period, Tipp, observed in the climatic conditions of Quebec. This period, which was established in an earlier study by the authors using statistical analysis of data from the Hydro-Québec passive ice meter (PIM) network, is evaluated to be on average 144 h/year. It was found that kr ranges from 0.4 to 0.7, mainly as a function of the coefficient of variation (COV) of the initial distribution of wind speeds and the return period prescribed for extreme climatic loads.Key words: combined wind and ice loads, probabilistic model, overhead transmission lines.

scholarly journals Statistical Analysis of the Average Wind Speeds and Maximum Wind Speed (Gust Winds) at a Location in Abuja, Nigeria

OALib ◽  
2021 ◽  
Vol 08 (12) ◽  
pp. 1-22
Author(s):  
Enoch O. Elemo ◽  
Efua A. Ogobor ◽  
George A. Alagbe ◽  
Benjamin G. Ayantunji ◽  
Otonye E. Mangete ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Wind Speed ◽  
Maximum Wind Speed ◽  
Maximum Wind ◽  
Wind Speeds ◽  
Average Wind

SHAPING OF AN AUTONOMOUS POWER SYSTEM FOR GUARANTEED POWER SUPPLY WITH THE PREDOMINANCE WIND ENERGY

2018 ◽  
pp. 28-50
Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva
Keyword(s):  
Energy Storage ◽  
Wind Speed ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Energy Demand ◽  
Diesel Generator ◽  
Average Wind Speed ◽  
Wind Speeds ◽  
Average Wind

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.

التغير المناخي واثره في المقنن المائي لمحصول العنب في محافظة ديالى

2019 ◽  
Vol 1 (34) ◽  
pp. 391-422
Author(s):  
اشواق حسن حميد صالح
Keyword(s):  
Climate Change ◽  
Statistical Analysis ◽  
Wind Speed ◽  
Extreme Temperature ◽  
Solar Brightness ◽  
The Subject ◽  
Climate Station ◽  
The Times ◽  
High Level ◽  
Very High

Climate change and its impact on water resources is the problem of the times. Therefore, this study is concerned with the subject of climate change and its impact on the water ration of the grape harvest in Diyala Governorate. The study was based on the data of the Khanaqin climate station for the period 1973-2017, (1986-2017) due to lack of data at governorate level. The general trend of the elements of the climate and its effect on the water formula was extracted. The equation of change was extracted for the duration of the study. The statistical analysis was also used between the elements of the climate (actual brightness, normal temperature, micro and maximum degrees Celsius, wind speed m / s, relative humidity% The results of the statistical analysis confirm that the water ration for the study area is based mainly on the X7 evaporation / netting variable, which is affected by a set of independent variables X1 Solar Brightness X4 X5 Extreme Temperature Wind Speed ​​3X Minimal Temperature and Very High Level .

scholarly journals Analysis of Performance of the Wind-Driven Pulverizing Aerator Based on Average Wind Speeds in the Conditions of Góreckie Lake

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2796
Author(s):  
Andrzej Osuch ◽  
Ewa Osuch ◽  
Stanisław Podsiadłowski ◽  
Piotr Rybacki
Keyword(s):  
Mathematical Model ◽  
Wind Speed ◽  
Water Pump ◽  
Average Wind Speed ◽  
Flow Rates ◽  
Wind Speeds ◽  
Average Wind ◽  
Flow Through ◽  
Analysis Of Performance ◽  
Research Period

In the introduction to this paper, the characteristics of Góreckie lake and the construction and operation of the wind-driven pulverizing aerator are presented. The purpose of this manuscript is to determine the efficiency of the pulverizing aerator unit in the windy conditions of Góreckie Lake. The efficiency of the pulverization aerator depends on the wind conditions at the lake. It was necessary to conduct thorough research to determine the efficiency of water flow through the pulverization segment (water pump). It was necessary to determine the rotational speed of the paddle wheel, which depended on the average wind speed. Throughout the research period, measurements of hourly average wind speed were carried out. It was possible to determine the efficiency of the machine by developing a dedicated mathematical model. The latest method was used in the research, consisting of determining the theoretical volumetric flow rates of water in the pulverizing aerator unit, based on average hourly wind speeds. Pulverization efficiency under the conditions of Góreckie Lake was determined based on 6600 average wind speeds for spring, summer and autumn, 2018. Based on the model, the theoretical efficiency of the machine was calculated, which, under the conditions of Góreckie Lake, amounted to 75,000 m3 per year.

scholarly journals Optimization of a Small Wind Power Plant for Annual Wind Speed Distribution

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1587
Author(s):  
Krzysztof Wrobel ◽  
Krzysztof Tomczewski ◽  
Artur Sliwinski ◽  
Andrzej Tomczewski
Keyword(s):  
Wind Speed ◽  
Power Plant ◽  
Wind Power ◽  
Power Plants ◽  
Control Method ◽  
Wind Power Plant ◽  
Switched Reluctance ◽  
Wind Speeds ◽  
Wind Speed Distribution ◽  
And Control

This article presents a method to adjust the elements of a small wind power plant to the wind speed characterized by the highest annual level of energy. Tests were carried out on the basis of annual wind distributions at three locations. The standard range of wind speeds was reduced to that resulting from the annual wind speed distributions in these locations. The construction of the generators and the method of their excitation were adapted to the characteristics of the turbines. The results obtained for the designed power plants were compared with those obtained for a power plant with a commercial turbine adapted to a wind speed of 10 mps. The generator structure and control method were optimized using a genetic algorithm in the MATLAB program (Mathworks, Natick, MA, USA); magnetostatic calculations were carried out using the FEMM program; the simulations were conducted using a proprietary simulation program. The simulation results were verified by measurement for a switched reluctance machine of the same voltage, power, and design. Finally, the yields of the designed generators in various locations were determined.

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